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A CRISPR and high-content imaging assay compliant with ACMG/AMP guidelines for clinical variant interpretation in ciliopathies. Hum Genet 2020; 140:593-607. [PMID: 33095315 PMCID: PMC7981318 DOI: 10.1007/s00439-020-02228-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/14/2020] [Indexed: 11/04/2022]
Abstract
Ciliopathies are a broad range of inherited developmental and degenerative diseases associated with structural or functional defects in motile or primary non-motile cilia. There are around 200 known ciliopathy disease genes and whilst genetic testing can provide an accurate diagnosis, 24–60% of ciliopathy patients who undergo genetic testing do not receive a genetic diagnosis. This is partly because following current guidelines from the American College of Medical Genetics and the Association for Molecular Pathology, it is difficult to provide a confident clinical diagnosis of disease caused by missense or non-coding variants, which account for more than one-third of cases of disease. Mutations in PRPF31 are the second most common cause of the degenerative retinal ciliopathy autosomal dominant retinitis pigmentosa. Here, we present a high-throughput high-content imaging assay providing quantitative measure of effect of missense variants in PRPF31 which meets the recently published criteria for a baseline standard in vitro test for clinical variant interpretation. This assay utilizes a new PRPF31+/– human retinal cell line generated using CRISPR gene editing to provide a stable cell line with significantly fewer cilia in which novel missense variants are expressed and characterised. We show that high-content imaging of cells expressing missense variants in a ciliopathy gene on a null background can allow characterisation of variants according to the cilia phenotype. We hope that this will be a useful tool for clinical characterisation of PRPF31 variants of uncertain significance, and can be extended to variant classification in other ciliopathies.
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102
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McConnachie DJ, Stow JL, Mallett AJ. Ciliopathies and the Kidney: A Review. Am J Kidney Dis 2020; 77:410-419. [PMID: 33039432 DOI: 10.1053/j.ajkd.2020.08.012] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/11/2020] [Indexed: 12/19/2022]
Abstract
Primary cilia are specialized sensory organelles that protrude from the apical surface of most cell types. During the past 2 decades, they have been found to play important roles in tissue development and signal transduction, with mutations in ciliary-associated proteins resulting in a group of diseases collectively known as ciliopathies. Many of these mutations manifest as renal ciliopathies, characterized by kidney dysfunction resulting from aberrant cilia or ciliary functions. This group of overlapping and genetically heterogeneous diseases includes polycystic kidney disease, nephronophthisis, and Bardet-Biedl syndrome as the main focus of this review. Renal ciliopathies are characterized by the presence of kidney cysts that develop due to uncontrolled epithelial cell proliferation, growth, and polarity, downstream of dysregulated ciliary-dependent signaling. Due to cystic-associated kidney injury and systemic inflammation, cases result in kidney failure requiring dialysis and transplantation. Of the handful of pharmacologic treatments available, none are curative. It is important to determine the molecular mechanisms that underlie the involvement of the primary cilium in cyst initiation, expansion, and progression for the development of novel and efficacious treatments. This review updates research progress in defining key genes and molecules central to ciliogenesis and renal ciliopathies.
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Affiliation(s)
- Dominique J McConnachie
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation Disease and Research, The University of Queensland, Brisbane, QLD, Australia
| | - Jennifer L Stow
- Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Andrew J Mallett
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation Disease and Research, The University of Queensland, Brisbane, QLD, Australia; Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia; Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia; KidGen Collaborative, Australian Genomics Health Alliance, Melbourne, VIC, Australia.
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103
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Shen Y, Wang H, Liu Z, Luo M, Ma S, Lu C, Cao Z, Yu Y, Cai R, Chen C, Li Q, Gao H, Peng Y, Xu B, Ma X. Identification of two novel pathogenic variants of PIBF1 by whole exome sequencing in a 2-year-old boy with Joubert syndrome. BMC MEDICAL GENETICS 2020; 21:192. [PMID: 33004012 PMCID: PMC7531107 DOI: 10.1186/s12881-020-01130-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 09/22/2020] [Indexed: 01/20/2023]
Abstract
Background Joubert syndrome (OMIM 213300) is an autosomal recessive disorder with gene heterogeneity. Causal genes and their variants have been identified by sequencing or other technologies for Joubert syndrome subtypes. Case presentation A two-year-old boy was diagnosed with Joubert syndrome by global development delay and molar tooth sign of mid-brain. Whole exome sequencing was performed to detect the causative gene variants in this individual, and the candidate pathogenic variants were verified by Sanger sequencing. We identified two pathogenic variants (NM_006346.2: c.1147delC and c.1054A > G) of PIBF1 in this Joubert syndrome individual, which is consistent with the mode of autosomal recessive inheritance. Conclusion In this study, we identified two novel pathogenic variants in PIBF1 in a Joubert syndrome individual using whole exome sequencing, thereby expanding the PIBF1 pathogenic variant spectrum of Joubert syndrome.
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Affiliation(s)
- Yue Shen
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Hao Wang
- China National Clinical Research Center of Respiratory Diseases, Respiratory Department of Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Zhimin Liu
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Minna Luo
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Siyu Ma
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Chao Lu
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Zongfu Cao
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Yufei Yu
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Ruikun Cai
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Cuixia Chen
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Qian Li
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Huafang Gao
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Yun Peng
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Baoping Xu
- China National Clinical Research Center of Respiratory Diseases, Respiratory Department of Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
| | - Xu Ma
- National Research Institute for Family Planning, Beijing, China. .,National Human Genetic Resources Center, Beijing, China.
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104
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Khan MI, Latif M, Saif M, Ahmad H, Khan AU, Naseer MI, Hussain HMJ, Jelani M. Whole exome sequencing identified a novel missense alteration in CC2D2A causing Joubert syndrome 9 in a Pakhtun family. J Gene Med 2020; 23:e3279. [PMID: 32989887 DOI: 10.1002/jgm.3279] [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: 04/15/2020] [Revised: 09/21/2020] [Accepted: 09/21/2020] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Joubert syndrome (JBTS) is a heterogenous disorder characterized by intellectual disability, developmental delays, molar tooth sign in brain imaging, hypotonia, ocular motor apraxia and overlapping features of ciliopathies. There are 36 clinical subtypes of JBTS, with an equal number of genes known so far for this phenotype. METHODS Whole exome sequencing (WES) and Sanger sequencing were performed for the molecular diagnosis of a Pakhtun family affected with Joubert syndrome type 9 (JBTS9). RESULTS A novel homozygous missense variant (c.4417C>G; Pro1473Ala) in exon 34 was identified in coiled-coil and C2 domains-containing the protein 2A (CC2D2A; NM_001080522) gene. The variant co-segregated in autosomal recessive fashion within the family and was not found in 200 ethnically matched unaffected individuals. In silico analyses supported the pathogenic effect of the altered CC2D2A protein. CONCLUSIONS To the best of our knowledge, this is the first report of CC2D2A alteration co-segragating with a JBTS9 phenotype in a Pakhtun family from Pakistan. Our findings broaden the pathogenic spectrum of JBTS9, adding a novel variant to CC2D2A variation pool. WES analysis is a successful molecular diagnostic tool for rare genetic disorders, especially in those populations where the marriage of cousins is more frequent. Efficient and accurate genetic testing and counselling of the affected families are helpful for patient management and for reducing the disease burden in future generations.
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Affiliation(s)
- Muhammad Ismail Khan
- Department of Zoology, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Latif
- Centre for Genetics and Inherited Diseases (CGID), Taibah University, Al-Madinah, Al-Munawwarah, Saudi Arabia
| | - Maria Saif
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Hilal Ahmad
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Atta Ullah Khan
- Department of Medicine, Pak International Medical College Phase 5, Hayatabad Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Musharraf Jelani
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
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105
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Zhang YW, Qu HB, Long N, Leng XY, Liu YQ, Yang Y. A rare mutant of OFD1 gene responsible for Joubert syndrome with significant phenotype variation. Mol Genet Genomics 2020; 296:33-40. [PMID: 32944789 DOI: 10.1007/s00438-020-01726-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/09/2020] [Indexed: 02/05/2023]
Abstract
Joubert syndrome (JBTS), a rare genetic disorder resulted from primary cilium defects or basal-body dysfunction, is characterized by agenesis of cerebellar vermis and abnormal brain stem. Both genotypes and phenotypes of JBTS are highly heterogeneous. The identification of pathogenic gene variation is essential for making a definite diagnosis on JBTS. Here, we found that hypoplasia of cerebellar vermis occurred in three male members in a Chinese family. Then, we performed whole exome sequencing to identify a novel missense mutation c.599T > C (p. L200P) in the OFD1 gene which is the candidate gene of X-linked JBTS (JBST10). The following analysis showed that the variant was absent in the 1000 Genomes, ExAC and the 200 female controls; the position 200 Leucine residue was highly conserved across species; the missense variant was predicted to be deleterious using PolyPhen-2, PROVEAN, SIFT and Mutation Taster. The OFD1 expression was heavily lower in the proband and an induced male fetus compared with a healthy male with a wild-type OFD1 gene. The in vitro expression analysis of transiently transfecting c.599T or c.599C plasmids into HEK-293T cells confirmed that the missense mutation caused OFD1 reduction at the protein level. And further the mutated OFD1 decreased the level of Gli1 protein, a read-out of Sonic hedgehog (SHH) signaling essential for development of central neural system. A known pathogenic variant c.515T > C (p. L172P) showed the similar results. All of these observations suggested that the missense mutation causes the loss function of OFD1, resulting in SHH signaling impairs and brain development abnormality. In addition, the three patients have Dandy-Walker malformation, macrogyria and tetralogy of Fallot, respectively, the latter two of which are firstly found in JBTS10 patients. In conclusion, our findings expand the context of genotype and phenotype in the JBTS10 patients.
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Affiliation(s)
- Yang-Wei Zhang
- State Key Laboratory of Biotherapy, Department of Medical Genetics, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China.,Department of Neurology, The Second Clinical Institute of North Sichuan Medical College, Nanchong Central Hospital, Nanchong, China
| | - Hai-Bo Qu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Department of Radiology, Ministry of Education, West China Second University Hospital, Chengdu, 610041, China
| | - Ning Long
- Department of Obstetrics and Gynecology, The Second Clinical Institute of North Sichuan Medical College, Nanchong Central Hospital, Nanchong, China
| | - Xiang-You Leng
- State Key Laboratory of Biotherapy, Department of Medical Genetics, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Yun-Qiang Liu
- State Key Laboratory of Biotherapy, Department of Medical Genetics, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Yuan Yang
- State Key Laboratory of Biotherapy, Department of Medical Genetics, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China.
