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Kim HM, Jo HS, Han JY, Choi IS, Song MK, Park HK. Joubert syndrome presenting bilateral peroneal neuropathies: A case report. Medicine (Baltimore) 2024; 103:e37987. [PMID: 38669389 PMCID: PMC11049732 DOI: 10.1097/md.0000000000037987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
RATIONALE Joubert syndrome (JS) is a rare genetic disorder that presents with various neurological symptoms, primarily involving central nervous system dysfunction. Considering the etiology of JS, peripheral nervous system abnormalities cannot be excluded; however, cases of JS accompanied by peripheral nervous system abnormalities have not yet been reported. Distinct radiological findings on brain magnetic resonance imaging were considered essential for the diagnosis of JS. However, recently, cases of JS with normal or nearly normal brain morphology have been reported. To date, there is no consensus on the most appropriate diagnostic method for JS when imaging-based diagnostic approach is challenging. This report describes the case of an adult patient who exhibited bilateral peroneal neuropathies and was finally diagnosed with JS through genetic testing. PATIENT CONCERNS AND DIAGNOSIS A 27-year-old man visited our outpatient clinic due to a gait disturbance that started at a very young age. The patient exhibited difficulty maintaining balance, especially when walking slowly. Oculomotor apraxia was observed on ophthalmic evaluation. During diagnostic workups, including brain imaging and direct DNA sequencing, no conclusive findings were detected. Only nerve conduction studies revealed profound bilateral peroneal neuropathies. We performed whole genome sequencing to obtain a proper diagnosis and identify the gene mutation responsible for JS. LESSONS This case represents the first instance of peripheral nerve dysfunction in JS. Further research is needed to explore the association between JS and peripheral nervous system abnormalities. Detailed genetic testing may serve as a valuable tool for diagnosing JS when no prominent abnormalities are detected in brain imaging studies.
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Affiliation(s)
- Hyeong-Min Kim
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - Hyun-Seok Jo
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - Jae-Young Han
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - In-Sung Choi
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - Min-Keun Song
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - Hyeng-Kyu Park
- Department of Physical and Rehabilitation Medicine, Research Institute of Medical Sciences, Heart Research Center, Chonnam National University, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
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Dong Y, Zhang K, Yao H, Jia T, Wang J, Zhu D, Xu F, Cheng M, Zhao S, Shi X. Clinical and genetic characteristics of 36 children with Joubert syndrome. Front Pediatr 2023; 11:1102639. [PMID: 37547106 PMCID: PMC10401045 DOI: 10.3389/fped.2023.1102639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/10/2023] [Indexed: 08/08/2023] Open
Abstract
Background and aims Joubert syndrome (JBTS, OMIM # 213300) is 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 diagnosing JBTS. It is a clinically and genetically heterogeneous disorder involving mutations in more than 40 ciliopathy-related genes. However, long-term follow-up data are scarce, and further research is needed to determine the abundant phenotypes and genetics of this disorder. The study aimed to summarize clinical manifestations, particular appearance on cranial imaging, genetic data, and prognostic features of patients with JBTS. Methods A retrospective case review of 36 cases of JBTS from May 1986 to December 2021 was performed. Clinical data of JBTS patients with development retardation and molar tooth sign on cranial imaging as the main features were analyzed. Genetic testing was performed according to consent obtained from patients and their families. The Gesell Developmental Scale was used to evaluate the intelligence level before and after treatment. The children were divided into a purely neurological JBTS (pure JBTS) group and JBTS with multi-organ system involvement group and then followed up every 3-6 months. Results We enrolled 18 males and 18 females. Thirty-four (94.44%) cases had developmental delay, one patient (2.78%) had strabismus, and one patient (2.78%) had intermittent dizziness. There was one case co-morbid with Lesch-Nyhan syndrome. Three-quarters of cases had one or more other organ or system involvement, with a greater predilection for vision and hearing impairment. JBTS could also involve the skin. Thirty-one cases (86.11%) showed a typical molar tooth sign, and five cases showed a bat wing sign on cranial imaging. Abnormal video electroencephalogram (VEEG) result was obtained in 7.69% of cases. We found six JBTS-related novel gene loci variants: CPLANE1: c.4189 + 1G > A, c.3101T > C(p.Ile1034Thr), c.3733T > C (p.Cys1245Arg), c.4080G > A(p.Lys1360=); RPGRIP1l: