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Yang M, Xie H, Xu B, Xiang Q, Wang H, Hu T, Liu S. Identification of a novel EXT2 frameshift mutation in a family with hereditary multiple exostoses by whole-exome sequencing. J Clin Lab Anal 2021; 35:e23968. [PMID: 34403521 PMCID: PMC8418499 DOI: 10.1002/jcla.23968] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 08/04/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hereditary multiple exostoses (HME), also referred to as multiple osteochondromas, is an autosomal dominant skeletal disease characterized by the development of multiple overgrown benign bony tumors capped by cartilage and is associated with bone deformity, joint limitation, and short stature. Mutations in exostosin glycosyltransferase (EXT)1 and EXT2 genes, which are located on chromosomes 8q24.1 and 11p13, contribute to the pathogenesis of HME. METHODS In the present study, a genetic analysis of a four-generation Chinese family with HME was conducted using whole-exome sequencing (WES), followed by validation using Sanger sequencing. RESULTS A novel heterozygous frameshift mutation in exon 5 of EXT2 (c.944dupT, p.Leu316fs) was identified in all affected individuals but was not detected in any unaffected individuals. This mutation results in a frameshift that introduces a premature termination codon at position 318 (p.Leu316fs) with the ability to produce a truncated EXT2 protein that lacks the last 433 amino acids at its C-terminal to indicate a defective exostosin domain and the absence of the glycosyltransferase family 64 domain, or to lead to the degradation of mRNAs by nonsense-mediated mRNA decay, which is critical for the function of EXT2. CONCLUSION Our results indicate that WES is effective in extending the EXT mutational spectra and is advantageous for genetic counseling and the subsequent prenatal diagnosis.
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Affiliation(s)
- Mei Yang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Hanbing Xie
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Bocheng Xu
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Qinqin Xiang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - He Wang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Ting Hu
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Shanling Liu
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
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Zhang L, Yu J, Xian Y, Wen X, Guan X, Guo Y, Luo M, Dou Y. Application of high-throughput sequencing for hereditary thrombocytopenia in southwestern China. J Clin Lab Anal 2021; 35:e23896. [PMID: 34237177 PMCID: PMC8373334 DOI: 10.1002/jcla.23896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 06/19/2021] [Accepted: 06/25/2021] [Indexed: 12/26/2022] Open
Abstract
Background The aim of this study was to design and analyze the applicability of a 21‐gene high‐throughput sequencing (HTS) panel in the molecular diagnosis of patients with hereditary thrombocytopenia (HT). Methods A custom target enrichment library was designed to capture 21 genes known to be associated with HTs. Twenty‐four patients with an HT phenotype were studied using this technology. Results One pathogenic variant on the MYH9 gene and one likely pathogenic variant on the ABCG8 gene previously known to cause HTs were identified. Additionally, 3 previously reported variants affecting WAS, ADAMTS13, and GP1BA were detected, and 9 novel variants affecting FLNA, ITGB3, NBEAL2, MYH9, VWF, and ANKRD26 genes were identified. The 12 variants were classified to be of uncertain significance. Conclusion Our results demonstrate that HTS is an accurate and reliable method of pre‐screening patients for variants in known HT‐causing genes. With the advantage of distinguishing HT from immune thrombocytopenia, HTS could play a key role in improving the clinical management of patients.
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Affiliation(s)
- Luying Zhang
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Jie Yu
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ying Xian
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xianhao Wen
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xianmin Guan
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yuxia Guo
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Mingzhu Luo
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ying Dou
- Department of Hematology and Oncology, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
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Wang F, Cai J, Wang J, He M, Mao J, Zhu K, Zhao M, Guan Z, Li L, Jin H, Shu Q. A novel WT1 gene mutation in a chinese girl with denys-drash syndrome. J Clin Lab Anal 2021; 35:e23769. [PMID: 33942367 PMCID: PMC8128316 DOI: 10.1002/jcla.23769] [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: 11/10/2020] [Revised: 03/03/2021] [Accepted: 03/13/2021] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE Denys-Drash syndrome (DDS) is defined by the triad of Wilms tumor, nephrotic syndrome, and/or ambiguous genitalia. Genetic testing may help identify new gene mutation sites and play an important role in clinical decision-making. METHODS We present a patient with an XY karyotype and female appearance, nephropathy, and Wilms tumor in the right kidney. Genomic DNA was extracted from peripheral blood cells according to standard protocols. "Next-generation" sequencing (NGS) was performed to identify novel variants. The variant was analyzed with Mutation Taster, and its function was explored by a cell growth inhibition assay. RESULTS We found the first case of Denys-Drash syndrome with the uncommon missense mutation (c.1420C>T, p.His474 Tyr) in the WT1 gene. In silico analysis, the variant was predicted "disease-causing" by Mutation Taster. The mutated variant showed a weaker effect in inhibiting tumor cells than wild-type WT1. CONCLUSIONS The uncommon missense mutation (c.1420C>T, p.His474 Tyr) in the WT1 gene may be a crucial marker in DDS.