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106
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Ruberto G, Parisi V, Bertone C, Signorini S, Antonini M, Valente EM, Manzoni F, Serpieri V, Fausto R, Quaranta L. Electroretinographic Assessment in Joubert Syndrome: A Suggested Objective Method to Evaluate the Effectiveness of Future Targeted Treatment. Adv Ther 2020; 37:3827-3838. [PMID: 32671685 PMCID: PMC7444391 DOI: 10.1007/s12325-020-01432-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Joubert syndrome (JS) is an autosomal recessive disorder characterized by a congenital malformation of the mid-hindbrain and a large spectrum of clinical features including congenital retinal dystrophy. The function of different retinal elements (rod, cone, bipolar cells) can be objectively evaluated by electroretinogram (ERG) recordings. Our work aims to evaluate the retinal function (by ERG recordings) in patients with JS with or without congenital retinal dystrophy. In addition, since clinical trials should be performed in the near future in JS, our results could provide information about the possible usefulness of ERG recordings in the assessment of the efficacy of treatments targeted to improve the retinal involvement. METHODS In this observational and prospective study, 24 children with genetic identification for JS (mean age 10.75 ± 6.59 years) and 25 healthy age-similar normal control subjects (control group, mean age 10.55 ± 3.76 years) were enrolled. On the basis of the presence/absence of retinal dystrophy at fundus examination, patients with JS were divided into two groups: patients with JS with retinal dystrophy (16 children, mean age 11.00 ± 6.74 years, providing 16 eyes; JS-RD group) and patients with JS without retinal dystrophy (8 children, mean age 10.50 ± 6.45 years, providing 8 eyes; JS-NRD group). In patients with JS and controls, visual acuity (VA), dark-adapted, light-adapted, and 30-Hz flicker ERGs were performed according to International Society for Clinical Electrophysiology of Vision (ISCEV) standard protocols. RESULTS When compared to controls, patients in the JS-RD and JS-NRD groups showed significant abnormalities of the values of dark-adapted, light-adapted, and 30-Hz flicker ERG parameters. The ERG and VA changes were not significantly correlated. CONCLUSIONS Our results suggest that a dysfunction of photoreceptors and bipolar cells occurs in patients with JS with or without retinal dystrophy. The retinal impairment can be detected by ERG recordings and this method should be proposed to evaluate the effectiveness of adequate treatment targeted to improve the retinal impairment in patients with JS.
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107
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Sallum JMF, Motta FL, Arno G, Porto FBO, Resende RG, Belfort R. Clinical and molecular findings in a cohort of 152 Brazilian severe early onset inherited retinal dystrophy patients. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:728-752. [PMID: 32865313 DOI: 10.1002/ajmg.c.31828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022]
Abstract
Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD) are severe inherited retinal dystrophy that can cause deep blindness childhood. They represent 5% of all retinal dystrophies in the world population and about 10% in Brazil. Clinical findings and molecular basis of syndromic and nonsyndromic LCA/EORD in a Brazilian sample (152 patients/137 families) were studied. In this population, 15 genes were found to be related to the phenotype, 38 new variants were detected and four new complex alleles were discovered. Among 123 variants found, the most common were CEP290: c.2991+1655A>G, CRB1: p.Cys948Tyr, and RPGRIP1: exon10-18 deletion.
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Affiliation(s)
- Juliana Maria Ferraz Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Fabiana Louise Motta
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Gavin Arno
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | - Fernanda Belga Ottoni Porto
- INRET Clínica e Centro de Pesquisa, Belo Horizonte, Minas Gerais, Brazil.,Centro Oftalmológico de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Rubens Belfort
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil
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108
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Bhowmick SS, Lang AE. Movement Disorders and Renal Diseases. Mov Disord Clin Pract 2020; 7:763-779. [PMID: 33043074 DOI: 10.1002/mdc3.13005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023] Open
Abstract
Movement disorders often emerge from the interplay of complex pathophysiological processes involving the kidneys and the nervous system. Tremor, myoclonus, ataxia, chorea, and parkinsonism can occur in the context of renal dysfunction (azotemia and electrolyte abnormalities) or they can be part of complications of its management (dialysis and renal transplantation). On the other hand, myoglobinuria from rhabdomyolysis in status dystonicus and certain drugs used in the management of movement disorders can cause nephrotoxicity. Distinct from these well-recognized associations, it is important to appreciate that there are several inherited and acquired disorders in which movement abnormalities do not occur as a consequence of renal dysfunction or vice versa but are manifestations of common pathophysiological processes affecting the nervous system and the kidneys. These disorders are the emphasis of this review. Increasing awareness of these conditions among neurologists may help them to identify renal involvement earlier, take timely intervention by anticipating complications and focus on therapies targeting common mechanisms in addition to symptomatic management of movement disorders. Recognition of renal impairment in a patient with complex neurological presentation may narrow down the differentials and aid in reaching a definite diagnosis.
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Affiliation(s)
- Suvorit S Bhowmick
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
| | - Anthony E Lang
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
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109
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Etchegaray A, Juarez-Peñalva S, Petracchi F, Igarzabal L. Prenatal genetic considerations in congenital ventriculomegaly and hydrocephalus. Childs Nerv Syst 2020; 36:1645-1660. [PMID: 32006096 DOI: 10.1007/s00381-020-04526-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 01/25/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Fetal ventriculomegaly (VM) is a frequent finding in prenatal ultrasound. Rather than a proper diagnosis, VM is a sonographic sign, making prenatal counseling a complex and challenging undertaking. VM can range from severe pathologic processes leading to severe neurodevelopmental delay to normal variants. DISCUSSION A growing number of genetic conditions with different pathophysiological mechanisms, inheritance patterns, and long-term prognosis have been associated both to isolated and complex fetal VM. These include chromosomal abnormalities, copy number variants, and several single gene diseases. In this review, we describe some of the most common genetic conditions associated with fetal VM and provide a simplified diagnostic workflow for the clinician.
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Affiliation(s)
- Adolfo Etchegaray
- Unidad de Medicina Fetal, Hospital Universitario Austral, Pilar, Buenos Aires, Argentina.
| | - Sofia Juarez-Peñalva
- Unidad de Medicina Fetal, Hospital Universitario Austral, Pilar, Buenos Aires, Argentina
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110
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Liu Q, Wang H, Zhao J, Liu Z, Sun D, Yuan A, Luo G, Wei W, Hou M. Four novel compound heterozygous mutations in C5orf42 gene in patients with pure and mild Joubert syndrome. Int J Dev Neurosci 2020; 80:455-463. [PMID: 32233090 DOI: 10.1002/jdn.10029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/09/2020] [Accepted: 03/17/2020] [Indexed: 01/03/2023] Open
Abstract
Joubert syndrome (JS) is a rare clinically and genetically heterogeneous disease. Using whole or targeted exome sequencing, we identified four novel compound heterozygous mutations in chromosome 5 open reading frame 42 gene (C5orf42), including c.2876C>T (missense mutation) and c.3921+1G>A (splicing mutation), c.2292 -2delA (splicing mutation) and c.4067C>T (missense mutation), c.6997_6998insT (frameshift mutation) and c.8710C>T (nonsense mutation), c.3981G>C (nonsense mutation) and c.230 _233del (frameshift mutation), in four Chinese JS families. They were all inherited from their heterozygosis parents in the autosomal recessive inheritance mode. Pure JS clinical manifestations and mild neuroimaging findings were found in these patients. These verified the previous findings that C5orf42 mutations generally resulted in a purely neurological Joubert phenotype, and neuroimaging findings were mild in JS with C5orf42 mutations. Our report analyzed these C5orf42 mutations-associated phenotypes and neuroimaging findings in JS and updated the genetic variation spectrum of JS caused by C5orf42.These will help clinicians and geneticists reach a more accurate diagnosis for JS.
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Affiliation(s)
- Qiuyan Liu
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Haiqiao Wang
- Department of Traditional Chinese Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiaotong University, Shanghai, P.R. China
| | - Jianhui Zhao
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Zhicui Liu
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Dianrong Sun
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Aiyun Yuan
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Guangjin Luo
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
| | - Wei Wei
- Kangso Medical Inspection Co., Ltd, Beijing, P.R. China
| | - Mei Hou
- Department of Neurology and Rehabilitation, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, P.R. China
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111
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Katiyar D, Anderson N, Bommireddipalli S, Bournazos A, Cooper S, Goel H. Two novel B9D1 variants causing Joubert syndrome: Utility of mRNA and splicing studies. Eur J Med Genet 2020; 63:104000. [PMID: 32622957 DOI: 10.1016/j.ejmg.2020.104000] [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: 04/08/2020] [Revised: 05/28/2020] [Accepted: 06/28/2020] [Indexed: 11/26/2022]
Abstract
The primary cilium is an organelle which plays an important role in the transduction of signals in the Wnt and Sonic hedgehog pathways. Abnormal or absent primary cilia result in various neurodevelopmental, retinal, renal, hepatic and musculoskeletal abnormalities. Joubert syndrome (JS) is a ciliopathy with a prevalence estimated to be between 1:80 000 and 1:100 000. JS occurs due to bi-allelic mutations in one of the 34 identified genes, all of which encode for protein components of the primary cilia. The presentation of JS is highly variable, however a clinical diagnosis can be established by the presence of the molar tooth sign on axial brain MRI, hypotonia in infancy, and developmental delay. JS is less severe than Meckel syndrome (MKS), which is another recessive, and often lethal, ciliopathy. This report outlines an interesting case of JS, in which two novel mutations in B9D1 were identified. This gene is not commonly associated with JS, and is often implicated in MKS. Functional mRNA study was helpful in delineating the pathogenic role of novel variants in this case.
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Affiliation(s)
- Disha Katiyar
- University of New England, Armidale, NSW, 2351, Australia; University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Neil Anderson
- John Hunter Children's Hospital, Hunter New England Local Health District (HNELHD), New Lambton Heights, NSW, Australia
| | | | - Adam Bournazos
- Kids Neuroscience Centre, The Children's Hospital at Westmead Sydney, Australia
| | - Sandra Cooper
- Kids Neuroscience Centre, The Children's Hospital at Westmead Sydney, Australia
| | - Himanshu Goel
- University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Genetics, Hunter New England Local Health District (HNELHD), Waratah, NSW, 2298, Australia.
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112
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Nuovo S, Fuiano L, Micalizzi A, Battini R, Bertini E, Borgatti R, Caridi G, D’Arrigo S, Fazzi E, Fischetto R, Ghiggeri GM, Giordano L, Leuzzi V, Romaniello R, Signorini S, Stringini G, Zanni G, Romani M, Valente EM, Emma F. Impaired urinary concentration ability is a sensitive predictor of renal disease progression in Joubert syndrome. Nephrol Dial Transplant 2020; 35:1195-1202. [PMID: 30403813 PMCID: PMC7417010 DOI: 10.1093/ndt/gfy333] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/26/2018] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Joubert syndrome (JS) is an inherited ciliopathy characterized by a complex midbrain-hindbrain malformation and multiorgan involvement. Renal disease, mainly juvenile nephronophthisis (NPH), was reported in 25-30% patients although only ∼18% had a confirmed diagnosis of chronic kidney disease (CKD). NPH often remains asymptomatic for many years, resulting in delayed diagnosis. The aim of the study was to identify a biomarker able to quantify the risk of progressive CKD in young children with JS. METHODS Renal features were investigated in 93 Italian patients, including biochemical tests, ultrasound and 1-deamino-8D-arginine vasopressin test in children with reduced basal urine osmolality. A subset of patients was followed-up over time. RESULTS At last examination, 27 of 93 subjects (29%) presented with CKD, ranging from isolated urinary concentration defect (UCD) to end-stage renal disease. Both normal and pathological urine osmolality levels remained stable over time, even when obtained at very early ages. Follow-up data showed that the probability of developing CKD can be modelled as a function of the urine osmolality value, exceeding 75% for levels <600 mOsm/kg H2O, and significantly increased in patients with an early diagnosis of isolated UCD. CONCLUSIONS We conclude that the frequency of CKD in JS increases with age and is higher than previously reported. Urine osmolality represents an early sensitive quantitative biomarker of the risk of CKD progression.