c.1351-11A > G; CEP120: c.214 C > T(p.Arg72Cys). The CHD7 gene may be potentially related to the occurrence of JBTS. Analysis showed that the prognosis of pure JBTS was better than that of JBTS with neurological and non-neurological involvement after the formal rehabilitation treatment (P < 0.05). Of the three children with seizures, two cases had epilepsy with a poor prognosis, and another case had breath-holding spells. Conclusion Our findings indicate that early cranial imaging is helpful for the etiological diagnosis of children with unexplained developmental delay and multiple malformations. Patients with JBTS may have coexisting skin abnormalities. The novel gene loci of CPLANE1, RPGRIP1l, and CEP120 were associated with JBTS in our study and provided significant information to enrich the related genetic data. Future works investigating several aspects of the association between CHD7 gene and JBTS merit further investigation. The prognosis of children with pure JBTS is better than that of children with JBTS with non-neurological involvement.
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Affiliation(s)
- Yan Dong
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Ke Zhang
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - He Yao
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Tianming Jia
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jun Wang
- Department of Children Rehabilitation, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Dengna Zhu
- Department of Children Rehabilitation, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Falin Xu
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Meiying Cheng
- Department of Radiology, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shichao Zhao
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoyi Shi
- Department of Pediatric Development and Behavior, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Martínez-Granero F, Martínez-Cayuelas E, Rodilla C, Núñez-Moreno G, Rodríguez de Alba M, Blanco-Kelly F, Romero R, Minguez P, Ayuso C, Lorda-Sanchez I, Corton M, Almoguera B. Biallelic intragenic tandem duplication of CPLANE1 in Joubert syndrome: A case report. Clin Genet 2023; 103:448-452. [PMID: 36719180 DOI: 10.1111/cge.14306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 02/01/2023]
Abstract
Joubert syndrome (JS) is a clinically and genetically heterogeneous genetic disorder. To date, 40 JS-causing genes have been reported and CPLANE1 is one of the most frequently mutated, with biallelic pathogenic missense and truncating variants explaining up to 14% of JS cases. We present a case of JS diagnosed after the identification of a novel biallelic intragenic duplication of exons 20-46 of CPLANE1. The quadruplication was identified by short-read sequencing and copy number variant analysis and confirmed in tandem by long PCR with the breakpoints defined by a nanopore-based long-read sequencing approach. Based on the genetic findings and the clinical presentation of the patient, a brain MRI was ordered, evidencing the molar tooth sign, which confirmed the diagnosis of JS in the patient. This is, to the best of our knowledge, the first report of an intragenic duplication in this gene as the potential molecular mechanism of JS.
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Affiliation(s)
| | | | - Cristina Rodilla
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Bioinformatics Unit, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
| | - Marta Rodríguez de Alba
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Raquel Romero
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Bioinformatics Unit, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
| | - Pablo Minguez
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Bioinformatics Unit, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Isabel Lorda-Sanchez
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Marta Corton
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Berta Almoguera
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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Stroscio G, Cuppari C, Ceravolo MD, Salpietro A, Battaglia F, Sallemi A, Fusco M, Ceravolo A, Iapadre G, Calì E, Impollonia D, Granata F. Radiological Features of Joubert's Syndrome. JOURNAL OF PEDIATRIC NEUROLOGY 2023. [DOI: 10.1055/s-0042-1760241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AbstractJoubert syndrome (JS) is a rare autosomal recessive disorder. All patients affected by this syndrome presented a characteristic picture of cranial fossa malformations, called “molar tooth sign.” This sign is defined by the presence in axial section at the level of a deck/midbrain, of hypo/dysplasia of the cerebellar vermis, abnormally deep interpeduncular fossa and horizontalized thickened and elongated superior cerebellar peduncles. Although “molar tooth sign” is peculiar of JS, other radiological findings have been also reported in these patients. Here, the authors briefly assumed the principal magnetic resonance imaging findings of JS.
