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Zhang J, Hu G, Lu Y, Ren H, Huang Y, Wen Y, Ji B, Wang D, Wang H, Liu H, Ma N, Zhang L, Pan G, Qu Y, Wang H, Zhang W, Miao Z, Yao H. CTCF mutation at R567 causes developmental disorders via 3D genome rearrangement and abnormal neurodevelopment. Nat Commun 2024; 15:5524. [PMID: 38951485 PMCID: PMC11217373 DOI: 10.1038/s41467-024-49684-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/14/2024] [Indexed: 07/03/2024] Open
Abstract
The three-dimensional genome structure organized by CTCF is required for development. Clinically identified mutations in CTCF have been linked to adverse developmental outcomes. Nevertheless, the underlying mechanism remains elusive. In this investigation, we explore the regulatory roles of a clinically relevant R567W point mutation, located within the 11th zinc finger of CTCF, by introducing this mutation into both murine models and human embryonic stem cell-derived cortical organoid models. Mice with homozygous CTCFR567W mutation exhibit growth impediments, resulting in postnatal mortality, and deviations in brain, heart, and lung development at the pathological and single-cell transcriptome levels. This mutation induces premature stem-like cell exhaustion, accelerates the maturation of GABAergic neurons, and disrupts neurodevelopmental and synaptic pathways. Additionally, it specifically hinders CTCF binding to peripheral motifs upstream to the core consensus site, causing alterations in local chromatin structure and gene expression, particularly at the clustered protocadherin locus. Comparative analysis using human cortical organoids mirrors the consequences induced by this mutation. In summary, this study elucidates the influence of the CTCFR567W mutation on human neurodevelopmental disorders, paving the way for potential therapeutic interventions.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Gongcheng Hu
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Yuli Lu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Huawei Ren
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, China
| | - Yin Huang
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Yulin Wen
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Binrui Ji
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Diyang Wang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Haidong Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, China
| | - Huisheng Liu
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Ning Ma
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Lingling Zhang
- Institute of Clinical Pharmacology, Key Laboratory of Anti-Inflammatory and Immune Medicine (Ministry of Education), Anhui Medical University, Hefei, China
| | - Guangjin Pan
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yibo Qu
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Hua Wang
- Institute of Clinical Pharmacology, Key Laboratory of Anti-Inflammatory and Immune Medicine (Ministry of Education), Anhui Medical University, Hefei, China
| | - Wei Zhang
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Zhichao Miao
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China
| | - Hongjie Yao
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
- Department of Basic Research, Guangzhou National Laboratory, Guangzhou, China.
- University of Chinese Academy of Sciences, Beijing, China.
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Luo S, Ren L, Wang R, Hu J, Wei W, Feng Y, Huang S. Functional analysis of a novel intronic variant of MCPH1 with autosomal recessive primary microcephaly. Heliyon 2024; 10:e30285. [PMID: 38818167 PMCID: PMC11137353 DOI: 10.1016/j.heliyon.2024.e30285] [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: 08/17/2023] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Autosomal Recurrent Primary Microscopic (MCPH, OMIM: 251200) is a neurodevelopmental disorder that is characterized by a noticeable decrease in brain size, particularly in the cerebral cortex, but with a normal brain structure and a non-progressive intellectual disability. MCPH1 has been identified as the gene that triggers primary microcephaly (MCPH1,OMIM: 607117). Here we report a case of autosomal recessive primary microcephaly as caused by a novel variant in the MCPH1 gene. Head circumference was measured by Magnetic Resonance Imaging (MRI), while the Wechsler Intelligence Scale was used to evaluate the intelligence of the individual being tested. B-ultrasound was used to assess gonadal development, and semen routine was used to assess sperm status. The whole-exome sequencing (WES) was performed on the proband. Sanger sequencing was conducted on the parents of the proband to determine if the novel variant in the MCPH1 gene was present. The effect of the mutation on the splicing of MCPH1 was verified by minigene approach. It was observed that the proband had autosomal recessive primary microcephaly and azoospermatism. A novel splice-site homozygous mutation (c.233+2T > G) of the MCPH1 gene was identified, which inherited from his parents. Minigene approach confirmed that c.233+2T > G could affect the splicing of MCPH1. Therefore, our findings contributed to the mutation spectrum of the MCPH1 gene and may be useful in the diagnosis and gene therapy of MCPH.