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Affiliation(s)
- Faliang Wang
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiabin Cai
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Jinhu Wang
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Min He
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Junqing Mao
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Kun Zhu
- Department of Pathology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Manli Zhao
- Department of Pathology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhonghai Guan
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Linjie Li
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Hongchuan Jin
- Laboratory of Cancer Biology, Key Lab of Biotherapy in Zhejiang, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qiang Shu
- Department of Surgical Oncology, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
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Nasirshalal M, Panahi M, Javanshir N, Salmani H. Identification of a novel heterozygous mutation in the MITF gene in an Iranian family with Waardenburg syndrome type II using next-generation sequencing. J Clin Lab Anal 2021; 35:e23792. [PMID: 33942382 PMCID: PMC8183924 DOI: 10.1002/jcla.23792] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 12/30/2022] Open
Abstract
Background Waardenburg syndrome (WS) is a genetically heterogeneous syndrome with both autosomal recessive and dominant inheritance. WS causes skin and iris pigmentation accumulation and sensorineural hearing loss, in varying degrees. There are four WS types with different characteristics. WS1 and WS2 are the most common and have a dominant inheritance. WS2 is caused by mutations in the microphthalmia‐associated transcription factor (MITF) gene. Methods An Iranian couple with hearing loss was recruited in the present study. First, they were screened for GJB2 and GJB6 gene mutations, and then whole‐exome sequencing 100X was performed along with bioinformatics analysis. Results A novel pathogenic heterozygous mutation, c.425T>A; p.L142Ter, was detected in the MITF gene's exon 4. Bioinformatics analysis predicted c.425T>A; p.L142Ter as a possible pathogenic variation. It appears that the mutated transcript level declines through nonsense‐mediated decay. It probably created a significantly truncated protein and lost conserved and functional domains like basic helix‐loop‐helix‐zipper proteins. Besides, the variant was utterly co‐segregated with the disease within the family. Conclusions We investigated an Iranian family with congenital hearing loss and identified a novel pathogenic variant c.425T>A; p. L142Ter in the MITF gene related to WS2. This variant is a nonsense mutation, probably leading to a premature stop codon. Our data may be beneficial in upgrading gene mutation databases and identifying WS2 causes.
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Affiliation(s)
- Mahzad Nasirshalal
- Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Panahi
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nahid Javanshir
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tabriz, Iran
| | - Hamzeh Salmani
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Zhang T, Jia C, Dong Z, Li C, Lu W. A novel mutation in NF1 gene of patient with Neurofibromatosis type 1: A case report and functional study. Mol Genet Genomic Med 2021; 9:e1643. [PMID: 33764694 PMCID: PMC8172195 DOI: 10.1002/mgg3.1643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/17/2021] [Accepted: 02/10/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 is an autosomal dominant inherited disease and caused by NF1 gene mutation. Its clinical manifestations include multiple cafe´-au lait (CAL) spots, skinfold freckling, neurofibroma, bone dysplasia, learning disabilities, and an increased risk of malignancy. METHODS AND RESULTS Here, we reported a Chinese patient bearing with a novel NF1 mutation (c.2064delGGATGCAGCGG/p.Gly672AsnfsTer24) and complaining mainly about bone phenotype. Functional studies found that this novel mutation caused the damage of NF1 mRNA and protein levels, and lost the inhibition on Ras/Erk signaling. CONCLUSION A novel mutation in NF1 gene was identified and in vitro functional studies were performed, which provided a potential molecular mechanism to explain the bone maldevelopment of patients with neurofibromatosis type 1.