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Affiliation(s)
- Sara Nuovo
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Laura Fuiano
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
| | | | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Enrico Bertini
- Laboratory of Molecular Medicine, Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
| | - Renato Borgatti
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Gianluca Caridi
- Laboratory of Molecular Nephrology, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - Stefano D’Arrigo
- Developmental Neurology Division, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Elisa Fazzi
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Rita Fischetto
- Clinical Genetics Unit, Department of Paediatric Medicine, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Gian Marco Ghiggeri
- Laboratory of Molecular Nephrology, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - Lucio Giordano
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Sabrina Signorini
- Unit of Child Neurology and Psychiatry, IRCCS C. Mondino Foundation, Pavia, Italy
| | - Gilda Stringini
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
| | - Ginevra Zanni
- Laboratory of Molecular Medicine, Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
| | - Marta Romani
- Molecular Genetics Laboratory, Eurofins GENOMA Group, Rome, Italy
| | - Enza Maria Valente
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
- Deparment of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Francesco Emma
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
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Wang X, Zhang Z, Zhang X, Shen Y, Liu H. Novel biallelic loss-of-function variants in CEP290 cause Joubert syndrome in two siblings. Hum Genomics 2020; 14:26. [PMID: 32600475 PMCID: PMC7325267 DOI: 10.1186/s40246-020-00274-4] [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: 01/09/2020] [Accepted: 06/11/2020] [Indexed: 12/03/2022] Open
Abstract
Background Joubert syndrome (JS) is a rare genetic disorder, which can be defined by brain stem malformation, cerebellar vermis hypoplasia, and consequent “molar tooth sign” (MTS). JS always shares variety of phenotypes in development defects. With the development of next-generation sequencing, dozens of causative genes have been identified to JS so far. Here, we investigated two male siblings with JS and uncovered a novel pathogenesis through combined methods. Results The siblings shared similar features of nystagmus, disorders of intellectual development, typical MTS, and abnormal morphology in fourth ventricle. Whole-exome sequencing (WES) and chromosome comparative genomic hybridization (CGH) were then performed on the proband. Strikingly, a maternal inherited nonsense variant (NM_025114.3: c.5953G>T [p.E1985*]) in CEP290 gene and a paternal inherited deletion in 12q21.32 including exons 1 to 10 of CEP290 gene were identified in the two affected siblings. We further confirmed the two variants by in vitro experiments: quantitative PCR and PCR sequencing. Conclusions In this study, we first reported a novel causative mechanism of Joubert syndrome: a copy number variation (CNV) combined with a single-nucleotide variant in CEP290 gene, which can be helpful in the genetic diagnosis of this disease.
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Affiliation(s)
- Xiang Wang
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Zhu Zhang
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China
| | - Xueguang Zhang
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Ying Shen
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| | - Hongqian Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China.
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114
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Clinical and Molecular Diagnosis of Joubert Syndrome and Related Disorders. Pediatr Neurol 2020; 106:43-49. [PMID: 32139166 DOI: 10.1016/j.pediatrneurol.2020.01.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/16/2020] [Accepted: 01/26/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Joubert syndrome and related disorders are a group of ciliopathies characterized by mid-hindbrain malformation, developmental delay, hypotonia, oculomotor apraxia, and breathing abnormalities. Molar tooth sign in brain imaging is the hallmark for diagnosis. Joubert syndrome is a clinically and genetically heterogeneous disorder involving mutations in 35 ciliopathy-related genes. We present a large cohort of 59 patients with Joubert syndrome from 55 families. Molecular analysis was performed in 35 families (trio). METHODS Clinical exome analysis was performed to identify causal mutations, and genotype-phenotype correlations were evaluated. RESULTS All of the cases were stratified into pure Joubert syndrome (62.7%), Joubert syndrome with retinal disease (22.0%), polydactyly (8.5%), and liver (1.7%) and kidney (1.7%) involvement. Joubert syndrome-related disorders include Meckel-Gruber syndrome in 5.1% cases and Leber congenital amaurosis (1.7%). Of the 35 Joubert syndrome-related genes, 11 were identified in these patients, i.e., CEP290, C5ORF, TCTN1, CC2D2A, RPGRP1L, TCTN3, AHI1, INPP5E, TCTN2, NPHP1, and TMEM237. For the first time, we identified a ciliopathy gene, CCDC28B, as a causal gene in Joubert syndrome in one family. CEP290 accounted for 37.8% cases of pure Joubert syndrome, Joubert syndrome with retinal and renal disease, and Meckel-Gruber syndrome. The p.G1890∗ allele in CEP290 is highly recurrent. Of the six families with Joubert syndrome who had a prenatal diagnosis, one fetus was normal, two were carriers, and three were affected. CONCLUSIONS This is the largest study of Joubert syndrome from India. Although a high degree of locus and allelic heterogeneity was observed, CEP290 variants were the most common among these patients.
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van Wijngaarden AL, Hiemstra YL, Koopmann TT, Ruivenkamp CAL, Aten E, Schalij MJ, Bax JJ, Delgado V, Barge-Schaapveld DQCM, Ajmone Marsan N. Identification of known and unknown genes associated with mitral valve prolapse using an exome slice methodology. J Med Genet 2020; 57:843-850. [PMID: 32277046 DOI: 10.1136/jmedgenet-2019-106715] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/18/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
Abstract
PURPOSE Although a familial distribution has been documented, the genetic aetiology of mitral valve prolapse (MVP) is largely unknown, with only four genes identified so far: FLNA, DCHS1, DZIP1 and PLD1. The aim of this study was to evaluate the genetic yield in known causative genes and to identify possible novel genes associated with MVP using a heart gene panel based on exome sequencing. METHODS Patients with MVP were referred for genetic counselling when a positive family history for MVP was reported and/or Barlow's disease was diagnosed. In total, 101 probands were included to identify potentially pathogenic variants in a set of 522 genes associated with cardiac development and/or diseases. RESULTS 97 (96%) probands were classified as Barlow's disease and 4 (4%) as fibroelastic deficiency. Only one patient (1%) had a likely pathogenic variant in the known causative genes (DCHS1). However, an interesting finding was that 10 probands (11%) had a variant that was classified as likely pathogenic in six different, mostly cardiomyopathy genes: DSP (1×), HCN4 (1×), MYH6 (1×), TMEM67 (1×), TRPS1 (1×) and TTN (5×). CONCLUSION Exome slice sequencing analysis performed in MVP probands reveals a low genetic yield in known causative genes but may expand the cardiac phenotype of other genes. This study suggests for the first time that also genes related to cardiomyopathy may be associated with MVP. This highlights the importance to screen these patients and their family for the presence of arrhythmias and of 'disproportionate' LV remodelling as compared with the severity of mitral regurgitation, unravelling a possible coexistent cardiomyopathy.
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Affiliation(s)
| | - Yasmine L Hiemstra
- Cardiology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Tamara T Koopmann
- Clinical Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Claudia A L Ruivenkamp
- Clinical Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Emmelien Aten
- Clinical Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Martin J Schalij
- Cardiology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Jeroen J Bax
- Cardiology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Victoria Delgado
- Cardiology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | | | - Nina Ajmone Marsan
- Cardiology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
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Niceta M, Dentici ML, Ciolfi A, Marini R, Barresi S, Lepri FR, Novelli A, Bertini E, Cappa M, Digilio MC, Dallapiccola B, Tartaglia M. Co-occurrence of mutations in KIF7 and KIAA0556 in Joubert syndrome with ocular coloboma, pituitary malformation and growth hormone deficiency: a case report and literature review. BMC Pediatr 2020; 20:120. [PMID: 32164589 PMCID: PMC7066839 DOI: 10.1186/s12887-020-2019-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/02/2020] [Indexed: 12/13/2022] Open
Abstract
Background Joubert syndrome is a recessive neurodevelopmental disorder characterized by clinical and genetic heterogeneity. Clinical hallmarks include hypotonia, ataxia, facial dysmorphism, abnormal eye movement, irregular breathing pattern cognitive impairment and, the molar tooth sign is the pathognomonic midbrain-hindbrain malformation on magnetic resonance imaging. The disorder is predominantly caused by biallelic mutations in more than 30 genes encoding proteins with a pivotal role in morphology and function of the primary cilium. Oligogenic inheritance or occurrence of genetic modifiers has been suggested to contribute to the variability of the clinical phenotype. We report on a family with peculiar clinical spectrum Joubert syndrome molecularly and clinically dissecting a complex phenotype, in which hypogonadism, pituitary malformation and growth hormone deficiency occur as major features. Case presentation A 7 year-old male was enrolled in a dedicated “Undiagnosed Patients Program” for a peculiar form of Joubert syndrome complicated by iris and retinochoroidal coloboma, hypogonadism pituitary malformation, and growth hormone deficiency. The molecular basis of the complex phenotype was investigated by whole exome sequencing. The concomitant occurrence of homozygosity for mutations in KIF7 and KIAA0556 was identified, and the assessment of major clinical features associated with mutations in these two genes provided evidence that these two independent events represent the cause underlying the complexity of the present clinical phenotype. Conclusion Beside the clinical variability of Joubert syndrome, co-occurrence of mutations in ciliopathy-associated genes may contribute to increase the clinical complexity of the trait.
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Affiliation(s)
- Marcello Niceta
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy.
| | - Maria Lisa Dentici
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Romana Marini
- Unit of Endocrinology, Academic Department of Pediatrics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Sabina Barresi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Francesca Romana Lepri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Antonio Novelli
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Enrico Bertini
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Marco Cappa
- Unit of Endocrinology, Academic Department of Pediatrics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Maria Cristina Digilio
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Bruno Dallapiccola
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
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Collard E, Byrne C, Georgiou M, Michaelides M, Dixit A. Joubert syndrome diagnosed renally late. Clin Kidney J 2020; 14:1017-1019. [PMID: 33777383 PMCID: PMC7986455 DOI: 10.1093/ckj/sfaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
Joubert syndrome is a genetically heterogeneous multisystem disorder typically diagnosed in childhood. Nephronophthisis is the most common renal pathology in Joubert syndrome, and renal failure usually occurs in childhood or in young adults. We report a 61-year-old female diagnosed with AHI1-related oculorenal Joubert syndrome, who presented initially with decline in renal function in her 50s. Our report describes exceptionally late presentation of renal disease in Joubert syndrome and highlights the importance of continued renal function monitoring in older adults with Joubert syndrome.
