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Alzayed NT, Alzuabi AH, Alqusaimi RA, El-Anany EA, Alholle A, Aboelanine AH, Omar S, Alsafi R, Elmonairy AA, Alali FJ, Alahmad A, Alsharhan H, Albash B, Marafi D. Tribal Founder EMC1 Variant in 5 Kuwaiti Families Expands Phenotypic Spectrum of EMC1-Related Disorder. Neurol Genet 2024; 10:e200156. [PMID: 38784058 PMCID: PMC11115761 DOI: 10.1212/nxg.0000000000200156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/18/2024] [Indexed: 05/25/2024]
Abstract
Background and Objectives The endoplasmic reticulum (ER) membrane protein complex is a conserved multisubunit transmembrane complex that enables energy-independent insertion of newly synthesized membrane proteins into ER membranes, mediating protein folding, phospholipid transfer from ER to mitochondria, and elimination of misfolded proteins. The first subunit of EMC (EMC1) is encoded by EMC1. Both monoallelic de novo and biallelic EMC1 variants have been identified to cause cerebellar atrophy, visual impairment, and psychomotor retardation (CAVIPMR) [OMIM #616875]. Eight families with biallelic EMC1 variants and CAVIPMR have been reported. Here, we describe 8 individuals from 5 Kuwaiti families from the same tribe, with the previously reported homozygous pathogenic missense EMC1 variant [c.245C>T:p.(Thr82Met)] and CAVIPMR. Methods Proband exome sequencing was performed in 3 families, while targeted molecular testing for EMC1 [c.245C>T:p.(Thr82Met)] variant was performed in the other 2 families based on strong clinical suspicion and tribal origin. Sanger sequencing confirmed variant segregation with disease in all families. Results We identified 8 individuals from 5 Kuwaiti families with the homozygous pathogenic EMC1 variant [c.245C>T:p.(Thr82Met)] previously reported in a Turkish family with CAVIPMR. The variant was absent from Kuwait Medical Genetic Center database, thus unlikely to represent a population founder allelic variant. The average age at symptom onset was 11 weeks, with all families reporting either visual abnormalities, hypotonia, and/or global developmental delay (GDD) as the presenting features. Shared clinical features included GDD (8/8), microcephaly (8/8), truncal hypotonia (8/8), visual impairment (7/7), and failure to thrive (7/7). Other common features included hyperreflexia (5/6; 83%), peripheral hypertonia (3/5; 60%), dysmorphism (3/6; 50%), epilepsy (4/8; 50%), and chorea (3/8; 36%). Brain imaging showed cerebellar atrophy in 4/7 (57%) and cerebral atrophy in 3/6 (50%) individuals. Discussion The presence of exact biallelic homozygous EMC1 variant in 5 Kuwaiti families from the same tribe suggests a tribal founder allelic variant. The clinical features in this study are consistent with the phenotypic spectrum of EMC1-associated CAVIPMR in previous reports. The presence of chorea, first noted in this study, further expands the phenotypic spectrum. Our findings emphasize the importance of targeted EMC1 variant [c.245C>T:p.(Thr82Met)] testing for infants from affected tribe who present with visual impairment, GDD, and hypotonia.
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Affiliation(s)
- Nada T Alzayed
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Abdullah H Alzuabi
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Reem A Alqusaimi
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Ehab A El-Anany
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Abdullah Alholle
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Ashraf H Aboelanine
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Sherief Omar
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Rasha Alsafi
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Alaa A Elmonairy
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Fatemah J Alali
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Ahmad Alahmad
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Hind Alsharhan
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Buthaina Albash
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
| | - Dana Marafi
- From the College of Medicine (N.T.A., A.H. Alzuabi, R.A.A.), Health Science Center, Kuwait University; Section of Child Neurology (E.A.E.-A., D.M.), Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya; Kuwait Medical Genetics Centre (A. Alholle, A.H. Aboelanine, S.O., A.A.E., F.J.A., A. Alahmad, H.A., D.M.), Ministry of Health, Sulaibikhat; Department of Pediatrics (R.A., B.A.), Adan Hospital, Ministry of Health, Hadiya; Department of Pediatrics (H.A., D.M.), College of Medicine, Kuwait University, Safat; and Department of Pediatrics (H.A.), Farwaniya Hospital, Ministry of Health, Sabah Al-Nasser, Kuwait
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Marafi D. Founder mutations and rare disease in the Arab world. Dis Model Mech 2024; 17:dmm050715. [PMID: 38922202 PMCID: PMC11225585 DOI: 10.1242/dmm.050715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024] Open
Abstract
Founder mutations are disease-causing variants that occur frequently in geographically or culturally isolated groups whose shared ancestor(s) carried the pathogenic variant. While some disease alleles may vanish from the genetic pool due to natural selection, variants with weaker effects may survive for a long time, thereby enhancing the prevalence of some rare diseases. These are predominantly autosomal recessive diseases but can also be autosomal dominant traits with late-onset or mild phenotypes. Cultural practices, such as endogamy and consanguinity, in these isolated groups lead to higher prevalence of such rare diseases compared to the rest of the population and worldwide. In this Perspective, we define population isolates and the underlying genetic mechanisms for accumulating founder mutations. We also discuss the current and potential scientific, clinical and public-health implications of studying founder mutations in population isolates around the world, with a particular focus on the Arab population.
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Affiliation(s)
- Dana Marafi
- Department of Pediatrics, College of Medicine, Kuwait University, P.O. Box 24923, 13110 Safat, Kuwait
- Section of Child Neurology, Department of Pediatrics, Adan Hospital, Ministry of Health, Hadiya 52700, Kuwait
- Kuwait Medical Genetics Centre, Ministry of Health, Sulaibikhat 80901, Kuwait
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Munir A, Afsar S, Rehman AU. A systematic review of inherited retinal dystrophies in Pakistan: updates from 1999 to April 2023. BMC Ophthalmol 2024; 24:55. [PMID: 38317096 PMCID: PMC10840256 DOI: 10.1186/s12886-024-03319-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 01/19/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Inherited retinal degenerations (IRDs) are a group of rare genetic conditions affecting retina of the eye that range in prevalence from 1 in 2000 to 1 in 4000 people globally. This review is based on a retrospective analysis of research articles reporting IRDs associated genetic findings in Pakistani families between 1999 and April 2023. METHODS Articles were retrieved through survey of online sources, notably, PubMed, Google Scholar, and Web of Science. Following a stringent selection criterion, a total of 126 research articles and conference abstracts were considered. All reported variants were cross-checked and validated for their correct genomic nomenclature using different online resources/databases, and their pathogenicity scores were explained as per ACMG guidelines. RESULTS A total of 277 unique sequence variants in 87 distinct genes, previously known to cause IRDs, were uncovered. In around 70% cases, parents of the index patient were consanguineously married, and approximately 88.81% of the detected variants were found in a homozygous state. Overall, more than 95% of the IRDs cases were recessively inherited. Missense variants were predominant (41.88%), followed by Indels/frameshift (26.35%), nonsense (19.13%), splice site (12.27%) and synonymous change (0.36%). Non-syndromic IRDs were significantly higher than syndromic IRDs (77.32% vs. 22.68%). Retinitis pigmentosa (RP) was the most frequently observed IRD followed by Leber's congenital amaurosis (LCA). Altogether, mutations in PDE6A gene was the leading cause of IRDs in Pakistani families followed by mutations in TULP1 gene. CONCLUSION In summary, Pakistani families are notable in expressing recessively inherited monogenic disorders including IRDs likely due to the highest prevalence of consanguinity in the country that leads to expression of rare pathogenic variants in homozygous state.
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Affiliation(s)
- Asad Munir
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan
| | - Salma Afsar
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan
| | - Atta Ur Rehman
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan.
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AlAbdi L, Maddirevula S, Shamseldin HE, Khouj E, Helaby R, Hamid H, Almulhim A, Hashem MO, Abdulwahab F, Abouyousef O, Alqahtani M, Altuwaijri N, Jaafar A, Alshidi T, Alzahrani F, Alkuraya FS. Diagnostic implications of pitfalls in causal variant identification based on 4577 molecularly characterized families. Nat Commun 2023; 14:5269. [PMID: 37644014 PMCID: PMC10465531 DOI: 10.1038/s41467-023-40909-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
Despite large sequencing and data sharing efforts, previously characterized pathogenic variants only account for a fraction of Mendelian disease patients, which highlights the need for accurate identification and interpretation of novel variants. In a large Mendelian cohort of 4577 molecularly characterized families, numerous scenarios in which variant identification and interpretation can be challenging are encountered. We describe categories of challenges that cover the phenotype (e.g. novel allelic disorders), pedigree structure (e.g. imprinting disorders masquerading as autosomal recessive phenotypes), positional mapping (e.g. double recombination events abrogating candidate autozygous intervals), gene (e.g. novel gene-disease assertion) and variant (e.g. complex compound inheritance). Overall, we estimate a probability of 34.3% for encountering at least one of these challenges. Importantly, our data show that by only addressing non-sequencing-based challenges, around 71% increase in the diagnostic yield can be expected. Indeed, by applying these lessons to a cohort of 314 cases with negative clinical exome or genome reports, we could identify the likely causal variant in 54.5%. Our work highlights the need to have a thorough approach to undiagnosed diseases by considering a wide range of challenges rather than a narrow focus on sequencing technologies. It is hoped that by sharing this experience, the yield of undiagnosed disease programs globally can be improved.
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Affiliation(s)
- Lama AlAbdi
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ebtissal Khouj
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rana Helaby
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Halima Hamid
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Aisha Almulhim
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais O Hashem
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Omar Abouyousef
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mashael Alqahtani
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Norah Altuwaijri
- Department of Clinical Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amal Jaafar
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tarfa Alshidi
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema Alzahrani
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia.
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Bizzari S, Nair P, Hana S, Deepthi A, Al-Ali MT, Al-Gazali L, El-Hayek S. Spectrum of genetic disorders and gene variants in the United Arab Emirates national population: insights from the CTGA database. Front Genet 2023; 14:1177204. [PMID: 37214420 PMCID: PMC10194840 DOI: 10.3389/fgene.2023.1177204] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/17/2023] [Indexed: 05/24/2023] Open
Abstract
Like many other Arab countries, the United Arab Emirates (UAE) has a relatively high prevalence of genetic disorders. Here we present the first review and analysis of all genetic disorders and gene variants reported in Emirati nationals and hosted on the Catalogue for Transmission Genetics in Arabs (CTGA), an open-access database hosting bibliographic data on human gene variants associated with inherited or heritable phenotypes in Arabs. To date, CTGA hosts 665 distinct genetic conditions that have been described in Emiratis, 621 of which follow a clear Mendelian inheritance. Strikingly, over half of these are extremely rare according to global prevalence rates, predominantly with an autosomal recessive mode of inheritance. This is likely due to the relatively high consanguinity rates within the Emirati population. The 665 conditions include disorders that are unique to the Emirati population, as well as clearly monogenic disorders that have not yet been mapped to a causal genetic locus. We also describe 1,365 gene variants reported in Emiratis, most of which are substitutions and over half are classified as likely pathogenic or pathogenic. Of these, 235 had not been reported on the international databases dbSNP and Clinvar, as of December 2022. Further analysis of this Emirati variant dataset allows a comparison of clinical significance as reported by Clinvar and CTGA, where the latter is derived from the study cited. A total of 307 pathogenic/likely pathogenic variants from CTGA's Emirati dataset, were classified as benign, variants of uncertain significance, or were missing a clinical significance or had not been reported by Clinvar. In conclusion, we present here the spectrum of genetic disorders and gene variants reported in Emiratis. This review emphasizes the importance of ethnic databases such as CTGA in addressing the underrepresentation of Arab variant data in international databases and documenting population-specific discrepancies in variant interpretation, reiterating the value of such repositories for clinicians and researchers, especially when dealing with rare disorders.
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Affiliation(s)
- Sami Bizzari
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Pratibha Nair
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Sayeeda Hana
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Asha Deepthi
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | | | - Lihadh Al-Gazali
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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Aziz N, Ullah M, Rashid A, Hussain Z, Shah K, Awan A, Khan M, Ullah I, Rehman AU. A novel homozygous missense substitution p.Thr313Ile in the PDE6B gene underlies autosomal recessive retinitis pigmentosa in a consanguineous Pakistani family. BMC Ophthalmol 2023; 23:116. [PMID: 36959549 PMCID: PMC10035148 DOI: 10.1186/s12886-023-02845-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 03/07/2023] [Indexed: 03/25/2023] Open
Abstract
BACKGROUND Retinitis pigmentosa (RP) is one of the most frequent hereditary retinal diseases that often starts with night blindness and eventually leads to legal blindness. Our study aimed to identify the underlying genetic cause of autosomal recessive retinitis pigmentosa (arRP) in a consanguineous Pakistani family. METHODS Following a detailed ophthalmological examination of the patients by an ophthalmologist, whole-exome sequencing was performed on the proband's DNA to delineate the genetic cause of RP in the family. In-depth computational methods, in-silico analysis, and familial co-segregation study were performed for variant detection and validation. RESULTS We studied an inbred Pakistani family with two siblings affected by retinitis pigmentosa. The proband, a 32 years old female, was clinically diagnosed with RP at the age of 6 years. A classical night blindness symptom was reported in the proband since her early childhood. OCT report showed a major reduction in the outer nuclear layer and the ellipsoid zone width, leading to the progression of the disease. Exome sequencing revealed a novel homozygous missense mutation (c.938C > T;p.Thr313Ile) in exon 12 of the PDE6B gene. The mutation p.Thr313Ile co-segregated with RP phenotype in the family. The altered residue (p.Thr313) was super conserved evolutionarily across different vertebrate species, and all available in silico tools classified the mutation as highly pathogenic. CONCLUSION We present a novel homozygous pathogenic mutation in the PDE6B gene as the underlying cause of arRP in a consanguineous Pakistani family. Our findings highlight the importance of missense mutations in the PDE6B gene and expand the known mutational repertoire of PDE6B-related RP.