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Affiliation(s)
- Tingting Zhang
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
| | - Caiwei Jia
- Cancer CenterShanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghaiChina
| | - Zhiya Dong
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
| | - Chuanyin Li
- Cancer CenterShanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghaiChina
| | - Wenli Lu
- Department of PediatricsRuijin Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina
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Wang Z, Dong H, Ji X, Luan S, Cao H. Association of an insertion mutation in PRRT2 with hereditary spastic paraplegia accompanied by polyneuropathy. J Clin Lab Anal 2021; 35:e23772. [PMID: 33826176 PMCID: PMC8183916 DOI: 10.1002/jcla.23772] [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: 12/24/2020] [Revised: 03/02/2021] [Accepted: 03/13/2021] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Hereditary spastic paraplegia is a rare familial hereditary neurodegenerative disease caused by multiple autosomal dominant mutations. More than 50 mutant genes have been reported to be associated with this disease. METHODS In this study, we have reported a rare insertion mutation site in PRRT2 that caused a familial disorder of hereditary spastic paraplegia accompanied by polyneuropathy. RESULTS We used second-generation sequencing of samples of the proband's familial genome and found an insertion mutation of C/CC in NM_001256443:c.641dupC that was localized to the second exon of PRRT2. This functional mutation can cause an amino acid sequence change (arginine >proline) and dysfunctional neuronal transmembrane proteins, which might have been related to the onset of hereditary spastic paraplegia accompanied by polyneuropathy in the family reported in this study. CONCLUSION The discovery of this mutation site provides an important theoretical basis for specific gene-based diagnosis and treatment of hereditary spastic paraplegia.
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Affiliation(s)
- Zhaoyu Wang
- Department of Neurology, First Affiliated Hospital of Dalian Medical University, Dalian, China.,Department of Neurology, The Central Hospital of Wuhan, Wuhan, China
| | - Huijie Dong
- Department of Cardiology, Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xiaofei Ji
- Department of Neurology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Siyu Luan
- Department of Neurology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Hua Cao
- Department of Neurology, First Affiliated Hospital of Dalian Medical University, Dalian, China
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Zhou T, Yang X, Chen Z, Zhou Y, Cao X, Zhao C, Zhao J. A novel COL2A1 mutation causing spondyloepiphyseal dysplasia congenita in a Chinese family. J Clin Lab Anal 2021; 35:e23728. [PMID: 33590889 PMCID: PMC8059726 DOI: 10.1002/jcla.23728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/18/2021] [Accepted: 01/28/2021] [Indexed: 11/11/2022] Open
Abstract
Background Spondyloepiphyseal dysplasia congenita is an autosomal dominant cartilaginous dysplasia characterized by short trunk, abnormal epiphysis, and flattened vertebral body. Skeletal features of SEDC are present at birth and evolve over time. Other features of SEDC include myopia and/or retinal degeneration with retinal detachment and cleft palate. A mutation in the COL2A1 gene located in 12q13.11 is considered as one of the important causes of SEDC. In 2016, Barat‐Houari et al. reported a large number of COL2A1 mutations. Among them, a non‐synonymous mutation in COL2A1 exon 37, c.2437G>A (p. Gly813Arg), has been reported to cause SEDC in only one patient from France so far. Methods We followed up a patient with SEDC phenotype and his family members. The clinical manifestations, physical examination and imaging examination, including X‐ray, CT and MRI, were recorded. The whole‐exome sequencing was used to detect the patients' genes, and the pathogenic genes were screened out by comparing with many databases. Results We report a Chinese patient with SEDC phenotype characterized by short trunk, abnormal epiphysis, flattened vertebral body, narrow intervertebral space, dysplasia of the odontoid process, chicken chest, scoliosis, hip and knee dysplasia, and joint hypertrophy. Gene sequencing analysis showed that the patient had a heterozygous mutation (c.2437G>A; p. Gly813Arg) in the COL2A1 gene. No COL2A1 mutation or SEDC phenotype was observed in his family members. This is the first report of SEDC caused by this mutation in an East Asian family. Conclusion This report provides typical clinical, imaging, and genetic evidence for SEDC, confirming that a de novo mutation in the COL2A1 gene, c.2437G>A (p. Gly813Arg), causes SEDC in Chinese population.