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Affiliation(s)
- Elizabeth Collard
- School of Medical Education, Newcastle University, Newcastle upon Tyne, UK
| | - Catherine Byrne
- Department of Nephrology, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London and Moorfields Eye Hospital, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London and Moorfields Eye Hospital, London, UK
| | - Abhijit Dixit
- Department of Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, UK
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Sherer DM, Hsieh V, Muppala R, Granderson F, Dalloul M. Isolated Bilateral Rocker Bottom Feet Associated With 2q13 Microdeletion. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2020; 39:637-638. [PMID: 31520474 DOI: 10.1002/jum.15132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Affiliation(s)
- David M Sherer
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Vicky Hsieh
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Reshma Muppala
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Freda Granderson
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Mudar Dalloul
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
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Whole genome sequencing unveils genetic heterogeneity in optic nerve hypoplasia. PLoS One 2020; 15:e0228622. [PMID: 32040484 PMCID: PMC7010252 DOI: 10.1371/journal.pone.0228622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 01/20/2020] [Indexed: 12/21/2022] Open
Abstract
Optic nerve hypoplasia (ONH) is a congenital malformation with a reduced number of retinal ganglion cell axons in a thin optic nerve. It is a common cause of visual impairment in children and ONH is associated with neurodevelopmental disorders, pituitary hormone deficiencies, and brain malformations. In most cases, the aetiology is unknown, but both environmental factors and genetic causes have been described. This study aimed to identify genetic variants underlying ONH in a well-characterised cohort of individuals with ONH. We performed array comparative genomic hybridization and whole genome sequencing in 29 individuals with ONH. Rare variants were verified by Sanger sequencing and inheritance was assessed in parental samples. We identified 11 rare single nucleotide variants (SNVs) in ten individuals, including a homozygous variant in KIF7 (previously associated with Joubert syndrome), a heterozygous de novo variant in COL4A1 (previously described in an individual with porencephaly), and a homozygous variant in COL4A2. In addition, one individual harboured a heterozygous variant in OPA1 and a heterozygous variant in COL4A1, both were inherited and assessed as variants of unknown clinical significance. Finally, a heterozygous deletion of 341 kb involving exons 7-18 of SOX5 (associated with Lamb-Schaffer syndrome) was identified in one individual. The overall diagnostic yield of pathogenic or likely pathogenic variants in individuals with ONH using whole genome sequencing was 4/29 (14%). Our results show that there is a genetic heterogeneity in ONH and indicate that genetic causes of ONH are not rare. We conclude that genetic testing is valuable in a substantial proportion of the individuals with ONH, especially in cases with non-isolated ONH.
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George A, Cogliati T, Brooks BP. Genetics of syndromic ocular coloboma: CHARGE and COACH syndromes. Exp Eye Res 2020; 193:107940. [PMID: 32032630 DOI: 10.1016/j.exer.2020.107940] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 02/07/2023]
Abstract
Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed.
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Affiliation(s)
- Aman George
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Tiziana Cogliati
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA.
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Cocciadiferro D, Agolini E, Digilio MC, Sinibaldi L, Castori M, Silvestri E, Dotta A, Dallapiccola B, Novelli A. The splice c.1815G>A variant in KIAA0586 results in a phenotype bridging short-rib-polydactyly and oral-facial-digital syndrome: A case report and literature review. Medicine (Baltimore) 2020; 99:e19169. [PMID: 32080096 PMCID: PMC7034684 DOI: 10.1097/md.0000000000019169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION KIAA0586 variants have been associated to short-rib thoracic dysplasia, an autosomal recessive skeletal ciliopathy characterized by a narrow thorax, short limbs, and radiological skeletal abnormalities. PATIENT CONCERNS Patients 1 and 2 were two Roma Gypsy siblings presenting thoracic dysplasia and a combination of oral cavity anomalies. DIAGNOSIS A custom NGS gene panel, including genes associated to skeletal ciliopathies, identified the homozygous KIAA0586 splicing variant c.1815G>A (p.Gln605Gln) in both siblings, confirming the clinical diagnosis of short-rib-polydactyly. INTERVENTION Patients were transferred to neonatal intensive care unit and received life-support treatment. OUTCOMES Patients 1 and 2 died after few hours and 1 month of birth, respectively, because of respiratory failure related with the disease. CONCLUSION We report two patients affected by short-rib polydactyly syndrome and overlapping phenotype with oral-facial-digital syndrome associated with the c.1815G>A variant in KIAA0586, suggesting a quite peculiar genotype-phenotype correlation.
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Affiliation(s)
| | | | | | - Lorenzo Sinibaldi
- Medical Genetics, Department of Pediatrics, Ospedale Pediatrico Bambino Gesù, Rome
| | - Marco Castori
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, San Giovanni Rotondo (Foggia)
| | - Evelina Silvestri
- Division of Pathology, Unit of Fetal and Neonatal Pathology, San Camillo-Forlanini Hospital
| | - Andrea Dotta
- Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital
| | - Bruno Dallapiccola
- Department of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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Bui TPH, Nguyen NT, Ngo VD, Nguyen HN, Ly TTH, Do HD, Huynh MT. Novel compound heterozygous TMEM67 variants in a Vietnamese family with Joubert syndrome: a case report. BMC MEDICAL GENETICS 2020; 21:18. [PMID: 32000717 PMCID: PMC6993522 DOI: 10.1186/s12881-020-0962-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/24/2020] [Indexed: 11/10/2022]
Abstract
Background Joubert syndrome is a genetically heterogeneous autosomal recessive ciliopathy characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles and a deep interpeduncular fossa, known as “molar tooth sign” associated with hypotonia, respiratory control disturbances and abnormal eye movements. To date, pathogenic variants in over 35 genes are known to cause autosomal recessive Joubert Syndrome, while one gene is associated with X-linked recessive inheritance. Case presentation We describe here a non-consanguineous Vietnamese family with Joubert syndrome, a fetus and 10-year-old developmentally delayed boy. Ultrasonography showed ventriculomegaly at 26 + 6 weeks of gestation in the fetus. The 10-year-old-boy was diagnosed with cerebral palsy of unknown origin. Clinical physical examination at the age of 10, he showed clinical features of Joubert syndrome including typical facial dysmorphism, ataxia, severe psychomotor delay, oculomotor apraxia and molar tooth sign on brain MRI. Whole exome sequencing analysis identified a novel compound heterozygous c.725A > G p.Asn242Ser and c.313-3 T > G p.Lys105Valfs*16 TMEM67 variant in the proband and the affected fetus. These two variants were inherited from each parent and confirmed by Sanger sequencing. The variant c.725A > G p.Asn242Ser was previously documented in patients with JS, the novel splice-site c.313-3 T > G p.Lys105Valfs*16 TMEM67 variant produced an aberrant transcript with the loss of four nucleotides of exon 03. Conclusion This study confirms the diagnosis of Joubert syndrome in a Vietnamese family and expands the mutational spectrum of TMEM67 sequence variations. We also highlight the importance of molecular approaches to unravel underlying mechanisms of human genetic disorders. Early precise diagnosis could help provide further accurate genetic counseling for recurrence-risk assessment, future diagnostic option, management as well as treatment guidance for rare disorders.
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Affiliation(s)
- Thi Phuong Hoa Bui
- Medical Genetics Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam
| | - Ngoc Tu Nguyen
- Fetal Medicine Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam
| | - Van Doan Ngo
- Diagnostic Imaging Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam
| | - Hoai-Nghia Nguyen
- Center for Molecular Medicine, University of Medicine and Pharmacy, Ho Chi Minh city, Vietnam
| | - Thi Thanh Ha Ly
- Medical Genetics Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam
| | - Huy Duong Do
- Medical Genetics Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam
| | - Minh-Tuan Huynh
- Medical Genetics Department, Vinmec Times City International Hospital-Times City, HaNoi, Vietnam.
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Nuovo S, Bacigalupo I, Ginevrino M, Battini R, Bertini E, Borgatti R, Casella A, Micalizzi A, Nardella M, Romaniello R, Serpieri V, Zanni G, Valente EM, Vanacore N. Age and sex prevalence estimate of Joubert syndrome in Italy. Neurology 2020; 94:e797-e801. [PMID: 31969461 PMCID: PMC7136056 DOI: 10.1212/wnl.0000000000008996] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/02/2019] [Indexed: 02/03/2023] Open
Abstract
Objective To estimate the prevalence of Joubert syndrome (JS) in Italy applying standards of descriptive epidemiology and to provide a molecular characterization of the described patient cohort. Methods We enrolled all patients with a neuroradiologically confirmed diagnosis of JS who resided in Italy in 2018 and calculated age and sex prevalence, assuming a Poisson distribution. We also investigated the correlation between proband chronological age and age at diagnosis and performed next-generation sequencing (NGS) analysis on probands' DNA when available. Results We identified 284 patients with JS: the overall, female- and male-specific population-based prevalence rates were 0.47 (95% confidence interval [CI] 0.41–0.53), 0.41 (95% CI 0.32–0.49), and 0.53 (95% CI 0.45–0.61) per 100,000 population, respectively. When we considered only patients in the age range from 0 to 19 years, the corresponding population-based prevalence rates rose to 1.7 (95% CI 1.49–1.97), 1.62 (95% CI 1.31–1.99), and 1.80 (95% CI 1.49–2.18) per 100,000 population. NGS analysis allowed identifying the genetic cause in 131 of 219 screened probands. Age at diagnosis was available for 223 probands, with a mean of 6.67 ± 8.10 years, and showed a statistically significant linear relationship with chronological age (r2 = 0.79; p < 0.001). Conclusions We estimated for the first time the age and sex prevalence of JS in Italy and investigated the patients’ genetic profile. The obtained population-based prevalence rate was ≈10 times higher than that available in literature for children population.