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Affiliation(s)
- Nobia Aziz
- Department of Biotechnology and Genetic Engineering, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan
| | - Mukhtar Ullah
- Institute of Molecular and Clinical Ophthalmology Basel, University of Basel, Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Abdur Rashid
- Department of Higher Education Archives and Libraries Peshawar, Government of Khyber Pakhtunkhwa, Peshawar, Pakistan
| | - Zubair Hussain
- Department of Biotechnology, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
| | - Khadim Shah
- Department of Biotechnology, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
| | - Azeem Awan
- LRBT Secondary Eye Hospital, Reerah Galla, Balakot Road, Mansehra, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Khan
- Department of Biotechnology and Genetic Engineering, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan
| | - Inam Ullah
- Department of Biotechnology and Genetic Engineering, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan
| | - Atta Ur Rehman
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan.
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Salam MAE, Salama K, Selim YMM, Saad M, Rady R, Alawbathani S, Schroeder S, Elmonem MA, Elkhateeb N. Three siblings with variable degrees of neuromuscular involvement and congenital sideroblastic anemia: A peculiar phenotype and a surprise genotypic explanation. Ann Hum Genet 2023. [PMID: 36916508 DOI: 10.1111/ahg.12505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 03/16/2023]
Abstract
INTRODUCTION Congenital sideroblastic anemias (CSAs) are a group of inherited bone-marrow disorders manifesting with erythroid hyperplasia and ineffective erythropoiesis. METHODS We describe a detailed clinical and genetic characterization of three siblings with CSA. RESULTS Two of them had limb-girdle myopathy and global developmental delay. The two elder siblings performed allogenic hematopoietic stem-cell transplantation 5 and 3 years prior with stabilization of the hematological features. Exome sequencing in the non-transplanted sibling revealed a novel homozygous nonsense variant in SLC25A38 gene NM_017875.2:c.559C > T; p.(Arg187*) causing autosomal-recessive sideroblastic anemia type-2, and a second homozygous pathogenic previously reported variant in GMPPB gene NM_013334.3:c.458C > T; p.(Thr153Ile) causing autosomal-recessive muscular dystrophy-dystroglycanopathy type B14. With the established diagnosis, hematopoietic stem cell transplantation is now being scheduled for the youngest sibling, and a trial therapy with acetylcholine esterase inhibitors was started for the two neurologically affected patients with partial clinical improvement. CONCLUSION This family emphasizes the importance of whole-exome sequencing for familial cases with complex phenotypes and vague neurological manifestations.
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Affiliation(s)
- Mai Abd El Salam
- Department of Pediatrics (Pediatric Hematology Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Khaled Salama
- Department of Pediatrics (Pediatric Hematology Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Yasmeen M M Selim
- Department of Pediatrics (Pediatric Hematology Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mariam Saad
- Department of Pediatrics (Pediatric Hematology Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Rasha Rady
- Department of Pediatrics (Pediatric Hematology Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | | | - Mohamed A Elmonem
- Department of Clinical and Chemical Pathology, Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt.,Egypt Center for Research and Regenerative Medicine (ECRRM), Cairo, Egypt
| | - Nour Elkhateeb
- Department of Pediatrics (Pediatric Neurology and Metabolic Medicine Unit), Kasr Alainy Faculty of Medicine, Cairo University, Cairo, Egypt.,Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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8
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Identification and Characterization of Novel Mutations in Chronic Kidney Disease (CKD) and Autosomal Dominant Polycystic Kidney Disease (ADPKD) in Saudi Subjects by Whole-Exome Sequencing. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58111657. [PMID: 36422197 PMCID: PMC9692281 DOI: 10.3390/medicina58111657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/12/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
Background: Autosomal dominant polycystic kidney disease (ADPKD) is a condition usually caused by a single gene mutation and manifested by both renal and extrarenal features, eventually leading to end-stage renal disease (ESRD) by the median age of 60 years worldwide. Approximately 89% of ADPKD patients had either PKD1 or PKD2 gene mutations. The majority (85%) of the mutations are in the PKD1 gene, especially in the context of family history. Objectives: This study investigated the genetic basis and the undiscovered genes that are involved in ADPKD development among the Saudi population. Materials and Methods: In this study, 11 patients with chronic kidney disease were enrolled. The diagnosis of ADPKD was based on history and diagnostic images: CT images include enlargement of renal outlines, renal echogenicity, and presence of multiple renal cysts with dilated collecting ducts, loss of corticomedullary differentiation, and changes in GFR and serum creatinine levels. Next-generation whole-exome sequencing was conducted using the Ion Torrent PGM platform. Results: Of the 11 Saudi patients diagnosed with chronic kidney disease (CKD) and ADPKD, the most common heterozygote nonsynonymous variant in the PKD1 gene was exon15: (c.4264G > A). Two missense mutations were identified with a PKD1 (c.1758A > C and c.9774T > G), and one patient had a PKD2 mutation (c.1445T > G). Three detected variants were novel, identified at PKD1 (c.1758A > C), PKD2L2 (c.1364A > T), and TSC2 (deletion of a’a at the 3’UTR, R1680C) genes. Other variants in PKD1L1 (c.3813_381 4delinsTG) and PKD1L2 (c.404C > T) were also detected. The median age of end-stage renal disease for ADPK patients in Saudi Arabia was 30 years. Conclusion: This study reported a common variant in the PKD1 gene in Saudi patients with typical ADPKD. We also reported (to our knowledge) for the first time two novel missense variants in PKD1 and PKD2L2 genes and one indel mutation at the 3’UTR of the TSC2 gene. This study establishes that the reported mutations in the affected genes resulted in ADPKD development in the Saudi population by a median age of 30. Nevertheless, future protein−protein interaction studies to investigate the influence of these mutations on PKD1 and PKD2 functions are required. Furthermore, large-scale population-based studies to verify these findings are recommended.
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9
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Rashed WM, Marcotte EL, Spector LG. Germline De Novo Mutations as a Cause of Childhood Cancer. JCO Precis Oncol 2022; 6:e2100505. [PMID: 35820085 DOI: 10.1200/po.21.00505] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Germline de novo mutations (DNMs) represent one of the important topics that need extensive attention from epidemiologists, geneticists, and other relevant stakeholders. Advances in next-generation sequencing technologies allowed examination of parent-offspring trios to ascertain the frequency of germline DNMs. Many epidemiological risk factors for childhood cancer are indicative of DNMs as a mechanism. The aim of this review was to give an overview of germline DNMs, their causes in general, and to discuss their relation to childhood cancer risk. In addition, we highlighted existing gaps in knowledge in many topics of germline DNMs in childhood cancer that need exploration and collaborative efforts.
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Affiliation(s)
- Wafaa M Rashed
- Research Department, Children's Cancer Hospital-Egypt 57357 (CCHE-57357), Cairo, Egypt
| | - Erin L Marcotte
- Division of Epidemiology/Clinical, Research, Department of Pediatrics, University of Minnesota, Minneapolis, MN.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN
| | - Logan G Spector
- Division of Epidemiology/Clinical, Research, Department of Pediatrics, University of Minnesota, Minneapolis, MN.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN
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10
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Susgun S, Kasan K, Yucesan E. Gene Hunting Approaches through the Combination of Linkage Analysis with Whole-Exome Sequencing in Mendelian Diseases: From Darwin to the Present Day. Public Health Genomics 2022; 24:207-217. [PMID: 34237751 DOI: 10.1159/000517102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/27/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In the context of medical genetics, gene hunting is the process of identifying and functionally characterizing genes or genetic variations that contribute to disease phenotypes. In this review, we would like to summarize gene hunting process in terms of historical aspects from Darwin to now. For this purpose, different approaches and recent developments will be detailed. SUMMARY Linkage analysis and association studies are the most common methods in use for explaining the genetic background of hereditary diseases and disorders. Although linkage analysis is a relatively old approach, it is still a powerful method to detect disease-causing rare variants using family-based data, particularly for consanguineous marriages. As is known that, consanguineous marriages or endogamy poses a social problem in developing countries, however, this same condition also provides a unique opportunity for scientists to identify and characterize pathogenic variants. The rapid advancements in sequencing technologies and their parallel implementation together with linkage analyses now allow us to identify the candidate variants related to diseases in a relatively short time. Furthermore, we can now go one step further and functionally characterize the causative variant through in vitro and in vivo studies and unveil the variant-phenotype relationships on a molecular level more robustly. Key Messages: Herein, we suggest that the combined analysis of linkage and exome analysis is a powerful and precise tool to diagnose clinically rare and recessively inherited conditions.
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Affiliation(s)
- Seda Susgun
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey.,Graduate School of Health Sciences, Istanbul University, Istanbul, Turkey
| | - Koray Kasan
- Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Emrah Yucesan
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
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11
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Identification of pharmacogenetic variants from large scale next generation sequencing data in the Saudi population. PLoS One 2022; 17:e0263137. [PMID: 35089958 PMCID: PMC8797234 DOI: 10.1371/journal.pone.0263137] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/12/2022] [Indexed: 11/19/2022] Open
Abstract
It is well documented that drug responses are related to Absorption, Distribution, Metabolism, and Excretion (ADME) characteristics of individual patients. Several studies have identified genetic variability in pharmacogenes, that are either directly responsible for or are associated with ADME, giving rise to individualized treatments. Our objective was to provide a comprehensive overview of pharmacogenetic variation in the Saudi population. We mined next generation sequencing (NGS) data from 11,889 unrelated Saudi nationals, to determine the presence and frequencies of known functional SNP variants in 8 clinically relevant pharmacogenes (CYP2C9, CYP2C19, CYP3A5, CYP4F2, VKORC1, DPYD, TPMT and NUDT15), recommended by the Clinical Pharmacogenetics Implementation Consortium (CPIC), and collectively identified 82 such star alleles. Functionally significant pharmacogenetic variants were prevalent especially in CYP genes (excluding CYP3A5), with 10-44.4% of variants predicted to be inactive or to have decreased activity. In CYP3A5, inactive alleles (87.5%) were the most common. Only 1.8%, 0.7% and 0.7% of NUDT15, TPMT and DPYD variants respectively, were predicted to affect gene activity. In contrast, VKORC1 was found functionally, to be highly polymorphic with 53.7% of Saudi individuals harboring variants predicted to result in decreased activity and 31.3% having variants leading to increased metabolic activity. Furthermore, among the 8 pharmacogenes studied, we detected six rare variants with an aggregated frequency of 1.1%, that among several other ethnicities, were uniquely found in Saudi population. Similarly, within our cohort, the 8 pharmacogenes yielded forty-six novel variants predicted to be deleterious. Based upon our findings, 99.2% of individuals from the Saudi population carry at least one actionable pharmacogenetic variant.
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12
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Mitochondrial "dysmorphology" in variant classification. Hum Genet 2021; 141:55-64. [PMID: 34750646 DOI: 10.1007/s00439-021-02378-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 09/25/2021] [Indexed: 10/19/2022]
Abstract
Mitochondrial disorders are challenging to diagnose. Exome sequencing has greatly enhanced the diagnostic precision of these disorders although interpreting variants of uncertain significance (VUS) remains a formidable obstacle. Whether specific mitochondrial morphological changes can aid in the classification of these variants is unknown. Here, we describe two families (four patients), each with a VUS in a gene known to affect the morphology of mitochondria through a specific role in the fission-fusion balance. In the first, the missense variant in MFF, encoding a fission factor, was associated with impaired fission giving rise to a characteristically over-tubular appearance of mitochondria. In the second, the missense variant in DNAJA3, which has no listed OMIM phenotype, was associated with fragmented appearance of mitochondria consistent with its published deficiency states. In both instances, the highly specific phenotypes allowed us to upgrade the classification of the variants. Our results suggest that, in select cases, mitochondrial "dysmorphology" can be helpful in interpreting variants to reach a molecular diagnosis.
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13
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Catalogue for Transmission Genetics in Arabs (CTGA) Database: Analysing Lebanese Data on Genetic Disorders. Genes (Basel) 2021; 12:genes12101518. [PMID: 34680914 PMCID: PMC8535931 DOI: 10.3390/genes12101518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/21/2021] [Accepted: 09/25/2021] [Indexed: 11/17/2022] Open
Abstract
Lebanon has a high annual incidence of birth defects at 63 per 1000 live births, most of which are due to genetic factors. The Catalogue for Transmission Genetics in Arabs (CTGA) database, currently holds data on 642 genetic diseases and 676 related genes, described in Lebanese subjects. A subset of disorders (14/642) has exclusively been described in the Lebanese population, while 24 have only been reported in CTGA and not on OMIM. An analysis of all disorders highlights a preponderance of congenital malformations, deformations and chromosomal abnormalities and demonstrates that 65% of reported disorders follow an autosomal recessive inheritance pattern. In addition, our analysis reveals that at least 58 known genetic disorders were first mapped in Lebanese families. CTGA also hosts 1316 variant records described in Lebanese subjects, 150 of which were not reported on ClinVar or dbSNP. Most variants involved substitutions, followed by deletions, duplications, as well as in-del and insertion variants. This review of genetic data from the CTGA database highlights the need for screening programs, and is, to the best of our knowledge, the most comprehensive report on the status of genetic disorders in Lebanon to date.