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Affiliation(s)
- Tangjun Zhou
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao Yang
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhiqian Chen
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yifan Zhou
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiankun Cao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Changqing Zhao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jie Zhao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Bitarafan F, Seyedena SY, Mahmoudi M, Garshasbi M. Identification of novel variants in Iranian consanguineous pedigrees with nonsyndromic hearing loss by next-generation sequencing. J Clin Lab Anal 2020; 34:e23544. [PMID: 32864763 PMCID: PMC7755797 DOI: 10.1002/jcla.23544] [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: 04/12/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 12/17/2022] Open
Abstract
Background The extremely high genetic heterogeneity of hearing loss due to diverse group of genes encoding proteins required for development, function, and maintenance of the complex auditory system makes the genetic diagnosis of this disease challenging. Up to now, 121 different genes have been identified for nonsyndromic hearing loss (NSHL), of which 76 genes are responsible for the most common forms of NSHL, autosomal recessive nonsyndromic hearing loss (ARNSHL). Methods After excluding mutations in the most common ARNSHL gene, GJB2, by Sanger sequencing, genetic screening for a panel of genes responsible for hereditary hearing impairment performed in 9 individuals with ARNSHL from unrelated Iranian consanguineous pedigrees. Results One compound heterozygote and eight homozygote variants, of which five are novel, were identified: CDH23:p.(Glu1970Lys), and p.(Ala1072Asp), GIPC3:p.(Asn82Ser), and (p.Thr41Lys), MYO7A:p.[Phe456Phe]; p.[Met708Val], and p.(Gly163Arg), TECTA:p.(Leu17Leufs*19), OTOF:c.1392+1G>A, and TRIOBP:p.(Arg1068*). Sanger sequencing confirmed the segregation of the variants with the disease in each family. Conclusion Finding more variants and expanding the spectrum of hearing impairment mutations can increase the diagnostic value of molecular testing in the screening of patients and can improve counseling to minimize the risk of having affected children for at risk couples.
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Affiliation(s)
- Fatemeh Bitarafan
- Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Seyed Yousef Seyedena
- Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Mahdi Mahmoudi
- Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran
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Wang F, Guo S, Li P. Two novel mutations in the MCM8 gene shared by two Chinese siblings with primary ovarian insufficiency and short stature. Mol Genet Genomic Med 2020; 8:e1396. [PMID: 32652893 PMCID: PMC7507566 DOI: 10.1002/mgg3.1396] [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: 03/04/2020] [Revised: 06/02/2020] [Accepted: 06/08/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Minichromosome maintenance complex component 8 (MCM8) is responsible for homologous recombination and DNA double-strand breaks (DSBs) repair and is the cause of primary ovarian insufficiency (POI), which is seldom diagnosed in adolescents and children. METHODS Whole-exome sequencing was performed in a 13-year-old girl, and Sanger sequencing was used to identify potentially pathogenic variants in her sister (aged 6 years and 7 months) and parents. To identify potential pathogenic mutations, DSBs were induced by mitomycin C (MMC), and the DNA repair capacity was evaluated by the histone H2AX phosphorylation level. RESULTS Two novel mutations of MCM8, i.e., c.724T>C (p.C242R) and c.1334C>A (p.S445*), were identified in a 13-year-old girl with POI who exhibited disappeared bilateral ovaries and short stature (height standard difference score [HtSDS] = -3.05), and her sister (aged 6 years and 7 months) with progressive POI whose ovary size decreased from normal to unclear and height growth gradually slowed. In the functional experiments, compared with the wild-type, HeLa cells overexpressing mutant p.C242R and p.S445* showed a higher sensitivity to MMC. Furthermore, the mutant p.S445* has a more deleterious effect on DNA damage repair. CONCLUSION Our results reveal that affected children with the novel pathogenetic mutations p.C242R and p.S445* in the MCM8 gene are characterized by POI, short stature, cancer susceptibility, and genomic instability.