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Affiliation(s)
- Sara Nuovo
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Ilaria Bacigalupo
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Monia Ginevrino
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Roberta Battini
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Enrico Bertini
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Renato Borgatti
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Antonella Casella
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Alessia Micalizzi
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Marta Nardella
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Romina Romaniello
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Valentina Serpieri
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Ginevra Zanni
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Enza Maria Valente
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
| | - Nicola Vanacore
- From the Neurogenetics Unit (S.N., M.G., E.M.V.), IRCCS Fondazione Santa Lucia, Rome; Department of Medicine and Surgery (S.N.), University of Salerno; National Center for Disease Prevention and Health Promotion (I.B., N.V.), National Institute of Health, Rome; Department of Molecular Medicine (M.G., A.C., V.S., E.M.V.), University of Pavia; IRCCS Stella Maris Foundation (R. Battini); Department of Clinical and Experimental Medicine (R. Battini), University of Pisa; Laboratory of Molecular Medicine (E.B., M.N., G.Z.), Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, and Laboratory of Medical Genetics (A.M.), IRCCS Bambino Gesù Children's Hospital, Rome; and Neuropsychiatry and Neurorehabilitation Unit (R. Borgatti, R.R.), Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
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Barny I, Perrault I, Michel C, Soussan M, Goudin N, Rio M, Thomas S, Attié-Bitach T, Hamel C, Dollfus H, Kaplan J, Rozet JM, Gerard X. Basal exon skipping and nonsense-associated altered splicing allows bypassing complete CEP290 loss-of-function in individuals with unusually mild retinal disease. Hum Mol Genet 2019; 27:2689-2702. [PMID: 29771326 DOI: 10.1093/hmg/ddy179] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/02/2018] [Accepted: 05/06/2018] [Indexed: 12/18/2022] Open
Abstract
CEP290 mutations cause a spectrum of ciliopathies from Leber congenital amaurosis type 10 (LCA10) to embryo-lethal Meckel syndrome (MKS). Using panel-based molecular diagnosis testing for inherited retinal diseases, we identified two individuals with some preserved vision despite biallelism for presumably truncating CEP290 mutations. The first one carried a homozygous 1 base pair deletion in Exon 17, introducing a premature termination codon (PTC) in Exon 18 (c.1666del; p.Ile556Phefs*17). mRNA analysis revealed a basal exon skipping (BES) of Exon 18, providing mutant cells with the ability to escape protein truncation, while disrupting the reading frame in controls. The second individual harbored compound heterozygous nonsense mutations in Exon 8 (c.508A>T, p.Lys170*) and Exon 32 (c.4090G>T, p.Glu1364*), respectively. Some CEP290 lacking Exon 8 were detected in mutant fibroblasts but not in controls whereas some skipping of Exon 32 occurred in both lines, but with higher amplitude in the mutant. Considering that the deletion of either exon maintains the reading frame in either line, skipping in mutant cells likely involves nonsense-associated altered splicing alone (Exon 8), or with BES (Exon 32). Skipping of PTC-containing exons in mutant cells allowed production of CEP290 isoforms with preserved ability to assemble into a high molecular weight complex and to interact efficiently with proteins important for cilia formation and intraflagellar trafficking. In contrast, studying LCA10 and MKS fibroblasts we show moderate to severe cilia alterations, providing support for a correlation between disease severity and the ability of cells to express shortened, yet functional, CEP290 isoforms.
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Affiliation(s)
- Iris Barny
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Christel Michel
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Mickael Soussan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Nicolas Goudin
- Cell Imaging Core Facility of the Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Imagine and Paris Descartes University, Paris, France
| | - Marlène Rio
- Department of Genetics, IHU Necker-Enfants Malades, University Paris Descartes, Paris, France
| | - Sophie Thomas
- Laboratory of Embryology and Genetics of Human Malformation, INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, Paris, France
| | - Tania Attié-Bitach
- Laboratory of Embryology and Genetics of Human Malformation, INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, Paris, France
| | - Christian Hamel
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, Montpellier, France
| | - Hélène Dollfus
- Centre de Référence pour les Affections Génétiques Ophtalmologiques CARGO, CHRU Strasbourg, INSERM 1112, Université de Strasbourg, Strasbourg, France
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
| | - Xavier Gerard
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases
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Bachmann-Gagescu R, Dempsey JC, Bulgheroni S, Chen ML, D'Arrigo S, Glass IA, Heller T, Héon E, Hildebrandt F, Joshi N, Knutzen D, Kroes HY, Mack SH, Nuovo S, Parisi MA, Snow J, Summers AC, Symons JM, Zein WM, Boltshauser E, Sayer JA, Gunay-Aygun M, Valente EM, Doherty D. Healthcare recommendations for Joubert syndrome. Am J Med Genet A 2019; 182:229-249. [PMID: 31710777 DOI: 10.1002/ajmg.a.61399] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/02/2019] [Accepted: 10/09/2019] [Indexed: 12/19/2022]
Abstract
Joubert syndrome (JS) is a recessive neurodevelopmental disorder defined by a characteristic cerebellar and brainstem malformation recognizable on axial brain magnetic resonance imaging as the "Molar Tooth Sign". Although defined by the neurological features, JS is associated with clinical features affecting many other organ systems, particularly progressive involvement of the retina, kidney, and liver. JS is a rare condition; therefore, many affected individuals may not have easy access to subspecialty providers familiar with JS (e.g., geneticists, neurologists, developmental pediatricians, ophthalmologists, nephrologists, hepatologists, psychiatrists, therapists, and educators). Expert recommendations can enable practitioners of all types to provide quality care to individuals with JS and know when to refer for subspecialty care. This need will only increase as precision treatments targeting specific genetic causes of JS emerge. The goal of these recommendations is to provide a resource for general practitioners, subspecialists, and families to maximize the health of individuals with JS throughout the lifespan.
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Affiliation(s)
- Ruxandra Bachmann-Gagescu
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Institute of Medical Genetics, University of Zurich, Schlieren, Switzerland
| | - Jennifer C Dempsey
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Sara Bulgheroni
- Developmental Neurology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maida L Chen
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Division of Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, Washington
| | - Stefano D'Arrigo
- Developmental Neurology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Ian A Glass
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Theo Heller
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Elise Héon
- Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Friedhelm Hildebrandt
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts
| | - Nirmal Joshi
- Department of Anesthesia, Deaconess Hospital, Evansville, Indiana.,Anesthesia Dynamics, LLC, Evansville, Indiana
| | - Dana Knutzen
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas.,The Children's Hospital of San Antonio, San Antonio, Texas
| | - Hester Y Kroes
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Stephen H Mack
- Joubert Syndrome and Related Disorders Foundation, Petaluma, California
| | - Sara Nuovo
- Neurogenetics Lab, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Melissa A Parisi
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Joseph Snow
- Office of the Clinical Director, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Angela C Summers
- Office of the Clinical Director, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.,Department of Psychology, Fordham University, Bronx, New York
| | - Jordan M Symons
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Division of Nephrology, Seattle Children's Hospital, Seattle, Washington
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Eugen Boltshauser
- Department of Pediatric Neurology (emeritus), Children's University Hospital, Zürich, Switzerland
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Renal Services, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK
| | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland.,Department of Pediatrics and McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Enza Maria Valente
- Neurogenetics Lab, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Dan Doherty
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
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Wheway G, Lord J, Baralle D. Splicing in the pathogenesis, diagnosis and treatment of ciliopathies. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194433. [PMID: 31698098 DOI: 10.1016/j.bbagrm.2019.194433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022]
Abstract
Primary cilia are essential signalling organelles found on the apical surface of epithelial cells, where they coordinate chemosensation, mechanosensation and light sensation. Motile cilia play a central role in establishing fluid flow in the respiratory tract, reproductive tract, brain ventricles and ear. Genetic defects affecting the structure or function of cilia can lead to a broad range of developmental and degenerative diseases known as ciliopathies. Splicing contributes to the pathogenesis, diagnosis and treatment of ciliopathies. Tissue-specific alternative splicing contributes to the tissue-specific manifestation of ciliopathy phenotypes, for example the retinal-specific effects of some genetic defects, due to specific transcript expression in the highly specialised ciliated cells of the retina, the photoreceptor cells. Ciliopathies can arise both as a result of genetic variants in spliceosomal proteins, or as a result of variants affecting splicing of specific cilia genes. Here we discuss the opportunities and challenges in diagnosing ciliopathies using RNA sequence analysis and the potential for treating ciliopathies in a relatively mutation-neutral way by targeting splicing. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Jenny Lord
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Diana Baralle
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland.
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Luo M, Cao L, Cao Z, Ma S, Shen Y, Yang D, Lu C, Lin Z, Liu Z, Yu Y, Cai R, Chen C, Gao H, Wang X, Cao M, Ma X. Whole exome sequencing reveals novel CEP104 mutations in a Chinese patient with Joubert syndrome. Mol Genet Genomic Med 2019; 7:e1004. [PMID: 31625690 PMCID: PMC6900356 DOI: 10.1002/mgg3.1004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 12/22/2022] Open
Abstract
Background Joubert syndrome (JS, OMIM: 213300) is a recessive developmental disorder characterized by cerebellar vermis hypoplasia and a distinctive mid‐hindbrain malformation called the “molar tooth sign” on axial magnetic resonance imaging. To date, more than 35 ciliary genes have been identified as the causative genes of JS. Methods Whole exome sequencing was performed to detect the causative gene mutations in a Chinese patient with JS followed by Sanger sequencing. RT‐PCR and Sanger sequencing were used to confirm the abnormal transcript of centrosomal protein 104 (CEP104, OMIM: 616690). Results We identified two novel heterozygous mutations of CEP104 in the proband, which were c.2364+1G>A and c.414delC (p.Asn138Lysfs*11) (GenBank: NM_014704.3) and consistent with the autosomal recessive inheritance mode. Conclusion Our study reported the fourth case of JS patients with CEP104 mutations, which expands the mutation spectrum of CEP104 and elucidates the clinical heterogeneity of JS.
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Affiliation(s)
- Minna Luo
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Li Cao
- Child Healthcare Department (Child Early Development Center), Sichuan Provincial Hospital for Women and Children, Chengdu, China
| | - Zongfu Cao
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Siyu Ma
- National Research Institute for Family Planning, Beijing, China.,Graduate School of Peking Union Medical College, Beijing, China
| | - Yue Shen
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Di Yang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chao Lu
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Zaisheng Lin
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhimin Liu
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Yufei Yu
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Ruikun Cai
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Cuixia Chen
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Huafang Gao
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Xueyan Wang
- Department of Prenatal Diagnosis, Sichuan Provincial Hospital for Women and Children, Chengdu, China
| | - Muqing Cao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Ma
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
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130
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Pierpont ME, Brueckner M, Chung WK, Garg V, Lacro RV, McGuire AL, Mital S, Priest JR, Pu WT, Roberts A, Ware SM, Gelb BD, Russell MW. Genetic Basis for Congenital Heart Disease: Revisited: A Scientific Statement From the American Heart Association. Circulation 2019; 138:e653-e711. [PMID: 30571578 DOI: 10.1161/cir.0000000000000606] [Citation(s) in RCA: 344] [Impact Index Per Article: 68.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This review provides an updated summary of the state of our knowledge of the genetic contributions to the pathogenesis of congenital heart disease. Since 2007, when the initial American Heart Association scientific statement on the genetic basis of congenital heart disease was published, new genomic techniques have become widely available that have dramatically changed our understanding of the causes of congenital heart disease and, clinically, have allowed more accurate definition of the pathogeneses of congenital heart disease in patients of all ages and even prenatally. Information is presented on new molecular testing techniques and their application to congenital heart disease, both isolated and associated with other congenital anomalies or syndromes. Recent advances in the understanding of copy number variants, syndromes, RASopathies, and heterotaxy/ciliopathies are provided. Insights into new research with congenital heart disease models, including genetically manipulated animals such as mice, chicks, and zebrafish, as well as human induced pluripotent stem cell-based approaches are provided to allow an understanding of how future research breakthroughs for congenital heart disease are likely to happen. It is anticipated that this review will provide a large range of health care-related personnel, including pediatric cardiologists, pediatricians, adult cardiologists, thoracic surgeons, obstetricians, geneticists, genetic counselors, and other related clinicians, timely information on the genetic aspects of congenital heart disease. The objective is to provide a comprehensive basis for interdisciplinary care for those with congenital heart disease.