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14
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Bainter W, Platt CD, Park SY, Stafstrom K, Wallace JG, Peters ZT, Massaad MJ, Becuwe M, Salinas SA, Jones J, Beaussant-Cohen S, Jaber F, Yang JS, Walther TC, Orange JS, Rao C, Rakoff-Nahoum S, Tsokos M, Naseem SUR, Al-Tamemi S, Chou J, Hsu VW, Geha RS. Combined immunodeficiency due to a mutation in the γ1 subunit of the coat protein I complex. J Clin Invest 2021; 131:140494. [PMID: 33529166 DOI: 10.1172/jci140494] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/25/2020] [Indexed: 12/14/2022] Open
Abstract
The coat protein I (COPI) complex mediates retrograde trafficking from the Golgi to the endoplasmic reticulum (ER). Five siblings with persistent bacterial and viral infections and defective humoral and cellular immunity had a homozygous p.K652E mutation in the γ1 subunit of COPI (γ1-COP). The mutation disrupts COPI binding to the KDEL receptor and impairs the retrieval of KDEL-bearing chaperones from the Golgi to the ER. Homozygous Copg1K652E mice had increased ER stress in activated T and B cells, poor antibody responses, and normal numbers of T cells that proliferated normally, but underwent increased apoptosis upon activation. Exposure of the mutants to pet store mice caused weight loss, lymphopenia, and defective T cell proliferation that recapitulated the findings in the patients. The ER stress-relieving agent tauroursodeoxycholic acid corrected the immune defects of the mutants and reversed the phenotype they acquired following exposure to pet store mice. This study establishes the role of γ1-COP in the ER retrieval of KDEL-bearing chaperones and thereby the importance of ER homeostasis in adaptive immunity.
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Affiliation(s)
- Wayne Bainter
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Craig D Platt
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Seung-Yeol Park
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Kelsey Stafstrom
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jacqueline G Wallace
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Zachary T Peters
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Michel J Massaad
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Michel Becuwe
- Department of Genetics and Complex Diseases and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Sandra Andrea Salinas
- Division of Immunogenetics, Department of Pediatrics, Morgan Stanley Children's Hospital of New York Presbyterian, Columbia University Irving Medical Center, New York, New York, USA
| | - Jennifer Jones
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Sarah Beaussant-Cohen
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Faris Jaber
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jia-Shu Yang
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Tobias C Walther
- Department of Genetics and Complex Diseases and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Jordan S Orange
- Division of Immunogenetics, Department of Pediatrics, Morgan Stanley Children's Hospital of New York Presbyterian, Columbia University Irving Medical Center, New York, New York, USA
| | - Chitong Rao
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Seth Rakoff-Nahoum
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria Tsokos
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Salem Al-Tamemi
- Department of Child Health, Sultan Qaboos University Hospital, Muscat, Oman
| | - Janet Chou
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Victor W Hsu
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Raif S Geha
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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15
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Morton CC. ASHG 2020 Curt Stern Award introduction: Fowzan Sami Alkuraya. Am J Hum Genet 2021; 108:392-394. [PMID: 33667392 DOI: 10.1016/j.ajhg.2020.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
This article is based on the address given by the author at the 2020 virtual meeting of the American Society of Human Genetics (ASHG) on October 26, 2020. The video of the original address can be found at the ASHG website.
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16
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Alkuraya FS. 2020 Curt Stern Award address: a more perfect clinical genome-how consanguineous populations contribute to the medical annotation of the human genome. Am J Hum Genet 2021; 108:395-399. [PMID: 33667393 DOI: 10.1016/j.ajhg.2020.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This article is based on the address given by the author at the 2020 virtual meeting of the American Society of Human Genetics (ASHG) on October 26, 2020. The video of the original address can be found at the ASHG website.
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17
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Maddirevula S, Shamseldin HE, Sirr A, AlAbdi L, Lo RS, Ewida N, Al-Qahtani M, Hashem M, Abdulwahab F, Aboyousef O, Kaya N, Monies D, Salem MH, Al Harbi N, Aldhalaan HM, Alzaidan H, Almanea HM, Alsalamah AK, Al Mutairi F, Ismail S, Abdel-Salam GMH, Alhashem A, Asery A, Faqeih E, AlQassmi A, Al-Hamoudi W, Algoufi T, Shagrani M, Dudley AM, Alkuraya FS. Exploiting the Autozygome to Support Previously Published Mendelian Gene-Disease Associations: An Update. Front Genet 2020; 11:580484. [PMID: 33456446 PMCID: PMC7806527 DOI: 10.3389/fgene.2020.580484] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/30/2020] [Indexed: 01/06/2023] Open
Abstract
There is a growing interest in standardizing gene-disease associations for the purpose of facilitating the proper classification of variants in the context of Mendelian diseases. One key line of evidence is the independent observation of pathogenic variants in unrelated individuals with similar phenotypes. Here, we expand on our previous effort to exploit the power of autozygosity to produce homozygous pathogenic variants that are otherwise very difficult to encounter in the homozygous state due to their rarity. The identification of such variants in genes with only tentative associations to Mendelian diseases can add to the existing evidence when observed in the context of compatible phenotypes. In this study, we report 20 homozygous variants in 18 genes (ADAMTS18, ARNT2, ASTN1, C3, DMBX1, DUT, GABRB3, GM2A, KIF12, LOXL3, NUP160, PTRHD1, RAP1GDS1, RHOBTB2, SIGMAR1, SPAST, TENM3, and WASHC5) that satisfy the ACMG classification for pathogenic/likely pathogenic if the involved genes had confirmed rather than tentative links to diseases. These variants were selected because they were truncating, founder with compelling segregation or supported by robust functional assays as with the DUT variant that we present its validation using yeast model. Our findings support the previously reported disease associations for these genes and represent a step toward their confirmation.
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Affiliation(s)
- Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amy Sirr
- Pacific Northwest Research Institute, Seattle, WA, United States
| | - Lama AlAbdi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Russell S Lo
- Pacific Northwest Research Institute, Seattle, WA, United States
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mashael Al-Qahtani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Omar Aboyousef
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Namik Kaya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - May H Salem
- Pediatric Nephrology Service, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Naffaa Al Harbi
- Pediatric Nephrology Service, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Hesham M Aldhalaan
- Department of Neuroscience, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hamad Alzaidan
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hadeel M Almanea
- Anatomic Pathology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abrar K Alsalamah
- Vitreoretinal and Uveitis Divisions, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Fuad Al Mutairi
- Medical Genetics Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Abdulaziz Medical City, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Samira Ismail
- Human Genetics & Genome Research Division, Clinical Genetics Department, Center of Excellence of Human Genetics, National Research Centre, Cairo, Egypt
| | - Ghada M H Abdel-Salam
- Human Genetics & Genome Research Division, Clinical Genetics Department, Center of Excellence of Human Genetics, National Research Centre, Cairo, Egypt
| | - Amal Alhashem
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia
| | - Ali Asery
- Section of Pediatric Gastroenterology, Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Amal AlQassmi
- Pediatric Neurology, King Saud Medical City, Riyadh, Saudi Arabia
| | - Waleed Al-Hamoudi
- Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Talal Algoufi
- King Faisal Specialist Hospital and Research Center, Organ Transplant Centre, Riyadh, Saudi Arabia
| | - Mohammad Shagrani
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,King Faisal Specialist Hospital and Research Center, Organ Transplant Centre, Riyadh, Saudi Arabia
| | - Aimée M Dudley
- Pacific Northwest Research Institute, Seattle, WA, United States
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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18
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Salmaninejad A, Motaee J, Farjami M, Alimardani M, Esmaeilie A, Pasdar A. Next-generation sequencing and its application in diagnosis of retinitis pigmentosa. Ophthalmic Genet 2020; 40:393-402. [PMID: 31755340 DOI: 10.1080/13816810.2019.1675178] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Retinitis Pigmentosa (RP) is a major cause of heritable human blindness with a high genetic heterogeneity. It is characterized by the initial degeneration of rod photoreceptors followed by cone photoreceptors. RP is also a prominent reason of visual impairment, by a global prevalence of 1:4000. RP is usually specified with nyctalopia in puberty, followed by concentric visual field loss, that reflects the main impairment of rod photoreceptors; later in the life, as disease progresses, because of cone dysfunction, central vision loss also occurs. A precise molecular diagnosis is crucial for disease characterization and clinical prognosis. DNA sequencing is a powerful tool for deciphering various causes of different human diseases. The arrival of next-generation sequencing (NGS) technologies has diminished sequencing cost and considerably augmented the throughput, making whole-genome sequencing (WGS) a conceivable way for obtaining comprehensive genomic data and a more precise clinical decision. Nevertheless, the advantages gained from NGS technologies are among a number of challenges that must be sufficiently addressed before this technique can be altered from an investigation tools to a helpful method in routine clinical practices. This article aims to provide an overview about NGS technology and its related platforms. The challenges in the analysis and choosing an appropriate NGS method likewise their potential applications in clinical diagnosis are also discussed. The merit of such technique has been reflected in some recent studies where it is shown that using NGS and molecular information could help with clinical diagnosis, providing potential treatment options or changes, up-to-date family counseling and management.
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Affiliation(s)
- Arash Salmaninejad
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Jamshid Motaee
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahsa Farjami
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Maliheh Alimardani
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Alireza Pasdar
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Bioinformatics Research Group, Mashhad University of Medical Sciences, Mashhad, Iran.,Division of Applied Medicine,Medical School, University of Aberdeen, Foresterhill, Aberdeen, UK
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19
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Shaheen R, Alsahli S, Ewida N, Alzahrani F, Shamseldin HE, Patel N, Al Qahtani A, Alhebbi H, Alhashem A, Al-Sheddi T, Alomar R, Alobeid E, Abouelhoda M, Monies D, Al-Hussaini A, Alzouman MA, Shagrani M, Faqeih E, Alkuraya FS. Biallelic Mutations in Tetratricopeptide Repeat Domain 26 (Intraflagellar Transport 56) Cause Severe Biliary Ciliopathy in Humans. Hepatology 2020; 71:2067-2079. [PMID: 31595528 DOI: 10.1002/hep.30982] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 09/27/2019] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND AIMS The clinical consequences of defective primary cilium (ciliopathies) are characterized by marked phenotypic and genetic heterogeneity. Although fibrocystic liver disease is an established ciliopathy phenotype, severe neonatal cholestasis is rarely recognized as such. APPROACH AND RESULTS We describe seven individuals from seven families with syndromic ciliopathy clinical features, including severe neonatal cholestasis (lethal in one and necessitating liver transplant in two). Positional mapping revealed a single critical locus on chromosome 7. Whole-exome sequencing revealed three different homozygous variants in Tetratricopeptide Repeat Domain 26 (TTC26) that fully segregated with the phenotype. TTC26 (intraflagellar transport [IFT] 56/DYF13) is an atypical component of IFT-B complex, and deficiency of its highly conserved orthologs has been consistently shown to cause defective ciliary function in several model organisms. We show that cilia in TTC26-mutated patient cells display variable length and impaired function, as indicated by dysregulated sonic hedgehog signaling, abnormal staining for IFT-B components, and transcriptomic clustering with cells derived from individuals with closely related ciliopathies. We also demonstrate a strong expression of Ttc26 in the embryonic mouse liver in a pattern consistent with its proposed role in the normal development of the intrahepatic biliary system. CONCLUSIONS In addition to establishing a TTC26-related ciliopathy phenotype in humans, our results highlight the importance of considering ciliopathies in the differential diagnosis of severe neonatal cholestasis even in the absence of more typical features.
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Affiliation(s)
- Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Saud Alsahli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Awad Al Qahtani
- Department of Pediatric Gastroenterology & Hepatologist, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Homoud Alhebbi
- Department of Pediatric Gastroenterology & Hepatologist, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Tarfa Al-Sheddi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rana Alomar
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eman Alobeid
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Abdulrahman Al-Hussaini
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Prince Abdullah Bin Khaled Celiac Disease Research Chair, Department of Pediatrics, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Muneerah A Alzouman
- Histopathology Division, Central Military Laboratory and Blood Bank, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Mohammad Shagrani
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,King Faisal Specialist Hospital and Research Center, Organ Transplant Centre, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
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20
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Exploring the Genetic Landscape of Retinal Diseases in North-Western Pakistan Reveals a High Degree of Autozygosity and a Prevalent Founder Mutation in ABCA4. Genes (Basel) 2019; 11:genes11010012. [PMID: 31877759 PMCID: PMC7017091 DOI: 10.3390/genes11010012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Variants in more than 271 different genes have been linked to hereditary retinal diseases, making comprehensive genomic approaches mandatory for accurate diagnosis. We explored the genetic landscape of retinal disorders in consanguineous families from North-Western Pakistan, harboring a population of approximately 35 million inhabitants that remains relatively isolated and highly inbred (~50% consanguinity). We leveraged on the high degree of consanguinity by applying genome-wide high-density single-nucleotide polymorphism (SNP) genotyping followed by targeted Sanger sequencing of candidate gene(s) lying inside autozygous intervals. In addition, we performed whole-exome sequencing (WES) on at least one proband per family. We identified 7 known and 4 novel variants in a total of 10 genes (ABCA4, BBS2, CNGA1, CNGA3, CNGB3, MKKS, NMNAT1, PDE6B, RPE65, and TULP1) previously known to cause inherited retinal diseases. In spite of all families being consanguineous, compound heterozygosity was detected in one family. All homozygous pathogenic variants resided in autozygous intervals ≥2.0 Mb in size. Putative founder variants were observed in the ABCA4 (NM_000350.2:c.214G>A; p.Gly72Arg; ten families) and NMNAT1 genes (NM_022787.3:c.25G>A; p.Val9Met; two families). We conclude that geographic isolation and sociocultural tradition of intrafamilial mating in North-Western Pakistan favor both the clinical manifestation of rare “generic” variants and the prevalence of founder mutations.