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Affiliation(s)
- Giovanni Stroscio
- Unit of Radiology, Department of Human Pathology in Adulthood and Childhood “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Caterina Cuppari
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Maria Domenica Ceravolo
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | | | - Francesco Battaglia
- Orthopaedic and Traumatology Department, “S. Anna” Hospital, University of Ferrara, Ferrara, Italy
| | - Alessia Sallemi
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Monica Fusco
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | | | - Giulia Iapadre
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - Elisa Calì
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Daniela Impollonia
- Unit of Radiology, Department of Human Pathology in Adulthood and Childhood “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Francesca Granata
- Unit of Radiology, Department of Human Pathology in Adulthood and Childhood “G. Barresi,” University Hospital of Messina, Messina, Italy
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Matoba K, Chihara N, Satake W, Tokuoka H, Otsuka Y, Ueda T, Sekiguchi K, Itoh M, Matsumoto R. Long-Surviving Adult Siblings With Joubert Syndrome Harboring a Novel Compound Heterozygous CPLANE1 Variant. Neurol Genet 2022; 8:e200031. [PMID: 36176335 PMCID: PMC9513979 DOI: 10.1212/nxg.0000000000200031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 07/26/2022] [Indexed: 12/03/2022]
Abstract
Background and Objectives We describe 2 long-surviving siblings with a mild phenotype of Joubert syndrome (JBTS) harboring a novel compound heterozygous missense variant in the CPLANE1 gene. Methods Targeted sequencing data of 2 middle-aged siblings (sister and brother) with JBTS were analyzed. Results The patients were older than 60 years and presented with an inborn facial anomaly and ataxia, accompanied by a molar tooth sign on brain MRI. The male patient showed mild intellectual disability, abnormal eye movements, and progressive gait disturbance. Targeted sequencing revealed a compound heterozygous missense variant of CPLANE1 p.Arg1193Cys_Gln1223Pro; c.3577C>T_3668A>C. Multiple in silico assays predicted that the missense sites were pathogenic. Discussion The phenotype-genotype correlation of CPLANE1 remains controversial, although many cases have been previously reported in children and young adults. Our study revealed a novel pathogenic variant of CPLANE1 in patients, confirming the role of this gene in JBTS, thus providing an opportunity for neurologists to recognize JBTS as a differential diagnosis for chronic progressive ataxia in an aging society.