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131
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Abdelgadir E, Al Sahlawi M, Al Turki L, Khamees K, Ahmed W. Identification of a new homozygous CEP290 gene mutation in a Saudi Family causing joubert syndrome using next-generation sequencing. SAUDI JOURNAL OF KIDNEY DISEASES AND TRANSPLANTATION 2019; 30:964-968. [PMID: 31464256 DOI: 10.4103/1319-2442.265475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 19-year-old female with a learning difficulty, ataxia, and nystagmus was referred to our clinic with advanced chronic kidney disease. Her renal biopsy revealed features of nephronophthisis (NPHP). Magnetic resonance imaging of the brain showed "molar tooth sign." The clinical picture was consistent with Joubert syndrome (JS). Two of her siblings were subsequently found to have a similar condition. Genomic material from the patient, her twin sister, and later on from parents was analyzed for deletion/duplication mutations in the NPHP1 gene using multiplex ligation-dependent probe amplification. No genetic defect was discerned. However, applying the emerging "Next-Generation Sequencing (NGS)" method, we identified a novel c.5704G>T mutation in exon 41 of the CEP290 gene on chromosome 12q21. The identification of this novel mutation, that is, highly likely to be pathogenic was compatible with the diagnosis of JS. This mutation may be included in screening and diagnostic panel. NGS provides an excellent screening method for genetic testing.
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Affiliation(s)
- Elbadri Abdelgadir
- Department of Internal Medicine, King Abdulaziz Hospital, Ministry of National Guard Health Affairs, Al-Ahsa, Saudi Arabia
| | - Muthana Al Sahlawi
- Department of Internal Medicine, College of Medicine, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Lulwah Al Turki
- Department of Internal Medicine, King Abdulaziz Hospital, Ministry of National Guard Health Affairs, Al-Ahsa, Saudi Arabia
| | - Khamess Khamees
- Department of Internal Medicine, King Abdulaziz Hospital, Ministry of National Guard Health Affairs, Al-Ahsa, Saudi Arabia
| | - Wasim Ahmed
- Department of Internal Medicine, King Abdulaziz Hospital, Ministry of National Guard Health Affairs, Al-Ahsa, Saudi Arabia
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132
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Radhakrishnan P, Nayak SS, Shukla A, Lindstrand A, Girisha KM. Meckel syndrome: Clinical and mutation profile in six fetuses. Clin Genet 2019; 96:560-565. [PMID: 31411728 DOI: 10.1111/cge.13623] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 11/30/2022]
Abstract
Meckel syndrome (MKS) is a perinatally lethal, genetically heterogeneous, autosomal recessive condition caused by defective primary cilium formation leading to polydactyly, multiple cysts in kidneys and malformations of nervous system. We performed exome sequencing in six fetuses from six unrelated families with MKS. We identified seven novel variants in B9D2, TNXDC15, CC2D2A, CEP290 and TMEM67. We describe the second family with MKS due to a homozygous variant in B9D2 and fifth family with bi-allelic variant in TXNDC15. Our data validates the causation of MKS by pathogenic variation in B9D2 and TXNDC15 and also adds novel variants in CC2D2A, CEP290 and TMEM67 to the literature.
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Affiliation(s)
- Periyasamy Radhakrishnan
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Shalini S Nayak
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Katta M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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133
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Grochowsky A, Gunay-Aygun M. Clinical characteristics of individual organ system disease in non-motile ciliopathies. TRANSLATIONAL SCIENCE OF RARE DISEASES 2019; 4:1-23. [PMID: 31763176 PMCID: PMC6864414 DOI: 10.3233/trd-190033] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Non-motile ciliopathies (disorders of the primary cilia) include autosomal dominant and recessive polycystic kidney diseases, nephronophthisis, as well as multisystem disorders Joubert, Bardet-Biedl, Alström, Meckel-Gruber, oral-facial-digital syndromes, and Jeune chondrodysplasia and other skeletal ciliopathies. Chronic progressive disease of the kidneys, liver, and retina are common features in non-motile ciliopathies. Some ciliopathies also manifest neurological, skeletal, olfactory and auditory defects. Obesity and type 2 diabetes mellitus are characteristic features of Bardet-Biedl and Alström syndromes. Overlapping clinical features and molecular heterogeneity of these ciliopathies render their diagnoses challenging. In this review, we describe the clinical characteristics of individual organ disease for each ciliopathy and provide natural history data on kidney, liver, retinal disease progression and central nervous system function.
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Affiliation(s)
- Angela Grochowsky
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Department of Pediatrics and The McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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134
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Parisi MA. The molecular genetics of Joubert syndrome and related ciliopathies: The challenges of genetic and phenotypic heterogeneity. ACTA ACUST UNITED AC 2019; 4:25-49. [PMID: 31763177 PMCID: PMC6864416 DOI: 10.3233/trd-190041] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Joubert syndrome (JS; MIM PS213300) is a rare, typically autosomal recessive disorder characterized by cerebellar vermis hypoplasia and a distinctive malformation of the cerebellum and brainstem identified as the “molar tooth sign” on brain MRI. Other universal features include hypotonia with later ataxia and intellectual disability/developmental delay, with additional features consisting of oculomotor apraxia and abnormal respiratory pattern. Notably, other, more variable features include renal cystic disease, typically nephronophthisis, retinal dystrophy, and congenital hepatic fibrosis; skeletal changes such as polydactyly and findings consistent with short-rib skeletal dysplasias are also seen in many subjects. These pleiotropic features are typical of a number of disorders of the primary cilium, and make the identification of causal genes challenging given the significant overlap between JS and other ciliopathy conditions such as nephronophthisis and Meckel, Bardet-Biedl, and COACH syndromes. This review will describe the features of JS, characterize the 35 known genes associated with the condition, and describe some of the genetic conundrums of JS, such as the heterogeneity of founder effects, lack of genotype-phenotype correlations, and role of genetic modifiers. Finally, aspects of JS and related ciliopathies that may pave the way for development of therapeutic interventions, including gene therapy, will be described.
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Affiliation(s)
- Melissa A Parisi
- Chief, Intellectual & Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
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135
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Bachmann‐Gagescu R. A new mouse model for the neurodevelopmental ciliopathy Joubert syndrome. J Pathol 2019; 248:393-395. [DOI: 10.1002/path.5291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 05/13/2019] [Indexed: 11/08/2022]
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136
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Fraser AM, Davey MG. TALPID3 in Joubert syndrome and related ciliopathy disorders. Curr Opin Genet Dev 2019; 56:41-48. [DOI: 10.1016/j.gde.2019.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 05/27/2019] [Accepted: 06/16/2019] [Indexed: 12/18/2022]
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137
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The photoreceptor cilium and its diseases. Curr Opin Genet Dev 2019; 56:22-33. [DOI: 10.1016/j.gde.2019.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/21/2019] [Accepted: 05/11/2019] [Indexed: 12/26/2022]
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138
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Lessieur EM, Song P, Nivar GC, Piccillo EM, Fogerty J, Rozic R, Perkins BD. Ciliary genes arl13b, ahi1 and cc2d2a differentially modify expression of visual acuity phenotypes but do not enhance retinal degeneration due to mutation of cep290 in zebrafish. PLoS One 2019; 14:e0213960. [PMID: 30970040 PMCID: PMC6457629 DOI: 10.1371/journal.pone.0213960] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 03/28/2019] [Indexed: 01/11/2023] Open
Abstract
Mutations in the gene Centrosomal Protein 290 kDa (CEP290) result in multiple ciliopathies ranging from the neonatal lethal disorder Meckel-Gruber Syndrome to multi-systemic disorders such as Joubert Syndrome and Bardet-Biedl Syndrome to nonsyndromic diseases like Leber Congenital Amaurosis (LCA) and retinitis pigmentosa. Results from model organisms and human genetics studies, have suggest that mutations in genes encoding protein components of the transition zone (TZ) and other cilia-associated proteins can function as genetic modifiers and be a source for CEP290 pleiotropy. We investigated the zebrafish cep290fh297/fh297 mutant, which encodes a nonsense mutation (p.Q1217*). This mutant is viable as adults, exhibits scoliosis, and undergoes a slow, progressive cone degeneration. The cep290fh297/fh297 mutants showed partial mislocalization of the transmembrane protein rhodopsin but not of the prenylated proteins rhodopsin kinase (GRK1) or the rod transducin subunit GNB1. Surprisingly, photoreceptor degeneration did not trigger proliferation of Müller glia, but proliferation of rod progenitors in the outer nuclear layer was significantly increased. To determine if heterozygous mutations in other cilia genes could exacerbate retinal degeneration, we bred cep290fh297/fh297 mutants to arl13b, ahi1, and cc2d2a mutant zebrafish lines. While cep290fh297/fh297 mutants lacking a single allele of these genes did not exhibit accelerated photoreceptor degeneration, loss of one alleles of arl13b or ahi1 reduced visual performance in optokinetic response assays at 5 days post fertilization. Our results indicate that the cep290fh297/fh297 mutant is a useful model to study the role of genetic modifiers on photoreceptor degeneration in zebrafish and to explore how progressive photoreceptor degeneration influences regeneration in adult zebrafish.
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Affiliation(s)
- Emma M. Lessieur
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Ping Song
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Gabrielle C. Nivar
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Ellen M. Piccillo
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Joseph Fogerty
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Richard Rozic
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Brian D. Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
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139
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Wheway G, Mitchison HM. Opportunities and Challenges for Molecular Understanding of Ciliopathies-The 100,000 Genomes Project. Front Genet 2019; 10:127. [PMID: 30915099 PMCID: PMC6421331 DOI: 10.3389/fgene.2019.00127] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 02/05/2019] [Indexed: 01/11/2023] Open
Abstract
Cilia are highly specialized cellular organelles that serve multiple functions in human development and health. Their central importance in the body is demonstrated by the occurrence of a diverse range of developmental disorders that arise from defects of cilia structure and function, caused by a range of different inherited mutations found in more than 150 different genes. Genetic analysis has rapidly advanced our understanding of the cell biological basis of ciliopathies over the past two decades, with more recent technological advances in genomics rapidly accelerating this progress. The 100,000 Genomes Project was launched in 2012 in the UK to improve diagnosis and future care for individuals affected by rare diseases like ciliopathies, through whole genome sequencing (WGS). In this review we discuss the potential promise and medical impact of WGS for ciliopathies and report on current progress of the 100,000 Genomes Project, reviewing the medical, technical and ethical challenges and opportunities that new, large scale initiatives such as this can offer.