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21
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Distinct genetic variation and heterogeneity of the Iranian population. PLoS Genet 2019; 15:e1008385. [PMID: 31550250 PMCID: PMC6759149 DOI: 10.1371/journal.pgen.1008385] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 08/27/2019] [Indexed: 02/07/2023] Open
Abstract
Iran, despite its size, geographic location and past cultural influence, has largely been a blind spot for human population genetic studies. With only sparse genetic information on the Iranian population available, we pursued its genome-wide and geographic characterization based on 1021 samples from eleven ethnic groups. We show that Iranians, while close to neighboring populations, present distinct genetic variation consistent with long-standing genetic continuity, harbor high heterogeneity and different levels of consanguinity, fall apart into a cluster of similar groups and several admixed ones and have experienced numerous language adoption events in the past. Our findings render Iran an important source for human genetic variation in Western and Central Asia, will guide adequate study sampling and assist the interpretation of putative disease-implicated genetic variation. Given Iran's internal genetic heterogeneity, future studies will have to consider ethnic affiliations and possible admixture.
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22
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Nahorski MS, Maddirevula S, Ishimura R, Alsahli S, Brady AF, Begemann A, Mizushima T, Guzmán-Vega FJ, Obata M, Ichimura Y, Alsaif HS, Anazi S, Ibrahim N, Abdulwahab F, Hashem M, Monies D, Abouelhoda M, Meyer BF, Alfadhel M, Eyaid W, Zweier M, Steindl K, Rauch A, Arold ST, Woods CG, Komatsu M, Alkuraya FS. Biallelic UFM1 and UFC1 mutations expand the essential role of ufmylation in brain development. Brain 2019; 141:1934-1945. [PMID: 29868776 PMCID: PMC6022668 DOI: 10.1093/brain/awy135] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 03/23/2018] [Indexed: 12/31/2022] Open
Abstract
The post-translational modification of proteins through the addition of UFM1, also known as ufmylation, plays a critical developmental role as revealed by studies in animal models. The recent finding that biallelic mutations in UBA5 (the E1-like enzyme for ufmylation) cause severe early-onset encephalopathy with progressive microcephaly implicates ufmylation in human brain development. More recently, a homozygous UFM1 variant was proposed as a candidate aetiology of severe early-onset encephalopathy with progressive microcephaly. Here, we establish a locus for severe early-onset encephalopathy with progressive microcephaly based on two families, and map the phenotype to a novel homozygous UFM1 mutation. This mutation has a significantly diminished capacity to form thioester intermediates with UBA5 and with UFC1 (the E2-like enzyme for ufmylation), with resulting impaired ufmylation of cellular proteins. Remarkably, in four additional families where eight children have severe early-onset encephalopathy with progressive microcephaly, we identified two biallelic UFC1 mutations, which impair UFM1-UFC1 intermediate formation with resulting widespread reduction of cellular ufmylation, a pattern similar to that observed with UFM1 mutation. The striking resemblance between UFM1- and UFC1-related clinical phenotype and biochemical derangements strongly argues for an essential role for ufmylation in human brain development. The hypomorphic nature of UFM1 and UFC1 mutations and the conspicuous depletion of biallelic null mutations in the components of this pathway in human genome databases suggest that it is necessary for embryonic survival, which is consistent with the embryonic lethal nature of knockout models for the orthologous genes.
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Affiliation(s)
- Michael S Nahorski
- Cambridge Institute for Medical Research, Wellcome Trust MRC Building Addenbrookes Hospital, Hills Rd, Cambridge, UK
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ryosuke Ishimura
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan
| | - Saud Alsahli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Angela F Brady
- North West Thames Genetics Service, Level 8V, St Mark's Hospital, Northwick Park Hospital Watford Road, Harrow, UK
| | - Anaïs Begemann
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Tsunehiro Mizushima
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo, Japan
| | - Francisco J Guzmán-Vega
- King Abdullah University of Science and Technology, Computational Bioscience Research Center, Division of Biological and Environmental Sciences and Engineering, Thuwal, Saudi Arabia
| | - Miki Obata
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan
| | - Yoshinobu Ichimura
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan
| | - Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shams Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Wafa Eyaid
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Markus Zweier
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren-Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Stefan T Arold
- King Abdullah University of Science and Technology, Computational Bioscience Research Center, Division of Biological and Environmental Sciences and Engineering, Thuwal, Saudi Arabia
| | - C Geoffrey Woods
- Cambridge Institute for Medical Research, Wellcome Trust MRC Building Addenbrookes Hospital, Hills Rd, Cambridge, UK
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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23
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Monies D, Abouelhoda M, Assoum M, Moghrabi N, Rafiullah R, Almontashiri N, Alowain M, Alzaidan H, Alsayed M, Subhani S, Cupler E, Faden M, Alhashem A, Qari A, Chedrawi A, Aldhalaan H, Kurdi W, Khan S, Rahbeeni Z, Alotaibi M, Goljan E, Elbardisy H, ElKalioby M, Shah Z, Alruwaili H, Jaafar A, Albar R, Akilan A, Tayeb H, Tahir A, Fawzy M, Nasr M, Makki S, Alfaifi A, Akleh H, Yamani S, Bubshait D, Mahnashi M, Basha T, Alsagheir A, Abu Khaled M, Alsaleem K, Almugbel M, Badawi M, Bashiri F, Bohlega S, Sulaiman R, Tous E, Ahmed S, Algoufi T, Al-Mousa H, Alaki E, Alhumaidi S, Alghamdi H, Alghamdi M, Sahly A, Nahrir S, Al-Ahmari A, Alkuraya H, Almehaidib A, Abanemai M, Alsohaibaini F, Alsaud B, Arnaout R, Abdel-Salam GMH, Aldhekri H, AlKhater S, Alqadi K, Alsabban E, Alshareef T, Awartani K, Banjar H, Alsahan N, Abosoudah I, Alashwal A, Aldekhail W, Alhajjar S, Al-Mayouf S, Alsemari A, Alshuaibi W, Altala S, Altalhi A, Baz S, Hamad M, Abalkhail T, Alenazi B, Alkaff A, Almohareb F, Al Mutairi F, Alsaleh M, Alsonbul A, Alzelaye S, Bahzad S, Manee AB, Jarrad O, Meriki N, Albeirouti B, Alqasmi A, AlBalwi M, Makhseed N, Hassan S, Salih I, Salih MA, Shaheen M, Sermin S, Shahrukh S, Hashmi S, Shawli A, Tajuddin A, Tamim A, Alnahari A, Ghemlas I, Hussein M, Wali S, Murad H, Meyer BF, Alkuraya FS. Lessons Learned from Large-Scale, First-Tier Clinical Exome Sequencing in a Highly Consanguineous Population. Am J Hum Genet 2019; 104:1182-1201. [PMID: 31130284 DOI: 10.1016/j.ajhg.2019.04.011] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/11/2019] [Indexed: 12/16/2022] Open
Abstract
We report the results of clinical exome sequencing (CES) on >2,200 previously unpublished Saudi families as a first-tier test. The predominance of autosomal-recessive causes allowed us to make several key observations. We highlight 155 genes that we propose to be recessive, disease-related candidates. We report additional mutational events in 64 previously reported candidates (40 recessive), and these events support their candidacy. We report recessive forms of genes that were previously associated only with dominant disorders and that have phenotypes ranging from consistent with to conspicuously distinct from the known dominant phenotypes. We also report homozygous loss-of-function events that can inform the genetics of complex diseases. We were also able to deduce the likely causal variant in most couples who presented after the loss of one or more children, but we lack samples from those children. Although a similar pattern of mostly recessive causes was observed in the prenatal setting, the higher proportion of loss-of-function events in these cases was notable. The allelic series presented by the wealth of recessive variants greatly expanded the phenotypic expression of the respective genes. We also make important observations about dominant disorders; these observations include the pattern of de novo variants, the identification of 74 candidate dominant, disease-related genes, and the potential confirmation of 21 previously reported candidates. Finally, we describe the influence of a predominantly autosomal-recessive landscape on the clinical utility of rapid sequencing (Flash Exome). Our cohort's genotypic and phenotypic data represent a unique resource that can contribute to improved variant interpretation through data sharing.
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Affiliation(s)
- Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mohammed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mirna Assoum
- Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Nabil Moghrabi
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Rafiullah Rafiullah
- Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Naif Almontashiri
- Clinical Molecular and Biochemical Genetics, Taibah University, Madinah 42353, Saudi Arabia
| | - Mohammed Alowain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hamad Alzaidan
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Moeen Alsayed
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Shazia Subhani
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Edward Cupler
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Maha Faden
- Genetics and Metabolism, King Saud Medical Complex, Riyadh 12746, Saudi Arabia
| | - Amal Alhashem
- Pediatrics Department, Prince Sultan Military Medical Complex, Riyadh 12233, Saudi Arabia
| | - Alya Qari
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Aziza Chedrawi
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Hisham Aldhalaan
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Wesam Kurdi
- Obstetrics and Gynecology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Sameena Khan
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Zuhair Rahbeeni
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Maha Alotaibi
- Genetics and Metabolism, King Saud Medical Complex, Riyadh 12746, Saudi Arabia
| | - Ewa Goljan
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hadeel Elbardisy
- Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mohamed ElKalioby
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Zeeshan Shah
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hibah Alruwaili
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Amal Jaafar
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ranad Albar
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia
| | - Asma Akilan
- Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hamsa Tayeb
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Asma Tahir
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mohammed Fawzy
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mohammed Nasr
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Shaza Makki
- Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Abdullah Alfaifi
- Pediatrics Department, Security Forces Hospital, Riyadh 11481, Saudi Arabia
| | - Hanna Akleh
- Academic and Training Affairs, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Suad Yamani
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Dalal Bubshait
- Pediatrics Department, King Fahad Hospital of the University, Al-Khobar 31952, Saudi Arabia
| | - Mohammed Mahnashi
- Genetics and Medicine, King Fahd Central Hospital, Gizan 82666, Saudi Arabia
| | - Talal Basha
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Afaf Alsagheir
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Musad Abu Khaled
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Khalid Alsaleem
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Maisoon Almugbel
- Obstetrics and Gynecology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Manal Badawi
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Fahad Bashiri
- Department of Pediatrics, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh 11461, Saudi Arabia
| | - Saeed Bohlega
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Raashida Sulaiman
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ehab Tous
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Syed Ahmed
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Talal Algoufi
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hamoud Al-Mousa
- Allergy - Immunology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Emadia Alaki
- Allergy - Immunology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Susan Alhumaidi
- Pediatrics Department, King Saud Medical City, Riyadh 12746, Saudi Arabia
| | - Hadeel Alghamdi
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Malak Alghamdi
- Pediatrics Department, King Saud Medical City, Riyadh 12746, Saudi Arabia
| | - Ahmed Sahly
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Shapar Nahrir
- Pediatrics Department, King Saud Medical City, Riyadh 12746, Saudi Arabia
| | - Ali Al-Ahmari
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Hisham Alkuraya
- Vitreoretinal Surgery, Specialized Medical Centre, Riyadh 11564, Saudi Arabia
| | - Ali Almehaidib
- Gastroenterology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mohammed Abanemai
- Gastroenterology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Fahad Alsohaibaini
- Gastroenterology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Bandar Alsaud
- Allergy - Immunology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Rand Arnaout
- Allergy - Immunology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | | | - Hasan Aldhekri
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Suzan AlKhater
- Pediatrics Department, King Fahad Hospital of the University, Al-Khobar 31952, Saudi Arabia; Department of Pediatrics, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam 34221, Saudi Arabia
| | - Khalid Alqadi
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Essam Alsabban
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Turki Alshareef
- Pediatric Nephrology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Khalid Awartani
- Obstetrics and Gynecology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Hanaa Banjar
- Pediatric Pulmonology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Nada Alsahan
- Obstetrics and Gynecology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ibraheem Abosoudah
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Abdullah Alashwal
- Pediatric Endocrine and Metabolism, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Wajeeh Aldekhail
- Gastroenterology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Sami Alhajjar
- Pediatric Infectious Diseases, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Sulaiman Al-Mayouf
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Abdulaziz Alsemari
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Walaa Alshuaibi
- Pediatrics Department, King Khalid University Hospital, Riyadh 12372, Saudi Arabia
| | - Saeed Altala
- Pediatrics Department, Armed Forces Hospital, Khamis Mushait 62451, Saudi Arabia
| | - Abdulhadi Altalhi
- Pediatric Nephrology, King Saud Medical City, Riyadh 12746, Saudi Arabia
| | - Salah Baz
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Muddathir Hamad
- Pediatrics Department, King Khalid University Hospital, Riyadh 12372, Saudi Arabia
| | - Tariq Abalkhail
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Badi Alenazi
- Pediatrics Department, Alyamama Hospital, Riyadh 14222, Saudi Arabia
| | - Alya Alkaff
- Obstetrics and Gynecology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Fahad Almohareb
- Oncology Center, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Fuad Al Mutairi
- King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11564, Saudi Arabia; Medical Genetic Division, Department of Pediatrics, King Abdulaziz Medical City, Riyadh 14611, Saudi Arabia
| | - Mona Alsaleh
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Abdullah Alsonbul
- Pediatric Rheumatology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Somaya Alzelaye
- Pediatric Endocrine and Diabetes, Al Qunfudah General Hospital, Al Qunfudhah 28821, Saudi Arabia
| | - Shakir Bahzad
- Kuwait Medical Genetics Center, Kuwait City 65000, Kuwait
| | - Abdulaziz Bin Manee
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ola Jarrad
- Pediatrics Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Neama Meriki
- Maternal and Fetal Medicine, King Khalid University Hospital, Riyadh 12372, Saudi Arabia
| | - Bassem Albeirouti
- Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Amal Alqasmi
- Pediatrics Department, King Saud Medical City, Riyadh 12746, Saudi Arabia
| | - Mohammed AlBalwi
- Department of Pathology and Laboratory Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Riyadh 11426, Saudi Arabia
| | - Nawal Makhseed
- Pediatrics Department, Alsoor Clinic, Kuwait City 65000, Kuwait
| | - Saeed Hassan
- Pediatrics Department, King Khalid University Hospital, Riyadh 12372, Saudi Arabia
| | - Isam Salih
- Hepatic-Pancreatic Surgery, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Mustafa A Salih
- Department of Pediatrics, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh 11461, Saudi Arabia
| | - Marwan Shaheen
- Hematology and Bone Marrow Transplant, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Saadeh Sermin
- Pediatric Nephrology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Shamsad Shahrukh
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Shahrukh Hashmi
- Hematology and Bone Marrow Transplant, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ayman Shawli
- Department of Pediatrics, King Abdulaziz Medical City, Jeddah 9515, Saudi Arabia
| | - Ameen Tajuddin
- Neurology, King Fahad Hospital, Medina 59046, Saudi Arabia
| | - Abdullah Tamim
- Pediatrics Neurology, King Faisal Specialist Hospital and Research Centre, Jeddah 23433, Saudi Arabia
| | - Ahmed Alnahari
- Pediatric Department, King Fahad Central Hospital, Gizan, 82666, Saudi Arabia
| | - Ibrahim Ghemlas
- Pediatric Hematology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Maged Hussein
- Nephrology Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Sami Wali
- Pediatrics Department, Prince Sultan Military Medical Complex, Riyadh 12233, Saudi Arabia
| | - Hatem Murad
- Neurosciences Department, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; Saudi Diagnostic Laboratories, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia; College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
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Romdhane L, Mezzi N, Hamdi Y, El-Kamah G, Barakat A, Abdelhak S. Consanguinity and Inbreeding in Health and Disease in North African Populations. Annu Rev Genomics Hum Genet 2019; 20:155-179. [PMID: 31039041 DOI: 10.1146/annurev-genom-083118-014954] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
North Africa is defined as the geographical region separated from the rest of the continent by the Sahara and from Europe by the Mediterranean Sea. The main demographic features of North African populations are their familial structure and high rates of familial and geographic endogamy, which have a proven impact on health, particularly the occurrence of genetic diseases, with a greater effect on the frequency and spectrum of the rarest forms of autosomal recessive genetic diseases. More than 500 different genetic diseases have been reported in this region, most of which are autosomal recessive. During the last few decades, there has been great interest in the molecular investigation of large consanguineous North African families. The development of local capacities has brought a substantial improvement in the molecular characterization of these diseases, but the genetic bases of half of them remain unknown. Diseases of known molecular etiology are characterized by their genetic and mutational heterogeneity, although some founder mutations are encountered relatively frequently. Some founder mutations are specific to a single country or a specific ethnic or geographic group, and others are shared by all North African countries or worldwide. The impact of consanguinity on common multifactorial diseases is less evident.