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Serpieri V, D’Abrusco F, Dempsey JC, Cheng YHH, Arrigoni F, Baker J, Battini R, Bertini ES, Borgatti R, Christman AK, Curry C, D'Arrigo S, Fluss J, Freilinger M, Gana S, Ishak GE, Leuzzi V, Loucks H, Manti F, Mendelsohn N, Merlini L, Miller CV, Muhammad A, Nuovo S, Romaniello R, Schmidt W, Signorini S, Siliquini S, Szczałuba K, Vasco G, Wilson M, Zanni G, Boltshauser E, Doherty D, Valente EM. SUFU haploinsufficiency causes a recognisable neurodevelopmental phenotype at the mild end of the Joubert syndrome spectrum. J Med Genet 2022; 59:888-894. [PMID: 34675124 PMCID: PMC9411896 DOI: 10.1136/jmedgenet-2021-108114] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/29/2021] [Indexed: 01/25/2023]
Abstract
BACKGROUND Joubert syndrome (JS) is a recessively inherited ciliopathy characterised by congenital ocular motor apraxia (COMA), developmental delay (DD), intellectual disability, ataxia, multiorgan involvement, and a unique cerebellar and brainstem malformation. Over 40 JS-associated genes are known with a diagnostic yield of 60%-75%.In 2018, we reported homozygous hypomorphic missense variants of the SUFU gene in two families with mild JS. Recently, heterozygous truncating SUFU variants were identified in families with dominantly inherited COMA, occasionally associated with mild DD and subtle cerebellar anomalies. METHODS We reanalysed next generation sequencing (NGS) data in two cohorts comprising 1097 probands referred for genetic testing of JS genes. RESULTS Heterozygous truncating and splice-site SUFU variants were detected in 22 patients from 17 families (1.5%) with strong male prevalence (86%), and in 8 asymptomatic parents. Patients presented with COMA, hypotonia, ataxia and mild DD, and only a third manifested intellectual disability of variable severity. Brain MRI showed consistent findings characterised by vermis hypoplasia, superior cerebellar dysplasia and subtle-to-mild abnormalities of the superior cerebellar peduncles. The same pattern was observed in two out of three tested asymptomatic parents. CONCLUSION Heterozygous truncating or splice-site SUFU variants cause a novel neurodevelopmental syndrome encompassing COMA and mild JS, which likely represent overlapping entities. Variants can arise de novo or be inherited from a healthy parent, representing the first cause of JS with dominant inheritance and reduced penetrance. Awareness of this condition will increase the diagnostic yield of JS genetic testing, and allow appropriate counselling about prognosis, medical monitoring and recurrence risk.
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Affiliation(s)
| | - Fulvio D’Abrusco
- Department of Molecular Medicine, University of Pavia, Pavia, Lombardia, Italy
| | - Jennifer C Dempsey
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA
| | - Yong-Han Hank Cheng
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA
| | - Filippo Arrigoni
- Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Janice Baker
- Genomics and Genetic Medicine Department, Children's Minnesota, Minneapolis, Minnesota, USA
| | - Roberta Battini
- Unit of Child Neuropsychiatry, IRCCS Foundation Stella Maris, Calambrone, Toscana, Italy,Department of Clinical ad Experimental Medicine, University of Pisa, Pisa, Italy
| | - Enrico Silvio Bertini
- Laboratory of Molecular Medicine, Unit of Muscular and Neurodegenerative Diseases, Department of Neuroscience, Bambino Gesu Children's Hospital, IRCCS, Rome, Italy
| | - Renato Borgatti
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy,Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Angela K Christman
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA
| | - Cynthia Curry
- Department of Pediatrics, Stanford University, Stanford, California, USA,Division of Medical Genetics, Department of Pediatrics, University of California San Francisco, Fresno, California, USA,University Pediatric Specialists, Fresno, California, USA
| | - Stefano D'Arrigo
- Department of Developmental Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Joel Fluss
- Department of Women, Children and Adolescents, Geneva University Hospitals, Geneva, Switzerland
| | - Michael Freilinger
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Simone Gana
- Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - Gisele E Ishak
- Department of Neuroradiology, University of Washington School of Medicine, Seattle, Washington, USA,Pediatric Radiology, Seattle Children’s Hospital, Seattle, Washington, USA
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, University of Rome La Sapienza, Roma, Lazio, Italy
| | - Hailey Loucks
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA
| | - Filippo Manti
- Department of Human Neuroscience, University of Rome La Sapienza, Roma, Lazio, Italy
| | - Nancy Mendelsohn
- Complex Health Solutions, United Healthcare, Minneapolis, Minnesota, USA
| | - Laura Merlini
- Department of Pediatric Radiology, Geneva University Hospitals Children's Hospital, Geneva, Switzerland
| | - Caitlin V Miller
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA
| | - Ansar Muhammad