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Affiliation(s)
- Fei Wang
- Department of Endocrinology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Sheng Guo
- Department of Endocrinology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Pin Li
- Department of Endocrinology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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Min J, Mao B, Wang Y, He X, Gao S, Wang H. A Heterozygous Novel Mutation in TFAP2A Gene Causes Atypical Branchio-Oculo-Facial Syndrome With Isolated Coloboma of Choroid: A Case Report. Front Pediatr 2020; 8:380. [PMID: 32766183 PMCID: PMC7379893 DOI: 10.3389/fped.2020.00380] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 06/04/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Branchio-oculo-facial syndrome (BOFS) is a rare congenital developmental disorder with highly variable clinical phenotypes in autosomal dominant inheritance. The aim of this study is to identify disease-causing mutations in a Chinese family with predominant coloboma of choroid. Case report: We described a family (a mother and her daughter) with unclear clinical diagnosis. The mother (proband) presented with bilateral coloboma of choroid, whereas her daughter had a relatively severe phenotype and presented with larger bilateral choroid coloboma and high-vaulted arch. We applied the next generation sequencing (NGS) panel and analyzed 776 genes related to inherited ocular disorders on the proband. Four candidate heterozygous variants in four genes, respectively, were detected in the proband. Validation of these variants were subsequently performed in the family using Sanger sequencing. Among these variants, a novel nonsense mutation c.912C>A, p.(Cys304*) (NM_001042425.2) which in exon 6 of the conserved helix-span-helix domain in TFAP2A results in a premature termination codon. It may trigger nonsense-mediated mRNA decay (NMD). Both the affected mother and daughter had this variant, whereas it was absent in the asymptomatic father. Together with the silicon tools and clinical features, we concluded that the variant c.912C>A, p.(Cys304*), was the second reported nonsense mutation in TFAP2A gene, which was the disease-causing mutation of the family. Conclusion: There are many hereditary diseases accompanied by ocular anomalies. For instance, BOFS, patients with atypical features are always at risk of being under-diagnosed. NGS is a powerful method to identify the genetic cause and improve genetic counseling for less clarified hereditary ocular diseases.
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Affiliation(s)
- Jie Min
- Department of Obstetrics and Gynecology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bing Mao
- Department of Neurology, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yong Wang
- Wuhan Aier Eye Hospital, Aier School of Ophthalmology, Central South University, Wuhan, China
| | - Xuelian He
- Department of Obstetrics and Gynecology, Wuhan Medical and Health Center for Women and Children, Wuhan, China
| | | | - Hairong Wang
- BGI-Wuhan Clinical Laboratories, BGI-Shenzhen, Wuhan, China
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Zhang R, Chen S, Han P, Chen F, Kuang S, Meng Z, Liu J, Sun R, Wang Z, He X, Li Y, Guan Y, Yue Z, Li C, Kumar Dey S, Zhu Y, Banerjee S. Whole exome sequencing identified a homozygous novel variant in CEP290 gene causes Meckel syndrome. J Cell Mol Med 2019; 24:1906-1916. [PMID: 31840411 PMCID: PMC6991682 DOI: 10.1111/jcmm.14887] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/01/2022] Open
Abstract
Meckel syndrome (MKS) is a pre‐ or perinatal multisystemic ciliopathic lethal disorder with an autosomal recessive mode of inheritance. Meckel syndrome is usually manifested with meningo‐occipital encephalocele, polycystic kidney dysplasia, postaxial polydactyly and hepatobiliary ductal plate malformation. Germline variants in CEP290 cause MKS4. In this study, we investigated a 35‐years‐old Chinese female who was 17+1 weeks pregnant. She had a history of adverse pregnancy of having foetus with multiple malformations. We performed ultrasonography and identified the foetus with occipital meningoencephalocele and enlarged cystic dysplastic kidneys. So, she decided to terminate her pregnancy and further genetic molecular analysis was performed. We identified the aborted foetus without postaxial polydactyly. Histological examination of foetal kidney showed cysts in kidney and thinning of the renal cortex with glomerular atrophy. Whole exome sequencing identified a novel homozygous variant (c.2144T>G; p.L715*) in exon 21 of the CEP290 in the foetus. Sanger sequencing confirmed that both the parents of the foetus were carrying this variant in a heterozygous state. This variant was not identified in two elder sisters of the foetus as well as in the 100 healthy individuals. Western blot analysis showed that this variant leads to the formation of truncated CEP290 protein with the molecular weight of 84 KD compared with the wild‐type CEP290 protein of 290 KD. Hence, it is a loss‐of‐function variant. We also found that the mutant cilium appears longer in length than the wild‐type cilium. Our present study reported the first variant of CEP290 associated with MKS4 in Chinese population.
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Affiliation(s)
- Rui Zhang
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Shaoyun Chen
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Peng Han
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Fangfang Chen
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Shan Kuang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Zhuo Meng
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Junnian Liu
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
| | - Ruliang Sun
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Zhiwei Wang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Xiaohong He
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Yong Li
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yuanning Guan
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | | | - Chen Li
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Hangzhou, China
| | - Subrata Kumar Dey
- Department of Biotechnology, Centre for Genetic Studies, School of Biotechnology and Biological Sciences, Maulana Abul Kalam Azad University of Technology (Formerly West Bengal University of Technology), Kolkata, India.,Brainware University, Barasat, India
| | - Yuanfang Zhu
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Santasree Banerjee
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China.,Brainware University, Barasat, India
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