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Affiliation(s)
- Lilia Romdhane
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, 1002 Tunis Belvédère, Tunisia; .,Department of Biology, Faculty of Sciences of Bizerte, Université Tunis Carthage, 7021 Jarzouna, Tunisia
| | - Nessrine Mezzi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, 1002 Tunis Belvédère, Tunisia;
| | - Yosr Hamdi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, 1002 Tunis Belvédère, Tunisia;
| | - Ghada El-Kamah
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo 12622, Egypt
| | - Abdelhamid Barakat
- Laboratoire de Génétique Humaine et Biologie Moléculaire, Département de Recherche Scientifique, Institut Pasteur du Maroc, 20100 Casablanca, Morocco
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, 1002 Tunis Belvédère, Tunisia;
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25
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Shaheen R, Jiang N, Alzahrani F, Ewida N, Al-Sheddi T, Alobeid E, Musaev D, Stanley V, Hashem M, Ibrahim N, Abdulwahab F, Alshenqiti A, Sonmez FM, Saqati N, Alzaidan H, Al-Qattan MM, Al-Mohanna F, Gleeson JG, Alkuraya FS. Bi-allelic Mutations in FAM149B1 Cause Abnormal Primary Cilium and a Range of Ciliopathy Phenotypes in Humans. Am J Hum Genet 2019; 104:731-737. [PMID: 30905400 PMCID: PMC6451727 DOI: 10.1016/j.ajhg.2019.02.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 02/14/2019] [Indexed: 11/30/2022] Open
Abstract
Ciliopathies are clinical disorders of the primary cilium with widely recognized phenotypic and genetic heterogeneity. In two Arab consanguineous families, we mapped a ciliopathy phenotype that most closely matches Joubert syndrome (hypotonia, developmental delay, typical facies, oculomotor apraxia, polydactyly, and subtle posterior fossa abnormalities) to a single locus in which a founder homozygous truncating variant in FAM149B1 was identified by exome sequencing. We subsequently identified a third Arab consanguineous multiplex family in which the phenotype of Joubert syndrome/oral-facial-digital syndrome (OFD VI) was found to co-segregate with the same founder variant in FAM149B1. Independently, autozygosity mapping and exome sequencing in a consanguineous Turkish family with Joubert syndrome highlighted a different homozygous truncating variant in the same gene. FAM149B1 encodes a protein of unknown function. Mutant fibroblasts were found to have normal ciliogenesis potential. However, distinct cilia-related abnormalities were observed in these cells: abnormal accumulation IFT complex at the distal tips of the cilia, which assumed bulbous appearance, increased length of the primary cilium, and dysregulated SHH signaling. We conclude that FAM149B1 is required for normal ciliary biology and that its deficiency results in a range of ciliopathy phenotypes in humans along the spectrum of Joubert syndrome.
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Affiliation(s)
- Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Nan Jiang
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fatema Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Tarfa Al-Sheddi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Eman Alobeid
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Damir Musaev
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Valentina Stanley
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia
| | - Abduljabbar Alshenqiti
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 1211, Saudi Arabia
| | - Fatma Mujgan Sonmez
- Karadeniz Technical University, Faculty of Medicine, Department of Child Neurology, Retired Lecturer, Trabzon 61080, Turkey
| | - Nadia Saqati
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 1211, Saudi Arabia
| | - Hamad Alzaidan
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 1211, Saudi Arabia
| | | | - Futwan Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital and Research Center, PO Box 245, Riyadh 11211, Saudi Arabia
| | - Joseph G Gleeson
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh 12371, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
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26
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Identification of novel loci for pediatric cholestatic liver disease defined by KIF12, PPM1F, USP53, LSR, and WDR83OS pathogenic variants. Genet Med 2018; 21:1164-1172. [PMID: 30250217 DOI: 10.1038/s41436-018-0288-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 08/17/2018] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Genetic testing in pediatric cholestasis can be very informative but genetic causes have not been fully characterized. METHODS Exome sequencing and positional mapping in seven families with cholestatic liver disease and negative clinical testing for known disease genes. RESULTS KIF12, which encodes a microtubule motor protein with a tentative role in cell polarity, was found to harbor three homozygous likely deleterious variants in three families with sclerosing cholangitis. KIF12 expression is dependent on HNF-1β, deficiency which is known to cause bile duct dysmorphogenesis associated with loss of KIF12 expression. In another extended family, we mapped an apparently novel syndrome of sclerosing cholangitis, short stature, hypothyroidism, and abnormal tongue pigmentation in two cousins to a homozygous variant in PPM1F (POPX2), a regulator of kinesin-mediated ciliary transport. In the fifth family, a syndrome of normal gamma glutamyltransferase (GGT) cholestasis and hearing loss was found to segregate with a homozygous truncating variant in USP53, which encodes an interactor with TJP2. In the sixth family, we mapped a novel syndrome of transient neonatal cholestasis, intellectual disability, and short stature to a homozygous variant in LSR, an important regulator of liver development. In the last family of three affected siblings, a novel syndrome of intractable itching, hypercholanemia, short stature, and intellectual disability was mapped to a single locus that contains a homozygous truncating variant in WDR83OS (C19orf56), known to interact with ATP13A2 and BSEP. CONCLUSION Our results expand the genetic heterogeneity of pediatric cholestatic liver disease and highlight the vulnerability of bile homeostasis to a wide range of molecular perturbations.
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27
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Maddirevula S, Alzahrani F, Al-Owain M, Al Muhaizea MA, Kayyali HR, AlHashem A, Rahbeeni Z, Al-Otaibi M, Alzaidan HI, Balobaid A, El Khashab HY, Bubshait DK, Faden M, Yamani SA, Dabbagh O, Al-Mureikhi M, Jasser AA, Alsaif HS, Alluhaydan I, Seidahmed MZ, Alabbasi BH, Almogarri I, Kurdi W, Akleh H, Qari A, Al Tala SM, Alhomaidi S, Kentab AY, Salih MA, Chedrawi A, Alameer S, Tabarki B, Shamseldin HE, Patel N, Ibrahim N, Abdulwahab F, Samira M, Goljan E, Abouelhoda M, Meyer BF, Hashem M, Shaheen R, AlShahwan S, Alfadhel M, Ben-Omran T, Al-Qattan MM, Monies D, Alkuraya FS. Autozygome and high throughput confirmation of disease genes candidacy. Genet Med 2018; 21:736-742. [PMID: 30237576 PMCID: PMC6752307 DOI: 10.1038/s41436-018-0138-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/05/2018] [Indexed: 02/06/2023] Open
Abstract
Purpose Establishing links between Mendelian phenotypes and genes enables the proper interpretation of variants therein. Autozygome, a rich source of homozygous variants, has been successfully utilized for the high throughput identification of novel autosomal recessive disease genes. Here, we highlight the utility of the autozygome for the high throughput confirmation of previously published tentative links to diseases. Methods Autozygome and exome analysis of patients with suspected Mendelian phenotypes. All variants were classified according to the American College of Medical Genetics and Genomics guidelines. Results We highlight 30 published candidate genes (ACTL6B, ADAM22, AGTPBP1, APC, C12orf4, C3orf17 (NEPRO), CENPF, CNPY3, COL27A1, DMBX1, FUT8, GOLGA2, KIAA0556, LENG8, MCIDAS, MTMR9, MYH11, QRSL1, RUBCN, SLC25A42, SLC9A1, TBXT, TFG, THUMPD1, TRAF3IP2, UFC1, UFM1, WDR81, XRCC2, ZAK) in which we identified homozygous likely deleterious variants in patients with compatible phenotypes. We also identified homozygous likely deleterious variants in 18 published candidate genes (ABCA2, ARL6IP1, ATP8A2, CDK9, CNKSR1, DGAT1, DMXL2, GEMIN4, HCN2, HCRT, MYO9A, PARS2, PLOD3, PREPL, SCLT1, STX3, TXNRD2, WIPI2) although the associated phenotypes are sufficiently different from the original reports that they represent phenotypic expansion or potentially distinct allelic disorders. Conclusions Our results should facilitate the timely relabeling of these candidate disease genes in relevant databases to improve the yield of clinical genomic sequencing.
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Affiliation(s)
- Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Mohammad A Al Muhaizea
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Husam R Kayyali
- Department of Pediatrics, King Faisal Specialist hospital and Research Center, Jeddah, Saudi Arabia
| | - Amal AlHashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Zuhair Rahbeeni
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maha Al-Otaibi
- Genetic Unit, Children's Hospital, King Saud Medical City, Riyadh, Saudi Arabia
| | - Hamad I Alzaidan
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Ameera Balobaid
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Heba Y El Khashab
- Department of Pediatrics, Children's Hospital, Ain Shams University, Cairo, Egypt.,Department of Pediatrics, Dr. Suliman Al Habib Medical Group, Riyadh, Saudi Arabia
| | - Dalal K Bubshait
- Department of Pediatrics, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Maha Faden
- Genetic Unit, Children's Hospital, King Saud Medical City, Riyadh, Saudi Arabia
| | - Suad Al Yamani
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Omar Dabbagh
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mariam Al-Mureikhi
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Doha, Qatar
| | - Abdulla Al Jasser
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Iram Alluhaydan
- Genetics Division, Department of Pediatrics, King Saud Bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | | | | | - Ibrahim Almogarri
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Wesam Kurdi
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Neuroscience, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hana Akleh
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Alya Qari
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Saeed M Al Tala
- Department of Pediatrics, Armed Forces Hospital SR, Khamis Mushayt, Saudi Arabia
| | - Suzan Alhomaidi
- Genetic Unit, Children's Hospital, King Saud Medical City, Riyadh, Saudi Arabia
| | - Amal Y Kentab
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Aziza Chedrawi
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Seham Alameer
- Department of pediatrics, King Abdulaziz Medical City, Jeddah, Saudi Arabia
| | - Brahim Tabarki
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Menasria Samira
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ewa Goljan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Saad AlShahwan
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- Medical Genetic Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Tawfeg Ben-Omran
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Doha, Qatar
| | - Mohammad M Al-Qattan
- Department of Surgery, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia. .,Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia. .,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
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28
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Molecular genetic study of Calpainopathy in Iran. Gene 2018; 677:259-265. [PMID: 30056071 DOI: 10.1016/j.gene.2018.07.067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/18/2018] [Accepted: 07/26/2018] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Calpainopathy is an autosomal recessive form of limb girdle muscular dystrophies (LGMDs) caused by mutations in the CAPN3 gene. CAPN3 is a Ca2+-dependent cystein protease consisting of 821 amino acids. LGMD is a highly heterogeneous disorder and mutation identification of this disease by Sanger sequencing of all genes is expensive and time consuming. Using autozygosity mapping is an effective approach to address this issue. METHODS We used two sets of multiplex STR (Short tandem repeat) markers linked to CAPN3, DYSF, SGCA, SGCB, SGCG, SGCD genes following sequencing of the CAPN3 gene. In silico analysis and mutation detection in one hundred ethnically matched healthy individuals were carried out to determine the pathogenicity of novel mutations. Sequence variant interpretation was performed using the American College of Medical Genetics and Genomics (ACMG) guideline. RESULTS Sixteen out of 50 families linked to the CAPN3 gene. In this study, mutations were found in 14 out of 16 families including 4 novel (c.1894A > T, c.567delG, c.2254-2256delAAC, and c.2373C > T) and 9 previously reported mutations consisting of 5 missense (c.2105C > T, c.2243G > A, c.1714C > T, c.291C > A, c.956C > T), 3 splice site (c.2380 + 2 T > G, c.946-2A > G, c.380G > A), and one indel (c.2257delinsAA) mutations. DISCUSSION The c.2105C > T was found to be the most frequent mutation in this study. The results of this study revealed that most cases with splicing, frame shift and nonsense mutations experienced more severe clinical manifestations. Nonetheless, this should be confirmed by further studies on larger sample size.