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Affiliation(s)
- Shulin Luo
- Department of Medical Genetics/Prenatal Diagnosis Center, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Lingyan Ren
- Department of Medical Genetics/Prenatal Diagnosis Center, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Rongping Wang
- Department of Medical Imaging, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Jianxin Hu
- Department of Urology, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Wei Wei
- Department of Ultrasonography, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Yurong Feng
- Center for Rehabilitative Auditory Research, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
| | - Shengwen Huang
- Department of Medical Genetics/Prenatal Diagnosis Center, Guizhou Provincial People's Hospital, Guiyang, Guizhou Province, 550003, China
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Aamer W, Al-Maraghi A, Syed N, Gandhi GD, Aliyev E, Al-Kurbi AA, Al-Saei O, Kohailan M, Krishnamoorthy N, Palaniswamy S, Al-Malki K, Abbasi S, Agrebi N, Abbaszadeh F, Akil ASAS, Badii R, Ben-Omran T, Lo B, Mokrab Y, Fakhro KA. Burden of Mendelian disorders in a large Middle Eastern biobank. Genome Med 2024; 16:46. [PMID: 38584274 PMCID: PMC11000384 DOI: 10.1186/s13073-024-01307-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 02/19/2024] [Indexed: 04/09/2024] Open
Abstract
BACKGROUND Genome sequencing of large biobanks from under-represented ancestries provides a valuable resource for the interrogation of Mendelian disease burden at world population level, complementing small-scale familial studies. METHODS Here, we interrogate 6045 whole genomes from Qatar-a Middle Eastern population with high consanguinity and understudied mutational burden-enrolled at the national Biobank and phenotyped for 58 clinically-relevant quantitative traits. We examine a curated set of 2648 Mendelian genes from 20 panels, annotating known and novel pathogenic variants and assessing their penetrance and impact on the measured traits. RESULTS We find that 62.5% of participants are carriers of at least 1 known pathogenic variant relating to recessive conditions, with homozygosity observed in 1 in 150 subjects (0.6%) for which Peninsular Arabs are particularly enriched versus other ancestries (5.8-fold). On average, 52.3 loss-of-function variants were found per genome, 6.5 of which affect a known Mendelian gene. Several variants annotated in ClinVar/HGMD as pathogenic appeared at intermediate frequencies in this cohort (1-3%), highlighting Arab founder effect, while others have exceedingly high frequencies (> 5%) prompting reconsideration as benign. Furthermore, cumulative gene burden analysis revealed 56 genes having gene carrier frequency > 1/50, including 5 ACMG Tier 3 panel genes which would be candidates for adding to newborn screening in the country. Additionally, leveraging 58 biobank traits, we systematically assess the impact of novel/rare variants on phenotypes and discover 39 candidate large-effect variants associating with extreme quantitative traits. Furthermore, through rare variant burden testing, we discover 13 genes with high mutational load, including 5 with impact on traits relevant to disease conditions, including metabolic disorder and type 2 diabetes, consistent with the high prevalence of these conditions in the region. CONCLUSIONS This study on the first phase of the growing Qatar Genome Program cohort provides a comprehensive resource from a Middle Eastern population to understand the global mutational burden in Mendelian genes and their impact on traits in seemingly healthy individuals in high consanguinity settings.
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Affiliation(s)
- Waleed Aamer
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | | | - Najeeb Syed
- Applied Bioinformatics Core, Sidra Medicine, Doha, Qatar
| | | | - Elbay Aliyev
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | | | - Omayma Al-Saei
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | | | | | | | | | - Saleha Abbasi
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | - Nourhen Agrebi
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | | | | | - Ramin Badii
- Diagnostic Genomic Division, Hamad Medical Corporation, Doha, Qatar
| | - Tawfeg Ben-Omran
- Section of Clinical and Metabolic Genetics, Department of pediatrics, Hamad Medical Corporation, Doha, Qatar
- Department of Pediatric, Weill Cornell Medical College, Doha, Qatar
- Division of Genetic & Genomics Medicine, Sidra Medicine, Doha, Qatar
| | - Bernice Lo
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Younes Mokrab
- Department of Human Genetics, Sidra Medicine, Doha, Qatar.
- Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.
- College of Health Sciences, Qatar University, Doha, Qatar.
| | - Khalid A Fakhro
- Department of Human Genetics, Sidra Medicine, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
- Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.
