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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: 3] [Impact Index Per Article: 0.8] [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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Suzuki T, Miyake N, Tsurusaki Y, Okamoto N, Alkindy A, Inaba A, Sato M, Ito S, Muramatsu K, Kimura S, Ieda D, Saitoh S, Hiyane M, Suzumura H, Yagyu K, Shiraishi H, Nakajima M, Fueki N, Habata Y, Ueda Y, Komatsu Y, Yan K, Shimoda K, Shitara Y, Mizuno S, Ichinomiya K, Sameshima K, Tsuyusaki Y, Kurosawa K, Sakai Y, Haginoya K, Kobayashi Y, Yoshizawa C, Hisano M, Nakashima M, Saitsu H, Takeda S, Matsumoto N. Molecular genetic analysis of 30 families with Joubert syndrome. Clin Genet 2016; 90:526-535. [PMID: 27434533 DOI: 10.1111/cge.12836] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/27/2016] [Accepted: 07/14/2016] [Indexed: 02/02/2023]
Abstract
Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.
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Affiliation(s)
- T Suzuki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - N Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Y Tsurusaki
- Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - N Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan
| | - A Alkindy
- Department of Genetics, Sultan Qaboos University Hospital, Muscat, Oman
| | - A Inaba
- Yokohama City University Medical Center, Children's Medical Center, Yokohama, Japan
| | - M Sato
- Division of Nephrology and Rheumatology, National Center for Child Health and Development, Tokyo, Japan
| | - S Ito
- Department of Pediatrics, Graduate school of Medicine, Yokohama City University, Yokohama, Japan
| | - K Muramatsu
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan
| | - S Kimura
- Kumamoto City Child Development Support Center, Kumamoto, Japan
| | - D Ieda
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - S Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - M Hiyane
- Division of Child Neurology, Okinawa Prefectural Southern Medical Center & Children's Medical Center, Okinawa, Japan
| | - H Suzumura
- Department of Pediatrics, Dokkyo Medical University, Tochigi, Japan
| | - K Yagyu
- Department of Child and Adolescent Psychiatry, Graduate School of Medicine, Hokkaido University, Hokkaido, Japan
| | - H Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - M Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - N Fueki
- Division of Rehabilitation, Nagano Children's Hospital, Nagano, Japan
| | - Y Habata
- Department of Pediatric Rehabilitation, Hokkaido Medical Center for Child Health and Rehabilitation, Hokkaido, Japan
| | - Y Ueda
- Nire-no-kai Children's Clinic, Hokkaido, Japan
| | - Y Komatsu
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - K Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - K Shimoda
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Y Shitara
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - S Mizuno
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Aichi, Japan
| | - K Ichinomiya
- Department of Neonatology, Gunma Children's Medical Center, Gunma, Japan
| | - K Sameshima
- Division of Medical Genetics, Gunma Children's Medical Center, Gunma, Japan
| | - Y Tsuyusaki
- Division of Neurology, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - K Kurosawa
- Division of Medical Genetics, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Y Sakai
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - K Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital, Sendai, Japan
| | - Y Kobayashi
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan.,Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, UK
| | - C Yoshizawa
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan
| | - M Hisano
- Department of Nephrology, Chiba Children's Hospital, Chiba, Japan
| | - M Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - H Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - S Takeda
- Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - N Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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