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Patel N, Khan AO, Alsahli S, Abdel-Salam G, Nowilaty SR, Mansour AM, Nabil A, Al-Owain M, Sogati S, Salih MA, Kamal AM, Alsharif H, Alsaif HS, Alzahrani SS, Abdulwahab F, Ibrahim N, Hashem M, Faquih T, Shah ZA, Abouelhoda M, Monies D, Dasouki M, Shaheen R, Wakil SM, Aldahmesh MA, Alkuraya FS. Genetic investigation of 93 families with microphthalmia or posterior microphthalmos. Clin Genet 2018; 93:1210-1222. [PMID: 29450879 DOI: 10.1111/cge.13239] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 01/24/2023]
Abstract
Microphthalmia is a developmental eye defect that is highly variable in severity and in its potential for systemic association. Despite the discovery of many disease genes in microphthalmia, at least 50% of patients remain undiagnosed genetically. Here, we describe a cohort of 147 patients (93 families) from our highly consanguineous population with various forms of microphthalmia (including the distinct entity of posterior microphthalmos) that were investigated using a next-generation sequencing multi-gene panel (i-panel) as well as whole exome sequencing and molecular karyotyping. A potentially causal mutation was identified in the majority of the cohort with microphthalmia (61%) and posterior microphthalmos (82%). The identified mutations (55 point mutations, 15 of which are novel) spanned 24 known disease genes, some of which have not or only very rarely been linked to microphthalmia (PAX6, SLC18A2, DSC3 and CNKSR1). Our study has also identified interesting candidate variants in 2 genes that have not been linked to human diseases (MYO10 and ZNF219), which we present here as novel candidates for microphthalmia. In addition to revealing novel phenotypic aspects of microphthalmia, this study expands its allelic and locus heterogeneity and highlights the need for expanded testing of patients with this condition.
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Affiliation(s)
- N Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - A O Khan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - S Alsahli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | | | - S R Nowilaty
- Vitreo-retinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - A M Mansour
- Department of Ophthalmology, American University of Beirut, Beirut, Lebanon
| | - A Nabil
- Human Genetics Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - M Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - S Sogati
- Department of Medical Genetics, King Fahad General Hospital, Jeddah, Saudi Arabia
| | - M A Salih
- Division of Pediatrics Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - A M Kamal
- Department of Ophthalmology, Cairo University, Cairo, Egypt
| | - H Alsharif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - H S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - S S Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - F Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - N Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - M Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - T Faquih
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Z A Shah
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - M Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - D Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - M Dasouki
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - R Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - S M Wakil
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - M A Aldahmesh
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - F S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Ceballos FC, Joshi PK, Clark DW, Ramsay M, Wilson JF. Runs of homozygosity: windows into population history and trait architecture. Nat Rev Genet 2018; 19:220-234. [PMID: 29335644 DOI: 10.1038/nrg.2017.109] [Citation(s) in RCA: 361] [Impact Index Per Article: 60.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Long runs of homozygosity (ROH) arise when identical haplotypes are inherited from each parent and thus a long tract of genotypes is homozygous. Cousin marriage or inbreeding gives rise to such autozygosity; however, genome-wide data reveal that ROH are universally common in human genomes even among outbred individuals. The number and length of ROH reflect individual demographic history, while the homozygosity burden can be used to investigate the genetic architecture of complex disease. We discuss how to identify ROH in genome-wide microarray and sequence data, their distribution in human populations and their application to the understanding of inbreeding depression and disease risk.
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Affiliation(s)
- Francisco C Ceballos
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, South Africa.,Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Peter K Joshi
- Centre for Global Health Research, Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, UK
| | - David W Clark
- Centre for Global Health Research, Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, UK
| | - Michèle Ramsay
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, Johannesburg, South Africa.,Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Braamfontein 2000, Johannesburg, South Africa
| | - James F Wilson
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK.,Centre for Global Health Research, Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, UK
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31
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Shamseldin HE, Alasmari A, Salih MA, Samman MM, Mian SA, Alshidi T, Ibrahim N, Hashem M, Faqeih E, Al-Mohanna F, Alkuraya FS. A null mutation in MICU2 causes abnormal mitochondrial calcium homeostasis and a severe neurodevelopmental disorder. Brain 2017; 140:2806-2813. [PMID: 29053821 DOI: 10.1093/brain/awx237] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 08/05/2017] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial calcium homeostasis is a tightly controlled process that is required for a variety of cellular functions. The mitochondrial calcium uniporter complex plays a critical role in this process. MICU2 is a major component of the mitochondrial calcium uniporter complex and its deficiency has been shown to impair mitochondrial calcium [Ca2+]m homeostasis although the exact mechanism remains unclear. We used exome sequencing, positional mapping, and functional characterization of MICU2 deficiency to investigate the role of MICU2 in calcium homeostasis. Using combined autozygome/exome analysis, a homozygous truncating mutation in MICU2 was found to fully segregate with a neurodevelopmental disorder in the form of severe cognitive impairment, spasticity, and white matter involvement in a multiplex consanguineous family. Patient-derived MICU2-deficient cells displayed impaired [Ca2+]m homeostasis, with associated increase in mitochondrial sensitivity to oxidative stress, and abnormal regulation of inner mitochondrial membrane potential. This is the first demonstration of MICU2 deficiency in humans, which we suggest causes a distinct neurodevelopmental phenotype secondary to impaired mitochondrial calcium uniporter-mediated regulation of intracellular calcium homeostasis.
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Affiliation(s)
- Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ali Alasmari
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Mohammed A Salih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Manar M Samman
- Department of Pathology and Clinical Laboratory Medicine, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Shahid A Mian
- National Neuroscience Institute Research Unit, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Tarfa Alshidi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Futwan Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
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Moawia A, Shaheen R, Rasool S, Waseem SS, Ewida N, Budde B, Kawalia A, Motameny S, Khan K, Fatima A, Jameel M, Ullah F, Akram T, Ali Z, Abdullah U, Irshad S, Höhne W, Noegel AA, Al-Owain M, Hörtnagel K, Stöbe P, Baig SM, Nürnberg P, Alkuraya FS, Hahn A, Hussain MS. Mutations of KIF14 cause primary microcephaly by impairing cytokinesis. Ann Neurol 2017; 82:562-577. [PMID: 28892560 DOI: 10.1002/ana.25044] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Autosomal recessive primary microcephaly (MCPH) is a rare condition characterized by a reduced cerebral cortex accompanied with intellectual disability. Mutations in 17 genes have been shown to cause this phenotype. Recently, mutations in CIT, encoding CRIK (citron rho-interacting kinase)-a component of the central spindle matrix-were added. We aimed at identifying novel MCPH-associated genes and exploring their functional role in pathogenesis. METHODS Linkage analysis and whole exome sequencing were performed in consanguineous and nonconsanguineous MCPH families to identify disease-causing variants. Functional consequences were investigated by RNA studies and on the cellular level using immunofluorescence and microscopy. RESULTS We identified homozygous mutations in KIF14 (NM_014875.2;c.263T>A;pLeu88*, c.2480_2482delTTG; p.Val827del, and c.4071G>A;p.Gln1357=) as the likely cause in 3 MCPH families. Furthermore, in a patient presenting with a severe form of primary microcephaly and short stature, we identified compound heterozygous missense mutations in KIF14 (NM_014875.2;c.2545C>G;p.His849Asp and c.3662G>T;p.Gly1221Val). Three of the 5 identified mutations impaired splicing, and 2 resulted in a truncated protein. Intriguingly, Kif14 knockout mice also showed primary microcephaly. Human kinesin-like protein KIF14, a microtubule motor protein, localizes at the midbody to finalize cytokinesis by interacting with CRIK. We found impaired localization of both KIF14 and CRIK at the midbody in patient-derived fibroblasts. Furthermore, we observed a large number of binucleated and apoptotic cells-signs of failed cytokinesis that we also observed in experimentally KIF14-depleted cells. INTERPRETATION Our data corroborate the role of an impaired cytokinesis in the etiology of primary and syndromic microcephaly, as has been proposed by recent findings on CIT mutations. Ann Neurol 2017;82:562-577.
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Affiliation(s)
- Abubakar Moawia
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany.,Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sajida Rasool
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Biochemistry and Biotechnology, Quaid-e-Azam Campus, University of the Punjab, Lahore, Pakistan
| | - Syeda Seema Waseem
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany.,Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Birgit Budde
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Amit Kawalia
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Susanne Motameny
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Kamal Khan
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Ambrin Fatima
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Muhammad Jameel
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Farid Ullah
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Talia Akram
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Zafar Ali
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Uzma Abdullah
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Saba Irshad
- Institute of Biochemistry and Biotechnology, Quaid-e-Azam Campus, University of the Punjab, Lahore, Pakistan
| | - Wolfgang Höhne
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Angelika Anna Noegel
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital, Riyadh, Saudi Arabia
| | | | - Petra Stöbe
- Center for Genomics and Transcriptomics, Tübingen, Germany
| | - Shahid Mahmood Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Fowzan Sami Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Andreas Hahn
- Department of Child Neurology, University of Giessen, Giessen, Germany
| | - Muhammad Sajid Hussain
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
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Van De Weghe JC, Rusterholz TD, Latour B, Grout ME, Aldinger KA, Shaheen R, Dempsey JC, Maddirevula S, Cheng YHH, Phelps IG, Gesemann M, Goel H, Birk OS, Alanzi T, Rawashdeh R, Khan AO, Bamshad MJ, Nickerson DA, Neuhauss SC, Dobyns WB, Alkuraya FS, Roepman R, Bachmann-Gagescu R, Doherty D, Doherty D. Mutations in ARMC9, which Encodes a Basal Body Protein, Cause Joubert Syndrome in Humans and Ciliopathy Phenotypes in Zebrafish. Am J Hum Genet 2017. [PMID: 28625504 DOI: 10.1016/j.ajhg.2017.05.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterized by hypotonia, ataxia, abnormal eye movements, and variable cognitive impairment. It is defined by a distinctive brain malformation known as the "molar tooth sign" on axial MRI. Subsets of affected individuals have malformations such as coloboma, polydactyly, and encephalocele, as well as progressive retinal dystrophy, fibrocystic kidney disease, and liver fibrosis. More than 35 genes have been associated with JS, but in a subset of families the genetic cause remains unknown. All of the gene products localize in and around the primary cilium, making JS a canonical ciliopathy. Ciliopathies are unified by their overlapping clinical features and underlying mechanisms involving ciliary dysfunction. In this work, we identify biallelic rare, predicted-deleterious ARMC9 variants (stop-gain, missense, splice-site, and single-exon deletion) in 11 individuals with JS from 8 families, accounting for approximately 1% of the disorder. The associated phenotypes range from isolated neurological involvement to JS with retinal dystrophy, additional brain abnormalities (e.g., heterotopia, Dandy-Walker malformation), pituitary insufficiency, and/or synpolydactyly. We show that ARMC9 localizes to the basal body of the cilium and is upregulated during ciliogenesis. Typical ciliopathy phenotypes (curved body shape, retinal dystrophy, coloboma, and decreased cilia) in a CRISPR/Cas9-engineered zebrafish mutant model provide additional support for ARMC9 as a ciliopathy-associated gene. Identifying ARMC9 mutations as a cause of JS takes us one step closer to a full genetic understanding of this important disorder and enables future functional work to define the central biological mechanisms underlying JS and other ciliopathies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Dan Doherty
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA.