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland,Depatment of Ophtalmology, University of Lausanne, Jules Gonin Eye Hospital, Lausanne, Switzerland,Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
| | - Sara Nuovo
- Department of Experimental Medicine, University of Rome La Sapienza, Rome, Lazio, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Lecco, Italy
| | - Wolfgang Schmidt
- Center for Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Sabrina Signorini
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Sabrina Siliquini
- Child Neuropsychiatry Unit, Paediatric Hospital G Salesi, Ancona, Italy
| | - Krzysztof Szczałuba
- Department of Medical Genetics, Warszawski Uniwersytet Medyczny, Warszawa, Poland
| | - Gessica Vasco
- Unit of Neurorehabilitation, Department of Neurosciences, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Meredith Wilson
- Department of Clinical Genetics, Children’s Hospital at Westmead, Sydney, New South Wales, Australia,Discipline of Genomic Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Ginevra Zanni
- Laboratory of Molecular Medicine, Unit of Muscular and Neurodegenerative Diseases, Department of Neuroscience, Bambino Gesu Children's Hospital, IRCCS, Rome, Italy
| | - Eugen Boltshauser
- Department of Pediatric Neurology (Emeritus), University Children's Hospital Zürich, Zurich, Zürich, Switzerland
| | - Dan Doherty
- Department of Pediatrics, University of Washington Center for Mendelian Genomics, WashingtonUSA,Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Enza Maria Valente
- Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy,Department of Molecular Medicine, University of Pavia, Pavia, Lombardia, Italy
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Gana S, Serpieri V, Valente EM. Genotype-phenotype correlates in Joubert syndrome: A review. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:72-88. [PMID: 35238134 PMCID: PMC9314610 DOI: 10.1002/ajmg.c.31963] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/04/2022] [Accepted: 02/15/2022] [Indexed: 01/20/2023]
Abstract
Joubert syndrome (JS) is a genetically heterogeneous primary ciliopathy characterized by a pathognomonic cerebellar and brainstem malformation, the “molar tooth sign,” and variable organ involvement. Over 40 causative genes have been identified to date, explaining up to 94% of cases. To date, gene‐phenotype correlates have been delineated only for a handful of genes, directly translating into improved counseling and clinical care. For instance, JS individuals harboring pathogenic variants in TMEM67 have a significantly higher risk of liver fibrosis, while pathogenic variants in NPHP1, RPGRIP1L, and TMEM237 are frequently associated to JS with renal involvement, requiring a closer monitoring of liver parameters, or renal functioning. On the other hand, individuals with causal variants in the CEP290 or AHI1 need a closer surveillance for retinal dystrophy and, in case of CEP290, also for chronic kidney disease. These examples highlight how an accurate description of the range of clinical symptoms associated with defects in each causative gene, including the rare ones, would better address prognosis and help guiding a personalized management. This review proposes to address this issue by assessing the available literature, to confirm known, as well as to propose rare gene‐phenotype correlates in JS.
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Affiliation(s)
- Simone Gana
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy
| | | | - Enza Maria Valente
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
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8
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Chen C, Gao J, Lv Q, Xu C, Xia Y, Du A. Retinitis pigmentosa and molar tooth sign caused by novel AHI1 compound heterozygote pathogenic variants. BMC Med Genomics 2021; 14:242. [PMID: 34627237 PMCID: PMC8502301 DOI: 10.1186/s12920-021-01089-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 09/23/2021] [Indexed: 11/30/2022] Open
Abstract
Background Joubert syndrome (JS) is a group of rare congenital disorders characterized by cerebellar vermis dysplasia, developmental delay, and retina dysfunctions. Herein, we reported a Chinese patient carrying a new variant in the AHI1 gene with mild JS, and the 3D structure of the affected Jouberin protein was also predicted. Case presentation The patient was a 31-year-old male, who presented difficulty at finding toys at the age of 2 years, night blindness from age of 5 years, intention tremor and walking imbalance from 29 years of age. Tubular visual field and retina pigmentation were observed on ophthalmology examinations, as well as molar tooth sign on brain magnetic resonance imaging (MRI). Whole exome sequence revealed two compound heterozygous variants at c.2105C>T (p.T702M) and c.1330A>T (p.I444F) in AHI1 gene. The latter one was a novel mutation. The 3D protein structure was predicted using I-TASSER and PyMOL, showing structural changes from functional β-sheet and α-helix to non-functional D-loop, respectively. Conclusions Mild JS due to novel variants at T702M and I444F in the AHI1 gene was reported. The 3D-structural changes in Jouberin protein might underlie the pathogenesis of JS.