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Affiliation(s)
- Gabrielle Wheway
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Hannah M. Mitchison
- Genetics and Genomic Medicine, University College London, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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140
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Ott T, Kaufmann L, Granzow M, Hinderhofer K, Bartram CR, Theiß S, Seitz A, Paramasivam N, Schulz A, Moog U, Blum M, Evers CM. The Frog Xenopus as a Model to Study Joubert Syndrome: The Case of a Human Patient With Compound Heterozygous Variants in PIBF1. Front Physiol 2019; 10:134. [PMID: 30858804 PMCID: PMC6397843 DOI: 10.3389/fphys.2019.00134] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/04/2019] [Indexed: 12/16/2022] Open
Abstract
Joubert syndrome (JS) is a congenital autosomal-recessive or—in rare cases–X-linked inherited disease. The diagnostic hallmark of the so-called molar tooth sign describes the morphological manifestation of the mid- and hind-brain in axial brain scans. Affected individuals show delayed development, intellectual disability, ataxia, hyperpnea, sleep apnea, abnormal eye, and tongue movements as well as hypotonia. At the cellular level, JS is associated with the compromised biogenesis of sensory cilia, which identifies JS as a member of the large group of ciliopathies. Here we report on the identification of novel compound heterozygous variants (p.Y503C and p.Q485*) in the centrosomal gene PIBF1 in a patient with JS via trio whole exome sequencing. We have studied the underlying disease mechanism in the frog Xenopus, which offers fast assessment of cilia functions in a number of embryological contexts. Morpholino oligomer (MO) mediated knockdown of the orthologous Xenopus pibf1 gene resulted in defective mucociliary clearance in the larval epidermis, due to reduced cilia numbers and motility on multiciliated cells. To functionally assess patient alleles, mutations were analyzed in the larval skin: the p.Q485* nonsense mutation resulted in a disturbed localization of PIBF1 to the ciliary base. This mutant failed to rescue the ciliation phenotype following knockdown of endogenous pibf1. In contrast, the missense variant p.Y503C resulted in attenuated rescue capacity compared to the wild type allele. Based on these results, we conclude that in the case of this patient, JS is the result of a pathogenic combination of an amorphic and a hypomorphic PIBF1 allele. Our study underscores the versatility of the Xenopus model to study ciliopathies such as JS in a rapid and cost-effective manner, which should render this animal model attractive for future studies of human ciliopathies.
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Affiliation(s)
- Tim Ott
- Institute of Zoology, University of Hohenheim, Stuttgart, Germany
| | - Lilian Kaufmann
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Martin Granzow
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | | | - Claus R Bartram
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Susanne Theiß
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Angelika Seitz
- Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Nagarajan Paramasivam
- Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany.,Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Angela Schulz
- Genomics & Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ute Moog
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Martin Blum
- Institute of Zoology, University of Hohenheim, Stuttgart, Germany
| | - Christina M Evers
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
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141
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Review of Ocular Manifestations of Joubert Syndrome. Genes (Basel) 2018; 9:genes9120605. [PMID: 30518138 PMCID: PMC6315342 DOI: 10.3390/genes9120605] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/13/2018] [Accepted: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
Joubert syndrome is a group of rare disorders that stem from defects in a sensory organelle, the primary cilia. Affected patients often present with disorders involving multiple organ systems, including the brain, eyes, and kidneys. Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with a diagnostic “molar tooth” sign observed by magnetic resonance imaging (MRI) of the midbrain. We reviewed the ocular phenotypes that can be found in patients with Joubert syndrome. Ocular motor apraxia is the most frequent (80% of patients), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Although mutations in 34 genes have been found to be associated with Joubert syndrome, retinal degeneration has been reported in only 38% of patients. Mutations in AHI1 and CEP290, genes critical to primary cilia function, have been linked to retinal degeneration. In conclusion, Joubert syndrome is a rare pleiotropic group of disorders with variable ocular presentations.
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142
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Boczek NJ, Hopp K, Benoit L, Kraft D, Cousin MA, Blackburn PR, Madsen CD, Oliver GR, Nair AA, Na J, Bianchi DW, Beek G, Harris PC, Pichurin P, Klee EW. Characterization of three ciliopathy pedigrees expands the phenotype associated with biallelic C2CD3 variants. Eur J Hum Genet 2018; 26:1797-1809. [PMID: 30097616 PMCID: PMC6244354 DOI: 10.1038/s41431-018-0222-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/14/2018] [Accepted: 06/26/2018] [Indexed: 11/09/2022] Open
Abstract
Whole exome sequencing (WES) is utilized in diagnostic odyssey cases to identify the underlying genetic cause associated with complex phenotypes. Recent publications suggest that WES reveals the genetic cause in ~25% of these cases and is most successful when applied to children with neurological disease. The residual 75% of cases remain genetically elusive until more information becomes available in the literature or functional studies are pursued. WES performed on three families with presumed ciliopathy diagnoses, including orofaciodigital (OFD) syndrome, fetal encephalocele, or Joubert-related disorder, identified compound heterozygous variants in C2CD3. Biallelic variants in C2CD3 have previously been associated with ciliopathies, including OFD syndrome type 14 (OFD14; MIM: 615948). As three of the six identified variants were predicted to affect splicing, exon-skipping analysis using either RNA sequencing or PCR-based methods were completed to determine the pathogenicity of these variants, and showed that each of the splicing variants led to a frameshifted protein product. Using these studies in combination with the 2015 ACMG guidelines, each of the six identified variants were classified as either pathogenic or likely pathogenic, and are therefore likely responsible for our patients' phenotypes. Each of the families had a distinct clinical phenotype and severity of disease, extending from lethal to viable. These findings highlight that there is a broad phenotypic spectrum associated with C2CD3-mediated disease and not all patients present with the typical features of OFD14.
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Affiliation(s)
- Nicole J Boczek
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Katharina Hopp
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO, USA
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Lacey Benoit
- Division of Medical Genetics, Royal University Hospital, Saskatoon, Canada
| | - Daniel Kraft
- Department of Biochemical Genetics, Mayo Clinic, Rochester, MN, USA
| | - Margot A Cousin
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Patrick R Blackburn
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Charles D Madsen
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Gavin R Oliver
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Asha A Nair
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Jie Na
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Diana W Bianchi
- Department of Pediatrics, Obstetrics & Gynecology, Tufts University, School of Medicine, Boston, MA, USA
| | - Geoffrey Beek
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Pavel Pichurin
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA.
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
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143
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Diagnosis of Joubert Syndrome 10 in a Fetus with Suspected Dandy-Walker Variant by WES: A Novel Splicing Mutation in OFD1. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4032543. [PMID: 30581852 PMCID: PMC6276521 DOI: 10.1155/2018/4032543] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/09/2018] [Accepted: 10/29/2018] [Indexed: 11/17/2022]
Abstract
Joubert syndrome (JBTS) is a clinically and genetically heterogeneous group of ciliary diseases. To date, 34 subtypes of JBTS have been classified due to different causative genes or extra clinical features. Most of them are autosomal recessive, while only the subtype 10 (JBTS10) is a quite rare X-linked recessive disorder caused by OFD1 mutations with few reports. In this study, by using whole exome sequencing (WES), a novel OFD1 splicing mutation (c.2488+2T>C) was identified in a male fetus with suspected Dandy-Walker variant (DWV) and syndactyly, for whom abnormal karyotype and pathogenic CNV have been excluded. This mutation was inherited from the mother who has experienced two similar pregnancies before. An abnormal skipping of exon 18 in OFD1 mRNA was confirmed by RT-PCR and sequencing. Result from quantitative RT-PCR also showed that total OFD1 mRNA in the index fetus was significantly lower than the control. After a combined analysis of genetic testing results and genotype-phenotype correlations, the novel mutation c.2488+2T>C in OFD1 was considered to be the genetic cause for the affected fetus. Thus the diagnosis should be JBTS10 rather than the primary clinical diagnosis of DWV. We report the first prenatal case of JBTS10 in Chinese population, which not only helps the family to predict recurrence risks for future pregnancies but also provides more information for understanding such a rare disease. The results also present evidence that WES is an effective method in prenatal diagnosis for those fetuses with Joubert syndrome.
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144
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Mégarbané A, Hmaimess G, Bizzari S, El-Bazzal L, Al-Ali MT, Stora S, Delague V, El-Hayek S. A novel PDE6D mutation in a patient with Joubert syndrome type 22 (JBTS22). Eur J Med Genet 2018; 62:103576. [PMID: 30423442 DOI: 10.1016/j.ejmg.2018.11.010] [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: 03/20/2018] [Revised: 10/02/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Abstract
Joubert syndrome (JS) is an autosomal or X-linked recessive syndrome principally characterized by hypotonia, ataxia, cognitive impairment, and a specific finding on brain imaging called a "molar tooth sign" (MTS), which can be isolated or in conjunction with variable organ involvement. The genetic basis of JS is heterogeneous, with over 35 ciliary genes being implicated in its pathogenesis. However, some of these genes (such as PDE6D) have been associated to JS only in single families, seeking confirmation. Here we report a boy, born to first cousin parents, presenting with developmental delay, hypotonia, microcephaly, post axial polydactyly, oculomotor apraxia, and MTS. Whole exome sequencing revealed the presence of a novel homozygous truncating variant in the PDE6D gene: NM_002601.3:c.367_368insG [p.(Leu123Cysfs*13)]. The variant was confirmed by Sanger sequencing and found at the heterozygous state in both parents. A review of the literature pertaining to the role of PDE6D in JS is discussed.
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Affiliation(s)
| | | | - Sami Bizzari
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Lara El-Bazzal
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France
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145
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The complexity of the cilium: spatiotemporal diversity of an ancient organelle. Curr Opin Cell Biol 2018; 55:139-149. [PMID: 30138887 DOI: 10.1016/j.ceb.2018.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 02/06/2023]
Abstract
Cilia are microtubule-based appendages present on almost all vertebrate cell types where they mediate a myriad of cellular processes critical for development and homeostasis. In humans, impaired ciliary function is associated with an ever-expanding repertoire of phenotypically-overlapping yet highly variable genetic disorders, the ciliopathies. Extensive work to elucidate the structure, function, and composition of the cilium is offering hints that the `static' representation of the cilium is a gross oversimplification of a highly dynamic organelle whose functions are choreographed dynamically across cell types, developmental, and homeostatic contexts. Understanding this diversity will require discerning ciliary versus non-ciliary roles for classically-defined `ciliary' proteins; defining ciliary protein-protein interaction networks within and beyond the cilium; and resolving the spatiotemporal diversity of ciliary structure and function. Here, focusing on one evolutionarily conserved ciliary module, the intraflagellar transport system, we explore these ideas and propose potential future studies that will improve our knowledge gaps of the oversimplified cilium and, by extension, inform the reasons that underscore the striking range of clinical pathologies associated with ciliary dysfunction.