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Anazi S, Maddirevula S, Faqeih E, Alsedairy H, Alzahrani F, Shamseldin HE, Patel N, Hashem M, Ibrahim N, Abdulwahab F, Ewida N, Alsaif HS, Al Sharif H, Alamoudi W, Kentab A, Bashiri FA, Alnaser M, AlWadei AH, Alfadhel M, Eyaid W, Hashem A, Al Asmari A, Saleh MM, AlSaman A, Alhasan KA, Alsughayir M, Al Shammari M, Mahmoud A, Al-Hassnan ZN, Al-Husain M, Osama Khalil R, Abd El Meguid N, Masri A, Ali R, Ben-Omran T, El Fishway P, Hashish A, Ercan Sencicek A, State M, Alazami AM, Salih MA, Altassan N, Arold ST, Abouelhoda M, Wakil SM, Monies D, Shaheen R, Alkuraya FS. Clinical genomics expands the morbid genome of intellectual disability and offers a high diagnostic yield. Mol Psychiatry 2017; 22:615-624. [PMID: 27431290 DOI: 10.1038/mp.2016.113] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 12/13/2022]
Abstract
Intellectual disability (ID) is a measurable phenotypic consequence of genetic and environmental factors. In this study, we prospectively assessed the diagnostic yield of genomic tools (molecular karyotyping, multi-gene panel and exome sequencing) in a cohort of 337 ID subjects as a first-tier test and compared it with a standard clinical evaluation performed in parallel. Standard clinical evaluation suggested a diagnosis in 16% of cases (54/337) but only 70% of these (38/54) were subsequently confirmed. On the other hand, the genomic approach revealed a likely diagnosis in 58% (n=196). These included copy number variants in 14% (n=54, 15% are novel), and point mutations revealed by multi-gene panel and exome sequencing in the remaining 43% (1% were found to have Fragile-X). The identified point mutations were mostly recessive (n=117, 81%), consistent with the high consanguinity of the study cohort, but also X-linked (n=8, 6%) and de novo dominant (n=19, 13%). When applied directly on all cases with negative molecular karyotyping, the diagnostic yield of exome sequencing was 60% (77/129). Exome sequencing also identified likely pathogenic variants in three novel candidate genes (DENND5A, NEMF and DNHD1) each of which harbored independent homozygous mutations in patients with overlapping phenotypes. In addition, exome sequencing revealed de novo and recessive variants in 32 genes (MAMDC2, TUBAL3, CPNE6, KLHL24, USP2, PIP5K1A, UBE4A, TP53TG5, ATOH1, C16ORF90, SLC39A14, TRERF1, RGL1, CDH11, SYDE2, HIRA, FEZF2, PROCA1, PIANP, PLK2, QRFPR, AP3B2, NUDT2, UFC1, BTN3A2, TADA1, ARFGEF3, FAM160B1, ZMYM5, SLC45A1, ARHGAP33 and CAPS2), which we highlight as potential candidates on the basis of several lines of evidence, and one of these genes (SLC39A14) was biallelically inactivated in a potentially treatable form of hypermanganesemia and neurodegeneration. Finally, likely causal variants in previously published candidate genes were identified (ASTN1, HELZ, THOC6, WDR45B, ADRA2B and CLIP1), thus supporting their involvement in ID pathogenesis. Our results expand the morbid genome of ID and support the adoption of genomics as a first-tier test for individuals with ID.
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Affiliation(s)
- S Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - S Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - E Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - H Alsedairy
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - F Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - H E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - N Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - M Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - N Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - F Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - N Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - H S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - H Al Sharif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - W Alamoudi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - A Kentab
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - F A Bashiri
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - M Alnaser
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - A H AlWadei
- Pediatric Neurology Department, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - M Alfadhel
- Department of Pediatrics, King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - W Eyaid
- Department of Pediatrics, King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - A Hashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - A Al Asmari
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - M M Saleh
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - A AlSaman
- Pediatric Neurology Department, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - K A Alhasan
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - M Alsughayir
- Department of Psychiatry, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - M Al Shammari
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - A Mahmoud
- Pediatric Neurology Department, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Z N Al-Hassnan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - M Al-Husain
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - R Osama Khalil
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA.,National Research Center, Cairo, Egypt
| | | | - A Masri
- Department of Pediatrics, Faculty of Medicine, The University of Jordan, Amman, Jordan
| | - R Ali
- Clinical & Metabolic Genetics, Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - T Ben-Omran
- Clinical & Metabolic Genetics, Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - P El Fishway
- Department of Neurosurgery, Program on Neurogenetics, Yale University School of Medicine, New Haven, CT, USA
| | - A Hashish
- National Research Center, Cairo, Egypt
| | - A Ercan Sencicek
- Department of Neurosurgery, Program on Neurogenetics, Yale University School of Medicine, New Haven, CT, USA
| | - M State
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - A M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - M A Salih
- Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - N Altassan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - S T Arold
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal, Saudi Arabia
| | - M Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - S M Wakil
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - D Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - R Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - F S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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35
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Shaheen R, Szymanska K, Basu B, Patel N, Ewida N, Faqeih E, Al Hashem A, Derar N, Alsharif H, Aldahmesh MA, Alazami AM, Hashem M, Ibrahim N, Abdulwahab FM, Sonbul R, Alkuraya H, Alnemer M, Al Tala S, Al-Husain M, Morsy H, Seidahmed MZ, Meriki N, Al-Owain M, AlShahwan S, Tabarki B, Salih MA, Faquih T, El-Kalioby M, Ueffing M, Boldt K, Logan CV, Parry DA, Al Tassan N, Monies D, Megarbane A, Abouelhoda M, Halees A, Johnson CA, Alkuraya FS. Characterizing the morbid genome of ciliopathies. Genome Biol 2016; 17:242. [PMID: 27894351 PMCID: PMC5126998 DOI: 10.1186/s13059-016-1099-5] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/07/2016] [Indexed: 11/25/2022] Open
Abstract
Background Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. Results We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their “mutation load” beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. Conclusions Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies. Electronic supplementary material The online version of this article (doi:10.1186/s13059-016-1099-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Katarzyna Szymanska
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - Basudha Basu
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Amal Al Hashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Nada Derar
- Department of Pediatrics, Division of Medical Genetics, Stanford University, Stanford, CA, USA
| | - Hadeel Alsharif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohammed A Aldahmesh
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Anas M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous M Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rawda Sonbul
- Department of Pediatrics, Qatif Central Hospital, Qatif, Saudi Arabia
| | - Hisham Alkuraya
- Department of Ophthalmology, Specialized Medical Center Hospital, Riyadh, Saudi Arabia
| | - Maha Alnemer
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Saeed Al Tala
- Department of Pediatric, Genetic Unit, Armed Forces Hospital Southern Region, Khamis Mushayt, Saudi Arabia
| | - Muneera Al-Husain
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Heba Morsy
- Human Genetics Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | | | - Neama Meriki
- Department of Obstetrics and Gynecology, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Saad AlShahwan
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | | | - Tariq Faquih
- Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mohamed El-Kalioby
- Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Bioanalytics, Center for Ophthalmology, Eberhard-Karls University Tübingen, 72076, Tübingen, Germany
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Bioanalytics, Center for Ophthalmology, Eberhard-Karls University Tübingen, 72076, Tübingen, Germany
| | - Clare V Logan
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - David A Parry
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - Nada Al Tassan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | | | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Anason Halees
- Health Information Technology Affairs, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Colin A Johnson
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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36
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Patel N, Anand D, Monies D, Maddirevula S, Khan AO, Algoufi T, Alowain M, Faqeih E, Alshammari M, Qudair A, Alsharif H, Aljubran F, Alsaif HS, Ibrahim N, Abdulwahab FM, Hashem M, Alsedairy H, Aldahmesh MA, Lachke SA, Alkuraya FS. Novel phenotypes and loci identified through clinical genomics approaches to pediatric cataract. Hum Genet 2016; 136:205-225. [PMID: 27878435 DOI: 10.1007/s00439-016-1747-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/16/2016] [Indexed: 01/17/2023]
Abstract
Pediatric cataract is highly heterogeneous clinically and etiologically. While mostly isolated, cataract can be part of many multisystem disorders, further complicating the diagnostic process. In this study, we applied genomic tools in the form of a multi-gene panel as well as whole-exome sequencing on unselected cohort of pediatric cataract (166 patients from 74 families). Mutations in previously reported cataract genes were identified in 58% for a total of 43 mutations, including 15 that are novel. GEMIN4 was independently mutated in families with a syndrome of cataract, global developmental delay with or without renal involvement. We also highlight a recognizable syndrome that resembles galactosemia (a fulminant infantile liver disease with cataract) caused by biallelic mutations in CYP51A1. A founder mutation in RIC1 (KIAA1432) was identified in patients with cataract, brain atrophy, microcephaly with or without cleft lip and palate. For non-syndromic pediatric cataract, we map a novel locus in a multiplex consanguineous family on 4p15.32 where exome sequencing revealed a homozygous truncating mutation in TAPT1. We report two further candidates that are biallelically inactivated each in a single cataract family: TAF1A (cataract with global developmental delay) and WDR87 (non-syndromic cataract). In addition to positional mapping data, we use iSyTE developmental lens expression and gene-network analysis to corroborate the proposed link between the novel candidate genes and cataract. Our study expands the phenotypic, allelic and locus heterogeneity of pediatric cataract. The high diagnostic yield of clinical genomics supports the adoption of this approach in this patient group.
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Affiliation(s)
- Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Arif O Khan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Talal Algoufi
- Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohammed Alowain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatrics, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Muneera Alshammari
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed Qudair
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Hadeel Alsharif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatimah Aljubran
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous M Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Haifa Alsedairy
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohammed A Aldahmesh
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19716, USA
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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37
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Shamseldin HE, Maddirevula S, Faqeih E, Ibrahim N, Hashem M, Shaheen R, Alkuraya FS. Increasing the sensitivity of clinical exome sequencing through improved filtration strategy. Genet Med 2016; 19:593-598. [PMID: 27711071 DOI: 10.1038/gim.2016.155] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/24/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Clinical exome sequencing (CES) has greatly improved the diagnostic process for individuals with suspected genetic disorders. However, the majority remains undiagnosed after CES. Although understanding potential reasons for this limited sensitivity is critical for improving the delivery of clinical genomics, research in this area has been limited. MATERIALS AND METHODS We first calculated the theoretical maximum sensitivity of CES by analyzing >100 families in whom a Mendelian phenotype is mapped to a single locus. We then tested the hypothesis that positional mapping can limit the search space and thereby facilitate variant interpretation by reanalyzing 33 families with "negative" CES and applying positional mapping. RESULTS We found that >95% of families who map to a single locus harbored genic (as opposed to intergenic) variants that are potentially identifiable by CES. Our reanalysis of "negative" CES revealed likely causal variants in the majority (88%). Several of these solved cases have undergone negative whole-genome sequencing. CONCLUSION The discrepancy between the theoretical maximum and the actual clinical sensitivity of CES is primarily in the variant filtration rather than the variant capture and sequencing phase. The solution to negative CES is not necessarily in expanding the coverage but rather in devising approaches that improve variant filtration. We suggest that positional mapping is one such approach.Genet Med advance online publication 06 October 2016.
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Affiliation(s)
- Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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38
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Shamseldin HE, Maddirevula S, Nabil A, Al-Fadhil S, Al Tala S, Alkuraya FS. Joint laxity in homozygotes for severePOU1F1mutations. Am J Med Genet A 2016; 170:3356-3358. [DOI: 10.1002/ajmg.a.37941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/08/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Hanan E. Shamseldin
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | - Amira Nabil
- Department of Human Genetics; Medical Research Institute; Alexandria University; Alexandria Egypt
| | - Saeed Al-Fadhil
- Department of Pediatrics; Armed Forces Hospitals Southern Region; Khamis Mushayt Saudi Arabia
| | - Saeed Al Tala
- Department of Pediatrics; Armed Forces Hospitals Southern Region; Khamis Mushayt Saudi Arabia
| | - Fowzan S. Alkuraya
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
- Department of Anatomy and Cell Biology; College of Medicine; Alfaisal University; Riyadh Saudi Arabia
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39
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Mutations in CIT, encoding citron rho-interacting serine/threonine kinase, cause severe primary microcephaly in humans. Hum Genet 2016; 135:1191-7. [PMID: 27503289 DOI: 10.1007/s00439-016-1722-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 08/02/2016] [Indexed: 01/08/2023]
Abstract
Primary microcephaly is a clinical phenotype in which the head circumference is significantly reduced at birth due to abnormal brain development, primarily at the cortical level. Despite the marked genetic heterogeneity, most primary microcephaly-linked genes converge on mitosis regulation. Two consanguineous families segregating the phenotype of severe primary microcephaly, spasticity and failure to thrive had overlapping autozygomes in which exome sequencing identified homozygous splicing variants in CIT that segregate with the phenotype within each family. CIT encodes citron, an effector of the Rho signaling that is required for cytokinesis specifically in proliferating neuroprogenitors, as well as for postnatal brain development. In agreement with the critical role assigned to the kinase domain in effecting these biological roles, we show that both splicing variants predict variable disruption of this domain. The striking phenotypic overlap between CIT-mutated individuals and the knockout mice and rats that are specifically deficient in the kinase domain supports the proposed causal link between CIT mutation and primary microcephaly in humans.
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40
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ANKS3 is mutated in a family with autosomal recessive laterality defect. Hum Genet 2016; 135:1233-1239. [DOI: 10.1007/s00439-016-1712-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/09/2016] [Indexed: 10/21/2022]
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41
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Clinical genomics can facilitate countrywide estimation of autosomal recessive disease burden. Genet Med 2016; 18:1244-1249. [DOI: 10.1038/gim.2016.37] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/10/2016] [Indexed: 01/02/2023] Open
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42
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Anazi S, Shamseldin HE, AlNaqeb D, Abouelhoda M, Monies D, Salih MA, Al-Rubeaan K, Alkuraya FS. A null mutation in TNIK defines a novel locus for intellectual disability. Hum Genet 2016; 135:773-8. [PMID: 27106596 DOI: 10.1007/s00439-016-1671-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/09/2016] [Indexed: 10/21/2022]
Abstract
Intellectual disability (ID) is one of the most common disabilities and, although many genes have been implicated in its etiology, the genetic heterogeneity of ID continues to expand. The purpose of the study was to describe a novel autosomal recessive non-syndromic ID locus. Autozygome and linkage analysis, and exome sequencing followed by RNA and protein analysis of the candidate disease gene were performed. We describe two multiplex consanguineous families with non-syndromic ID phenotype, which maps to a critical linkage locus on 3q26. Exome sequencing of the index in each family revealed the same homozygous truncating mutation in TNIK that results in complete loss of the protein. TNIK is a kinase with a well-established role in dendrite development and synaptic transmission. The phenotype we observe in human patients who lack TNIK is consistent with the previously published Tnik (-/-) phenotype in the murine model. Our data strongly implicate TNIK deficiency in the causation of ID in humans.