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Campbell L, Fredericks J, Mathivha K, Moshesh P, Coovadia A, Chirwa P, Dillon B, Ghoor A, Lawrence D, Nair L, Mabaso N, Mokwele D, Novellie M, Krause A, Carstens N. The implementation and utility of clinical exome sequencing in a South African infant cohort. Front Genet 2023; 14:1277948. [PMID: 38028619 PMCID: PMC10665497 DOI: 10.3389/fgene.2023.1277948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Genetic disorders are significant contributors to infant hospitalization and mortality globally. The early diagnosis of these conditions in infants remains a considerable challenge. Clinical exome sequencing (CES) has shown to be a successful tool for the early diagnosis of genetic conditions, however, its utility in African infant populations has not been investigated. The impact of the under-representation of African genomic data, the cost of testing, and genomic workforce shortages, need to be investigated and evidence-based implementation strategies accounting for locally available genetics expertise and diagnostic infrastructure need to be developed. We evaluated the diagnostic utility of singleton CES in a cohort of 32 ill, South African infants from two State hospitals in Johannesburg, South Africa. We analysed the data using a series of filtering approaches, including a curated virtual gene panel consisting of genes implicated in neonatal-and early childhood-onset conditions and genes with known founder and common variants in African populations. We reported a diagnostic yield of 22% and identified seven pathogenic variants in the NPHS1, COL2A1, OCRL, SHOC2, TPRV4, MTM1 and STAC3 genes. This study demonstrates the utility value of CES in the South African State healthcare setting, providing a diagnosis to patients who would otherwise not receive one and allowing for directed management. We anticipate an increase in the diagnostic yield of our workflow with further refinement of the study inclusion criteria. This study highlights important considerations for the implementation of genomic medicine in under-resourced settings and in under-represented African populations where variant interpretation remains a challenge.
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Affiliation(s)
- L. Campbell
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - J. Fredericks
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - K. Mathivha
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Moshesh
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Coovadia
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Chirwa
- Nelson Mandela Children’s Hospital, Johannesburg, South Africa
| | - B. Dillon
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Ghoor
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Lawrence
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - L. Nair
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Mabaso
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Mokwele
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - M. Novellie
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Krause
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Carstens
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
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Fida M, Sinan I, Finan A. Whole Exome Sequencing Achieved a Definite Diagnosis of Kaufman Oculocerebrofacial Syndrome in a Bahraini Family: A Case Report. Clin Med Insights Pediatr 2023; 17:11795565231200130. [PMID: 37745637 PMCID: PMC10515509 DOI: 10.1177/11795565231200130] [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: 04/11/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
A 1 year and 7 months old girl presented to the medical genetic clinic as a referral from the pediatrics clinic. Upon examining the patient and assessing past medical history, an autosomal recessive disorder was suspected. The family underwent whole exome sequencing, which resulted in the diagnosis of Kaufman oculocerebrofacial syndrome (OMIM #244450) in the patient due to the fact that both parents were heterozygous carriers of a novel pathogenic variant in the gene UBE3B that lies on 12q24. It has been recommended for the family that preimplantation genetic testing should be considered for future pregnancies. In this case report, we present a novel variant of the gene and highlight the support of whole exome sequencing in the unveiling of genetic disorders.