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Affiliation(s)
- Chunyan Chen
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Jiong Gao
- WuXiDiagnostice, No. 31 Yiwei Road Waigaoqiao Pilot Free Trade Zone, Shanghai, 200131, China
| | - Qing Lv
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Chen Xu
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Yu Xia
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Ailian Du
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China.
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Karamzade A, Babaei M, Saberi M, Golchin N, Khalil Nejad Sani Banaei A, Eshaghkhani Y, Golchehre Z, Keramatipour M. Identification of a novel truncating variant in AHI1 gene and a brief review on mutations spectrum. Mol Biol Rep 2021; 48:5339-5345. [PMID: 34191236 DOI: 10.1007/s11033-021-06508-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
Joubert syndrome (JS) is a rare inherited neurodevelopmental condition characterized by hypotonia, ataxia, developmental delay, abnormal eye movements, neonatal respiratory disturbance and unique midbrain-hindbrain malformation, known as the molar tooth sign. JS is a genetically heterogeneous disorder with nearly 35 ciliary genes are implicated in its pathogenesis. AHI1 gene is one of the most frequently mutated gene in JS patients which is accounted for 8-11% of cases, particularly in Arab population. AHI1 encodes a cilium-localized protein with a significant role in mediating vesicle trafficking, ciliogenesis and cell polarity. Here, we report a novel pathogenic variant in AHI1 gene and review previously published mutations in AHI1 gene briefly. Whole exome sequencing was employed to determine the causative mutation in an Iranian Arab family with JS from southwestern Iran. Segregation analysis of the candidate variant in the family members was performed using PCR-Sanger sequencing. This approach found a novel homozygous nonsense variant c.832C > T (p.Gln278Ter) in AHI1. Segregation analysis was consistent with individual's phenotype and an autosomal recessive pattern in the family. The variant residing in a relatively highly conserved region and fulfilled the criteria required to be classified as a pathogenic variant based on American College of Medical Genetics and Genomics guidelines. This study confirms the diagnosis of JS in this family and highlights the efficiency of next-generation sequencing-based technique to identify the genetic causes of hereditary disorders with locus heterogeneity.
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Affiliation(s)
- Arezou Karamzade
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Watson Genetic Laboratory, North Kargar street, Tehran, Iran
| | - Meisam Babaei
- Department of Pediatrics, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Mohammad Saberi
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Neda Golchin
- Watson Genetic Laboratory, North Kargar street, Tehran, Iran
| | | | - Yeganeh Eshaghkhani
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Golchehre
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Keramatipour
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. .,Watson Genetic Laboratory, North Kargar street, Tehran, Iran.