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Affiliation(s)
- Shams Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Dhekra AlNaqeb
- University Diabetes Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Al-Rubeaan
- University Diabetes Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia. .,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
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43
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Shaheen R, Anazi S, Ben-Omran T, Seidahmed M, Caddle L, Palmer K, Ali R, Alshidi T, Hagos S, Goodwin L, Hashem M, Wakil S, Abouelhoda M, Colak D, Murray S, Alkuraya F. Mutations in SMG9, Encoding an Essential Component of Nonsense-Mediated Decay Machinery, Cause a Multiple Congenital Anomaly Syndrome in Humans and Mice. Am J Hum Genet 2016; 98:643-52. [PMID: 27018474 DOI: 10.1016/j.ajhg.2016.02.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/11/2016] [Indexed: 12/28/2022] Open
Abstract
Nonsense-mediated decay (NMD) is an important process that is best known for degrading transcripts that contain premature stop codons (PTCs) to mitigate their potentially harmful consequences, although its regulatory role encompasses other classes of transcripts as well. Despite the critical role of NMD at the cellular level, our knowledge about the consequences of deficiency of its components at the organismal level is largely limited to model organisms. In this study, we report two consanguineous families in which a similar pattern of congenital anomalies was found to be most likely caused by homozygous loss-of-function mutations in SMG9, encoding an essential component of the SURF complex that generates phospho-UPF1, the single most important step in NMD. By knocking out Smg9 in mice via CRISPR/Cas9, we were able to recapitulate the major features of the SMG9-related multiple congenital anomaly syndrome we observed in humans. Surprisingly, human cells devoid of SMG9 do not appear to have reduction of PTC-containing transcripts but do display global transcriptional dysregulation. We conclude that SMG9 is required for normal human and murine development, most likely through a transcriptional regulatory role, the precise nature of which remains to be determined.
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44
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Shamseldin H, Faqeih E, Alasmari A, Zaki M, Gleeson J, Alkuraya F. Mutations in UNC80, Encoding Part of the UNC79-UNC80-NALCN Channel Complex, Cause Autosomal-Recessive Severe Infantile Encephalopathy. Am J Hum Genet 2016; 98:210-5. [PMID: 26708753 DOI: 10.1016/j.ajhg.2015.11.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/06/2015] [Indexed: 10/22/2022] Open
Abstract
Brain channelopathies represent a growing class of brain disorders that usually result in paroxysmal disorders, although their role in other neurological phenotypes, including the recently described NALCN-related infantile encephalopathy, is increasingly recognized. In three Saudi Arabian families and one Egyptian family all affected by a remarkably similar phenotype (infantile encephalopathy and largely normal brain MRI) to that of NALCN-related infantile encephalopathy, we identified a locus on 2q34 in which whole-exome sequencing revealed three, including two apparently loss-of-function, recessive mutations in UNC80. UNC80 encodes a large protein that is necessary for the stability and function of NALCN and for bridging NALCN to UNC79 to form a functional complex. Our results expand the clinical relevance of the UNC79-UNC80-NALCN channel complex.
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45
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Shamseldin HE, Bennett AH, Alfadhel M, Gupta V, Alkuraya FS. GOLGA2, encoding a master regulator of golgi apparatus, is mutated in a patient with a neuromuscular disorder. Hum Genet 2016; 135:245-251. [PMID: 26742501 DOI: 10.1007/s00439-015-1632-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/25/2015] [Indexed: 01/21/2023]
Abstract
Golgi apparatus (GA) is a membrane-bound organelle that serves a multitude of critical cellular functions including protein secretion and sorting, and cellular polarity. Many Mendelian diseases are caused by mutations in genes encoding various components of GA. GOLGA2 encodes GM130, a necessary component for the assembly of GA as a single complex, and its deficiency has been found to result in severe cellular phenotypes. We describe the first human patient with a homozygous apparently loss of function mutation in GOLGA2. The phenotype is a neuromuscular disorder characterized by developmental delay, seizures, progressive microcephaly, and muscular dystrophy. Knockdown of golga2 in zebrafish resulted in severe skeletal muscle disorganization and microcephaly recapitulating loss of function human phenotype. Our data suggest an important developmental role of GM130 in humans and zebrafish.
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Affiliation(s)
- Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Alexis H Bennett
- Division of Genetics, Brigham and Women's Hospital and Department of Genetics, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Majid Alfadhel
- Genetics Division, Department of Pediatrics, King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Vandana Gupta
- Division of Genetics, Brigham and Women's Hospital and Department of Genetics, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Shaheen R, Patel N, Shamseldin H, Alzahrani F, Al-Yamany R, ALMoisheer A, Ewida N, Anazi S, Alnemer M, Elsheikh M, Alfaleh K, Alshammari M, Alhashem A, Alangari AA, Salih MA, Kircher M, Daza RM, Ibrahim N, Wakil SM, Alaqeel A, Altowaijri I, Shendure J, Al-Habib A, Faqieh E, Alkuraya FS. Accelerating matchmaking of novel dysmorphology syndromes through clinical and genomic characterization of a large cohort. Genet Med 2015; 18:686-95. [PMID: 26633546 DOI: 10.1038/gim.2015.147] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/03/2015] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Dysmorphology syndromes are among the most common referrals to clinical genetics specialists. Inability to match the dysmorphology pattern to a known syndrome can pose a major diagnostic challenge. With an aim to accelerate the establishment of new syndromes and their genetic etiology, we describe our experience with multiplex consanguineous families that appeared to represent novel autosomal recessive dysmorphology syndromes at the time of evaluation. METHODS Combined autozygome/exome analysis of multiplex consanguineous families with apparently novel dysmorphology syndromes. RESULTS Consistent with the apparent novelty of the phenotypes, our analysis revealed a strong candidate variant in genes that were novel at the time of the analysis in the majority of cases, and 10 of these genes are published here for the first time as novel candidates (CDK9, NEK9, ZNF668, TTC28, MBL2, CADPS, CACNA1H, HYAL2, CTU2, and C3ORF17). A significant minority of the phenotypes (6/31, 19%), however, were caused by genes known to cause Mendelian phenotypes, thus expanding the phenotypic spectrum of the diseases linked to these genes. The conspicuous inheritance pattern and the highly specific phenotypes appear to have contributed to the high yield (90%) of plausible molecular diagnoses in our study cohort. CONCLUSION Reporting detailed clinical and genomic analysis of a large series of apparently novel dysmorphology syndromes will likely lead to a trend to accelerate the establishment of novel syndromes and their underlying genes through open exchange of data for the benefit of patients, their families, health-care providers, and the research community.Genet Med 18 7, 686-695.
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Affiliation(s)
- Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ruah Al-Yamany
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Agaadir ALMoisheer
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shamsa Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maha Alnemer
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohamed Elsheikh
- Department of Obstetrics and Gynecology, Suliman AlHabib Hospital, Riyadh, Saudi Arabia
| | - Khaled Alfaleh
- Department of Obstetrics and Gynecology, Suliman AlHabib Hospital, Riyadh, Saudi Arabia.,Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Muneera Alshammari
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Abdullah A Alangari
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Martin Kircher
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Riza M Daza
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Salma M Wakil
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ahmed Alaqeel
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ikhlas Altowaijri
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Amro Al-Habib
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Eissa Faqieh
- Department of Pediatrics, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Shamseldin H, Alazami A, Manning M, Hashem A, Caluseiu O, Tabarki B, Esplin E, Schelley S, Innes A, Parboosingh J, Lamont R, Majewski J, Bernier F, Alkuraya F, Alkuraya FS. RTTN Mutations Cause Primary Microcephaly and Primordial Dwarfism in Humans. Am J Hum Genet 2015; 97:862-8. [PMID: 26608784 DOI: 10.1016/j.ajhg.2015.10.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 10/20/2015] [Indexed: 10/22/2022] Open
Abstract
Primary microcephaly is a developmental brain anomaly that results from defective proliferation of neuroprogenitors in the germinal periventricular zone. More than a dozen genes are known to be mutated in autosomal-recessive primary microcephaly in isolation or in association with a more generalized growth deficiency (microcephalic primordial dwarfism), but the genetic heterogeneity is probably more extensive. In a research protocol involving autozygome mapping and exome sequencing, we recruited a multiplex consanguineous family who is affected by severe microcephalic primordial dwarfism and tested negative on clinical exome sequencing. Two candidate autozygous intervals were identified, and the second round of exome sequencing revealed a single intronic variant therein (c.2885+8A>G [p.Ser963(∗)] in RTTN exon 23). RT-PCR confirmed that this change creates a cryptic splice donor and thus causes retention of the intervening 7 bp of the intron and leads to premature truncation. On the basis of this finding, we reanalyzed the exome file of a second consanguineous family affected by a similar phenotype and identified another homozygous change in RTTN as the likely causal mutation. Combined linkage analysis of the two families confirmed that RTTN maps to the only significant linkage peak. Finally, through international collaboration, a Canadian multiplex family affected by microcephalic primordial dwarfism and biallelic mutation of RTTN was identified. Our results expand the phenotype of RTTN-related disorders, hitherto limited to polymicrogyria, to include microcephalic primordial dwarfism with a complex brain phenotype involving simplified gyration.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
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Alazami AM, Awad SM, Coskun S, Al-Hassan S, Hijazi H, Abdulwahab FM, Poizat C, Alkuraya FS. TLE6 mutation causes the earliest known human embryonic lethality. Genome Biol 2015; 16:240. [PMID: 26537248 PMCID: PMC4634911 DOI: 10.1186/s13059-015-0792-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 09/28/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Embryonic lethality is a recognized phenotypic expression of individual gene mutations in model organisms. However, identifying embryonic lethal genes in humans is challenging, especially when the phenotype is manifested at the preimplantation stage. RESULTS In an ongoing effort to exploit the highly consanguineous nature of the Saudi population to catalog recessively acting embryonic lethal genes in humans, we have identified two families with a female-limited infertility phenotype. Using autozygosity mapping and whole exome sequencing, we map this phenotype to a single mutation in TLE6, a maternal effect gene that encodes a member of the subcortical maternal complex in mammalian oocytes. Consistent with the published phenotype of mouse Tle6 mutants, embryos from female patients who are homozygous for the TLE6 mutation fail to undergo early cleavage, with resulting sterility. The human mutation abrogates TLE6 phosphorylation, a step that is reported to be critical for the PKA-mediated progression of oocyte meiosis II. Furthermore, the TLE6 mutation impairs its binding to components of the subcortical maternal complex. CONCLUSION In this first report of a human defect in a member of the subcortical maternal subcritical maternal complex, we show that the TLE6 mutation is gender-specific and leads to the earliest known human embryonic lethality phenotype.
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Affiliation(s)
- Anas M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Salma M Awad
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Serdar Coskun
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Center, Alfaisal University, Riyadh, Saudi Arabia
| | - Saad Al-Hassan
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hadia Hijazi
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous M Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Coralie Poizat
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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Faden M, AlZahrani F, Mendoza-Londono R, Dupuis L, Hartley T, Kannu P, Raiman J, Howard A, Qin W, Tetreault M, Xi J, Al-Thamer I, Maas R, Boycott K, Alkuraya F, Alkuraya FS. Identification of a Recognizable Progressive Skeletal Dysplasia Caused by RSPRY1 Mutations. Am J Hum Genet 2015; 97:608-15. [PMID: 26365341 DOI: 10.1016/j.ajhg.2015.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/10/2015] [Indexed: 02/02/2023] Open
Abstract
Skeletal dysplasias are highly variable Mendelian phenotypes. Molecular diagnosis of skeletal dysplasias is complicated by their extreme clinical and genetic heterogeneity. We describe a clinically recognizable autosomal-recessive disorder in four affected siblings from a consanguineous Saudi family, comprising progressive spondyloepimetaphyseal dysplasia, short stature, facial dysmorphism, short fourth metatarsals, and intellectual disability. Combined autozygome/exome analysis identified a homozygous frameshift mutation in RSPRY1 with resulting nonsense-mediated decay. Using a gene-centric "matchmaking" system, we were able to identify a Peruvian simplex case subject whose phenotype is strikingly similar to the original Saudi family and whose exome sequencing had revealed a likely pathogenic homozygous missense variant in the same gene. RSPRY1 encodes a hypothetical RING and SPRY domain-containing protein of unknown physiological function. However, we detect strong RSPRY1 protein localization in murine embryonic osteoblasts and periosteal cells during primary endochondral ossification, consistent with a role in bone development. This study highlights the role of gene-centric matchmaking tools to establish causal links to genes, especially for rare or previously undescribed clinical entities.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Fowzan S Alkuraya
- Department of Genetics, King Faisal and Research Center, Riyadh 11211, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
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ARL6IP6, a susceptibility locus for ischemic stroke, is mutated in a patient with syndromic Cutis Marmorata Telangiectatica Congenita. Hum Genet 2015; 134:815-22. [DOI: 10.1007/s00439-015-1561-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/27/2015] [Indexed: 10/23/2022]
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