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Affiliation(s)
- Mariam Fida
- Consultant, Medical Genetics, Bahrain Oncology Centre, Muharraq, Kingdom of Bahrain
| | - Israa Sinan
- Education and Proficiency Centre, King Hamad University Hospital, Muharraq, Kingdom of Bahrain
| | - Alan Finan
- Consultant, Department of Pediatrics, King Hamad University Hospital, Muharraq, Kingdom of Bahrain
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Masri AT, Oweis L, Ali M, Hamamy H. Global developmental delay and intellectual disability in the era of genomics: Diagnosis and challenges in resource limited areas. Clin Neurol Neurosurg 2023; 230:107799. [PMID: 37236004 DOI: 10.1016/j.clineuro.2023.107799] [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: 01/13/2023] [Revised: 05/12/2023] [Accepted: 05/22/2023] [Indexed: 05/28/2023]
Abstract
AIMS To report the diagnostic yield of clinical singleton whole exome sequencing (WES) performed among a group of Jordanian children presenting with global developmental delay /intellectual disability (GDD/ID), discuss the underlying identified genetic disorders and the challenges encountered. PATIENTS AND METHODS This retrospective medical record review study included 154 children who were diagnosed with GDD/ID at our clinic at Jordan University Hospital between 2016 and 2021, and whose diagnostic work up included WES. RESULTS Consanguinity among parents was reported in 94/154 (61.0%) patients and history of other affected siblings in 35/154 (22.7%) patients. Pathogenic and likely pathogenic variants (solved cases) were reported in 69/154 (44.8%) patients, a variant of uncertain significance was reported in 54/154 (35.0%) and a negative result was reported in 31/154 (20.1%) cases. In the solved cases, autosomal recessive diseases were the most common (33/69; 47.8%). Metabolic disorders were identified in 20/69 (28.9%) patients, followed by developmental and epileptic encephalopathies (9/69; 13.0%) and MECP2 related disorders (7/69; 10.1%). Other single gene disorders were identified in 33/69; 47.8%) patients. CONCLUSION This study had several limitations, as it was hospital-based and only including patients who were able to afford the test. Nevertheless, it yielded several important findings. In resource-limited countries, WES may be a reasonable approach. We discussed the challenges that clinicians meet in the context of shortage of resources.
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Affiliation(s)
- Amira T Masri
- Faculty of Medicine, Paediatric Department, Division of Child Neurology, The University of Jordan, Jordan.
| | - Liyana Oweis
- Faculty of Medicine, The University of Jordan, Jordan
| | - Majd Ali
- Faculty of Medicine, The University of Jordan, Jordan
| | - Hanan Hamamy
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
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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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Elsayed O, Al‐Shamsi A. Mutation spectrum of non-syndromic hearing loss in the UAE, a retrospective cohort study and literature review. Mol Genet Genomic Med 2022; 10:e2052. [PMID: 36056583 PMCID: PMC9651598 DOI: 10.1002/mgg3.2052] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/23/2022] [Accepted: 08/15/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Hearing loss (HL) is a heterogeneous condition that causes partial or complete hearing impairment. Hundreds of variants in >60 genes have been reported to be associated with Hereditary HL (HHL), variants of the GJB2 gene are the most common cause of congenital SNHL, with >100 variants reported. The HHL prevalence is thought to be high in the Arab population; however, the genetic epidemiology of HHL among Emirati populations is understudied. AIMS To shed light on the mutational spectrum of NSHL in Emirati patients seen in the genetic clinic over 10 years and to capture founder mutation(s) if any were identified. METHODS Retrospective chart review of all Emirati patients assessed by clinical geneticists due to NSHL during the period between January 2010 to December 2020. Genetic tests were done based on clinical phenotypes of the patient and family history including targeted mutation testing, next-generation sequencing, or whole-exome sequencing (solo or trio). The authors did literature reviews using PubMed for all previously reported articles related to NSHL genes from UAE. RESULTS A total of 162 patients with HL, were evaluated during the period between January 2010 to December 2020. There were 82 patients with NSHL, and only 72 patients who completed the genetic evaluations were included in this retrospective study. Among the studied group, 42 (51.2%) were males and 40 (48.78%) were females. The youngest patient was 2 years old and the oldest patient was 50 years old. Consanguinity was documented in 76 patients (92.68%). A total of 14 mutations reported here are novel (23/72 i.e., 31.9%). Twelve missense mutations, 6 nonsense mutations, 6 frameshift mutations, 2 in-frame deletion mutations, and 1 splice site mutation was found. Variants in the GJB2 gene are the most commonly identified cause of NSHL, with c.35delG being the most followed by c.506G > A. The second commonly found variant is c.934C > G (p.Arg312Gly) in the CDC14A gene, found in 9 patients. This was followed by variants in OTOF and SLC26A4 genes, found in 8 patients, respectively. Chromosomal microdeletions encompassing genes causing NSHL were found in 3 patients. No mitochondrial mutations were found in this study group. A total of 11 previous reports about Emirati patients with NSHL were reviewed, with a total of 35 patients. CONCLUSION Emirati patients with NSHL have several mutations, most notably missense mutations. Novel mutations are worth further testing and represent the area for future researches.
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Affiliation(s)
- Omnia Elsayed
- Pediatrics DepartmentTawam HospitalAl AinUnited Arab Emirates
| | - Aisha Al‐Shamsi
- Genetic Division, Pediatrics DepartmentTawam HospitalAl AinUnited Arab Emirates
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