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146
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Pauli S, Altmüller J, Schröder S, Ohlenbusch A, Dreha-Kulaczewski S, Bergmann C, Nürnberg P, Thiele H, Li Y, Wollnik B, Brockmann K. Homozygosity for the c.428delG variant in KIAA0586 in a healthy individual: implications for molecular testing in patients with Joubert syndrome. J Med Genet 2018; 56:261-264. [DOI: 10.1136/jmedgenet-2018-105470] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/02/2018] [Accepted: 08/02/2018] [Indexed: 11/03/2022]
Abstract
BackgroundJoubert syndrome (JBTS) is a rare neurodevelopmental disorder with marked phenotypic variability and genetic heterogeneity. Homozygous or compound heterozygous mutations in the KIAA0586 gene on chromosome 14q23 are known to be associated with JBTS-23. The frameshift variant c.428delG is the most frequent KIAA0586 variant reported in JBTS-23; yet, homozygosity of this variant was observed in two patients with JBTS-23. However, homozygosity of the c.428delG variant was recently reported as well in one healthy individual.ObjectiveTo clarify whether the frameshift variant c.428delG in KIAA0586 is pathogenic in the homozygous state.MethodsWhole-exome sequencing as well as RNA analysis were performed.ResultsWe identified biallelic mutations, including the variant c.428delG and a splice site variant c.1413–1G>C, in KIAA0586 in two siblings with clinical and MRI features of JBTS. The c.1413–1G>C variant was inherited from the healthy father. The c.428delG variant was found in the healthy mother in a homozygous state in blood lymphocytes, hair root cells and buccal epithelial cells. RNA analysis revealed that the transcript harbouring the c.428delG variant was expressed in blood cells from the healthy mother, indicating that transcripts harbouring this variant elude the mechanism of nonsense-mediated mRNA decay.ConclusionConsidering this and the high allele frequency of 0.003117 in the gnomAD database, we conclude that c.428delG represents a JBTS disease-causing variant only if present in compound heterozygous state with a more severe KIAA0586 variant, but not in a homozygous situation.
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Brooks BP, Zein WM, Thompson AH, Mokhtarzadeh M, Doherty DA, Parisi M, Glass IA, Malicdan MC, Vilboux T, Vemulapalli M, Mullikin JC, Gahl WA, Gunay-Aygun M. Joubert Syndrome: Ophthalmological Findings in Correlation with Genotype and Hepatorenal Disease in 99 Patients Prospectively Evaluated at a Single Center. Ophthalmology 2018; 125:1937-1952. [PMID: 30055837 DOI: 10.1016/j.ophtha.2018.05.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 05/25/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Joubert syndrome (JS) is caused by mutations in >34 genes that encode proteins involved with primary (nonmotile) cilia and the cilium basal body. This study describes the varying ocular phenotypes in JS patients, with correlation to systemic findings and genotype. DESIGN Patients were systematically and prospectively examined at the National Institutes of Health (NIH) Clinical Center in the setting of a dedicated natural history clinical trial. PARTICIPANTS Ninety-nine patients with JS examined at a single center. METHODS All patients underwent genotyping for JS, followed by complete age-appropriate ophthalmic examinations at the NIH Clinical Center, including visual acuity (VA), fixation behavior, lid position, motility assessment, slit-lamp biomicroscopy, dilated fundus examination with an indirect ophthalmoscope, and retinoscopy. Color and fundus autofluorescence imaging, Optos wide-field photography (Dunfermline, Scotland, UK), and electroretinography (ERG) were performed when possible. MAIN OUTCOME MEASURES The VA (with longitudinal follow-up where possible), ptosis, extraocular muscle function, retinal and optic nerve status, and retinal function as measured by ERG. RESULTS Among patients with JS with quantifiable VA (68/99), values ranged from 0 logarithm of the minimum angle of resolution (logMAR) (Snellen 20/20) to 1.5 logMAR (Snellen 20/632). Strabismus (71/98), nystagmus (66/99), oculomotor apraxia (60/77), ptosis (30/98), coloboma (28/99), retinal degeneration (20/83), and optic nerve atrophy (8/86) were identified. CONCLUSIONS We recommend regular monitoring for ophthalmological manifestations of JS beginning soon after birth or diagnosis. We demonstrate delayed visual development and note that the amblyogenic time frame may last significantly longer in JS than is typical. In general, patients with coloboma were less likely to display retinal degeneration, and those with retinal degeneration did not have coloboma. Severe retinal degeneration that is early and aggressive is seen in disease caused by specific genes, such as CEP290- and AHI1-associated JS. Retinal degeneration in INPP5E-, MKS1-, and NPHP1-associated JS was generally milder. Finally, ptosis surgery can be helpful in a subset of patients with JS; decisions as to timing and benefit/risk ratio need to be made on an individual basis according to expert consultation.
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Affiliation(s)
- Brian P Brooks
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland; National Human Genome Research Institute, Genetics and Molecular Biology Branch, Bethesda, Maryland; Office of the Clinical Director, National Eye Institute, National Institutes of Health, Bethesda, Maryland.
| | - Wadih M Zein
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Amy H Thompson
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland; Columbus Technologies & Services, Inc., Greenbelt, Maryland
| | - Maryam Mokhtarzadeh
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Daniel A Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Melissa Parisi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Ian A Glass
- Department of Pediatrics, University of Washington, Seattle, Washington; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - May C Malicdan
- National Institutes of Health Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, Maryland; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Thierry Vilboux
- National Human Genome Research Institute, Genetics and Molecular Biology Branch, Bethesda, Maryland; Inova Translational Medicine Institute, Falls Church, Virginia
| | - Meghana Vemulapalli
- National Institutes of Health Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - James C Mullikin
- National Institutes of Health Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Gahl
- National Institutes of Health Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, Maryland; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland; Johns Hopkins University School of Medicine, Department of Pediatrics and McKusick-Nathans Institute of Genetic Medicine, Baltimore, Maryland
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148
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Macular staphyloma in patients affected by Joubert syndrome with retinal dystrophy: a new finding detected by SD-OCT. Doc Ophthalmol 2018; 137:25-36. [PMID: 29987673 DOI: 10.1007/s10633-018-9646-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 05/30/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE Joubert syndrome (JS) is an inherited autosomal recessive or X-lined disorder characterized by a congenital malformation of the mid-hindbrain and a large spectrum of clinical features. It is estimated that retinal dystrophy is present in association with the typical neurological findings in about one-third of the patients. The aim of this study is to better characterize the macular region in JS patients with and without retinal dystrophy. METHODS We describe six individuals affected by JS as demonstrated by the presence of the typical "molar tooth sign" on MRI. The presence of retinal dystrophy was assessed by fundus examination and electrophysiology by means of full-field electroretinogram (ERG) and visual evoked potentials (VEP) at five spatial frequencies (300-15 min of arc). The macular region was examined with spectral domain optical coherence tomography (SD-OCT). All the exams were performed in awake conditions. All the patients underwent next-generation-sequencing analysis of known JS genes. RESULTS Pathogenic biallelic variants in either the INPP5E gene or the AHI1 gene were detected in two pairs of siblings, all positive for retinal dystrophy. Genetic testing yielded no results in the remaining two patients, one with bilateral coloboma and retinal dystrophy and the other with normal fundus appearance. Decimal best-corrected visual acuity was between 0.1 and 1.0. In the two pairs of siblings, SD-OCT revealed a posterior staphyloma centred on the fovea, in one case associated with cystoid macular oedema. Macular morphology was just slightly altered in the fifth patient and completely normal in the last patient. Refractive error was between + 2.50 diopter sphere (DS) and - 8 DS and - 4 diopter cylinder ax 45°. ERG waves were markedly lower than the normal limits in both scotopic and photopic components in the two pairs of siblings and in the fifth subject, with VEP P100 latencies and amplitudes delayed and reduced in all spatial frequencies. ERG and VEP were within normal limits in the last patient. CONCLUSIONS To our knowledge, macular staphyloma has not been described before in JS. Further work is warranted to assess the true prevalence of staphyloma in JS and its connection to retinal dystrophy.
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Prenatal Diagnosis and Genetic Analysis of a Fetus with Joubert Syndrome. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7202168. [PMID: 29955609 PMCID: PMC6000882 DOI: 10.1155/2018/7202168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/06/2018] [Indexed: 12/31/2022]
Abstract
Objective To diagnose and explore the genetic cause of Joubert syndrome (JS) in a fetus. Methods Prenatal ultrasound and magnetic resonance imaging (MRI) examinations were performed, and genetic analysis was conducted using targeted next-generation sequencing (NGS) and Sanger sequencing. Results Prenatal ultrasound and MRI examinations showed cerebellar vermis hypoplasia and molar tooth sign (MTS); hence the fetus was diagnosed with JS. Further genetic analysis revealed a known missense variant (c.3599C>T, p.A1200V) and a novel missense variant (c.3857G>A, p.R1286H) in the C5orf42 gene of the fetus. Conclusion Our study provides insights into prenatal and early diagnosis of JS and expands the variation spectrum of C5orf42 gene.
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Wang B, Zhang Y, Dong H, Gong S, Wei B, Luo M, Wang H, Wu X, Liu W, Xu X, Zheng Y, Sun M. Loss of Tctn3 causes neuronal apoptosis and neural tube defects in mice. Cell Death Dis 2018; 9:520. [PMID: 29725084 PMCID: PMC5938703 DOI: 10.1038/s41419-018-0563-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022]
Abstract
Tctn3 belongs to the Tectonic (Tctn) family and is a single-pass membrane protein localized at the transition zone of primary cilia as an important component of ciliopathy-related protein complexes. Previous studies showed that mutations in Tctn1 and Tctn2, two members of the tectonic family, have been reported to disrupt neural tube development in humans and mice, but the functions of Tctn3 in brain development remain elusive. In this study, Tctn3 knockout (KO) mice were generated by utilizing the piggyBac (PB) transposon system. We found that Tctn3 KO mice exhibited abnormal global development, including prenatal lethality, microphthalmia, polysyndactyly, and abnormal head, sternum, and neural tube, whereas Tctn3 heterozygous KO mice did not show abnormal development or behaviors. Further, we found that the mRNA levels of Gli1 and Ptch1, downstream signaling components of the Shh pathway, were significantly reduced. Likewise, neural tube patterning-related proteins, such as Shh, Foxa2, and Nkx2.2, were altered in their distribution. Interestingly, Tctn3 KO led to significant changes in apoptosis-related proteins, including Bcl-2, Bax, and cleaved PARP1, resulting in reduced numbers of neuronal cells in embryonic brains. Tctn3 KO inhibited the PI3K/Akt signaling pathway but not the mTOR-dependent pathway. The small molecule SC79, a specific Akt activator, blocked apoptotic cell death in primary mouse embryonic fibroblasts from Tctn3 KO mice. Finally, NPHP1, a protein with anti-apoptotic ability, was found to form a complex with Tctn3, and its levels were decreased in Tctn3 KO mice. In conclusion, our results show that Tctn3 KO disrupts the Shh signaling pathway and neural tube patterning, resulting in abnormal embryonic development, cellular apoptosis, and prenatal death in mice.
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Affiliation(s)
- Bin Wang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Yingying Zhang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Hongli Dong
- Department of Neurology, Suzhou Hospital of Traditional Chinese Medicine, Suzhou City, 215123, Jiangsu, China
| | - Siyi Gong
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Bin Wei
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Man Luo
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China.,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xiaohui Wu
- State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China.,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China
| | - Wei Liu
- Department of Pathology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Xingshun Xu
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China.
| | - Yufang Zheng
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China. .,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China. .,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China.
| | - Miao Sun
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.
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