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10
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Zhang C, Sun Z, Xu L, Che F, Liu S. Novel compound heterozygous CPLANE1 variants identified in a Chinese family with Joubert syndrome. Int J Dev Neurosci 2021; 81:529-538. [PMID: 34091942 DOI: 10.1002/jdn.10135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/24/2021] [Accepted: 05/30/2021] [Indexed: 11/08/2022] Open
Abstract
Joubert syndrome (JS) and JS-related disorders (JSRD) are a group of neurodevelopmental diseases that share the "molar tooth sign" on axial brain magnetic resonance imaging (MRI), accompanied by cerebellar vermis hypoplasia, ataxia, hypotonia, and developmental delay. To identify variants responsible for the clinical symptoms of a Chinese family with JS and to explore the genotype-phenotype associations, we conducted a series of clinical examinations, including blood tests, brain MRI scans, ultrasound imaging, and ophthalmologic examination. Genomic DNA was extracted from the peripheral blood of the six-person family, and the pathogenic variants were detected by whole-exome sequencing (WES) and verified by Sanger sequencing. WES revealed two novel compound heterozygous variants in CPLANE1: c.1270C>T (p.Arg424*) in exon 10 and c.8901C>A (p.Tyr2967*) in exon 48 of one child, inherited from each parent. Both variants were absent in ethnically matched Chinese control individuals and were either absent or present at very low frequencies in public databases, suggesting that these variants could be the pathogenic triggers of the JS phenotype. Notably, these CPLANE1 sequence variants were related to the pathogenesis of autosomal recessive JS in this study. The newly discovered variants expand the mutation spectrum of CPLANE1, which assists in understanding the molecular mechanism underlying JS and improving the recognition of genetic counseling, particularly for families with a history of autosomal recessive JS.
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Affiliation(s)
- Cheng Zhang
- Department of Neurology, The Eleventh Clinical Medical College of Qingdao University, Linyi People's Hospital, Linyi, China.,Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Zhenchao Sun
- Department of Neurology, The Eleventh Clinical Medical College of Qingdao University, Linyi People's Hospital, Linyi, China
| | - Lulu Xu
- Department of Geriatric Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Fengyuan Che
- Department of Neurology, The Eleventh Clinical Medical College of Qingdao University, Linyi People's Hospital, Linyi, China
| | - Shiguo Liu
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China
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11
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Non-classic splicing mutation in the CPLANE1 (C5orf42) gene cause Joubert syndrome in a fetus with severe craniocerebral dysplasia. Eur J Med Genet 2021; 64:104212. [PMID: 33794348 DOI: 10.1016/j.ejmg.2021.104212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/24/2021] [Accepted: 03/25/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUD Joubert syndrome is a rare neurodevelopmental disorder characterized by clinical and genetic heterogeneity. The characteristic molar tooth sign, which resulted from cerebellar vermis hypoplasia and midbrain anomalies, is expected to be the key diagnostic feature for this disease. However, it is not easy to make a definite diagnosis in prenatal only based on the imageology due to its clinical heterogeneity. CASE REPORT We report on a fetus who was detected cerebellum dysplasia and encephalocele by ultrasound at 19 and 23 gestational weeks and confirmed by MRI examination. The pregnancy was terminated at 23 weeks of gestation. Postaxial polydactyly and deficiency in occipital bone and skin were identified in the induced fetus. RESULTS The whole exome sequencing identified a novel compound heterozygous variation in the CPLANE1 gene related with Joubert syndrome, including a 2-bp insertion, NM_023073.3:c.1383_1384dup; p.(Gly462Glufs*3) and a non-classic splicing variation, NC_000005.10(NM_023073.3):c.7691-5_7691-4del. The pathogenicity of the non-classic splicing variation was further confirmed by cDNA level sequencing, which showed a exon 39 skipping that would introduce a premature termination. The novel compound heterozygous variation caused a complete function loss of the CPLANE1 gene. CONCLUSION The cerebellum dysplasia fetus without obvious molar tooth sign was finally diagnosed as Joubert syndrome, combined with genetic detecting and the postnatal clinical symptoms. We also highlight the clinical heterogeneity of encephalodysplasia in Joubert syndrome, which increases the clinical diagnosis difficulty, especially for prenatal diagnosis. Our findings provided a new perspective for the prenatal diagnosis of Joubert syndrome with severe craniocerebral dysplasia and expanded the variation spectrum of the CPLANE1 gene.
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12
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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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13
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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: 50] [Impact Index Per Article: 10.0] [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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14
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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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15
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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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