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Zhang L, Wan Y, Wang N. Waardenburg syndrome type 4 coexisting with open-angle glaucoma: a case report. J Med Case Rep 2022; 16:264. [PMID: 35790984 PMCID: PMC9258067 DOI: 10.1186/s13256-022-03460-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/16/2022] [Indexed: 11/25/2022] Open
Abstract
Background Waardenburg syndrome is an autosomal dominant disorder with varying degrees of sensorineural hearing loss as well as abnormal pigmentation in hair, skin, and iris. There are four types of Waardenburg syndrome (1–4) with different characteristics. Mutations in six genes have been identified to be associated with the various types. Herein, we describe a case of Waardenburg syndrome type 4 combined with open-angle glaucoma. Case presentation A 43-year-old Han Chinese man had undergone trabeculectomy due to progression of visual field impairment and unstable intraocular pressure in both eyes. Slit-lamp examination revealed diffuse iris hypopigmentation in the left eye and hypopigmentation of part of the iris in the right eye. Fundus examination showed red, sunset-like fundus due to a lack of pigmentation in the retinal pigment epithelium layer, diffuse loss of the nerve fiber layer, and an excavated optic nerve head with advanced-stage glaucoma. Imaging was performed using anterior segment optical coherence tomography to detect the iris configuration. In the heterochromic iris portion, the normal part of the iris showed a clear hyperreflective signal of the anterior border layer, while atrophy of the pigmented anterior border layer showed a hyporeflective area of the anterior surface resulting in reduced light absorption. Two mutations of the endothelin receptor type B gene were recognized in this study. The first (c.1111G>A on exon 7) leads to an amino acid change from glycine to serine at codon 371. Sanger verification revealed that this mutation is inherited from the mother. The other mutation (c.553G>A) leads to an amino acid change from valine to methionine at codon 185. Sanger verification showed that this mutation was inherited from the father. Conclusion Waardenburg syndrome shows a remarkable diversity in clinical presentation and morphology. This disease can also present with open-angle glaucoma. Sequencing analysis revealed two heterozygous mutations in the EDNRB gene in this patient, inherited from his mother and father, respectively. These two sites constitute a compound heterozygous variation.
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Affiliation(s)
- Li Zhang
- Beijing Institute of Ophthalmology, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Line, Chongnei Street, Dongcheng District, Beijing, 100005, China.
| | - Yue Wan
- Beijing Institute of Ophthalmology, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Line, Chongnei Street, Dongcheng District, Beijing, 100005, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Line, Chongnei Street, Dongcheng District, Beijing, 100005, China
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Zardadi S, Rayat S, Hassani Doabsari M, Keramatipour M, Morovvati S. Waardenburg syndrome type 2A in a large Iranian family with a novel MITF gene mutation. BMC Med Genomics 2021; 14:230. [PMID: 34544414 PMCID: PMC8451132 DOI: 10.1186/s12920-021-01074-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/02/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The characteristics of Waardenburg syndrome (WS) as a scarce heritable disorder are sensorineural hearing loss and deficits of pigmentation in the skin, hair, and eye. Here, clinical features and detection of the mutation in the MITF gene of WS2 patients are reported in a sizable Iranian family. METHODS A man aged 28-years represented with symptoms of mild unilateral hearing loss (right ear), complete heterochromia iridis, premature graying prior to 30 years of age, and synophrys. In this research, there was a sizable family in Iran comprising three generations with seven WS patients and two healthy members. Whole exome sequencing was applied for proband for the identification of the candidate genetic mutations associated with the disease. The detected mutation in proband and investigated family members was validated by PCR-Sanger sequencing. RESULTS A novel heterozygous mutation, NM_198159.3:c.1026dup p.(Asn343Glufs*27), in exon 9 of the MITF gene co-segregated with WS2 in the affected family members. The variant was forecasted as a disease-causing variant by the Mutation Taster. According to the UniProt database, this variant has been located in basic helix-loop-helix (bHLH) domain of the protein with critical role in DNA binding. CONCLUSIONS A frameshift was caused by a nucleotide insertion, c.1026dup, in exon 9 of the MITF gene. This mutation is able to induce an early termination, resulting in forming a truncated protein capable of affecting the normal function of the MITF protein. Helpful information is provided through an exactly described mutations involved in WS to clarify the molecular cause of clinical characteristics of WS and have a contribution to better genetic counseling of WS patients.
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Affiliation(s)
- Safoura Zardadi
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Sima Rayat
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | | | - Mohammad Keramatipour
- Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeid Morovvati
- Department of Genetics, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
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Li Y, Xu Y, Li G, Chen K, Yu H, Gao J, Tian W, Liu Y, Liu P, Zhang L, Zhang Z. A Novel Frameshift Variant of the MITF Gene in a Chinese Family with Waardenburg Syndrome Type 2. Mol Syndromol 2021; 12:244-249. [PMID: 34421503 DOI: 10.1159/000513607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 12/06/2020] [Indexed: 11/19/2022] Open
Abstract
Waardenburg syndrome (WS) is a rare genetic disorder characterized by varying combinations of sensorineural hearing loss and abnormal pigmentation involving the hair, skin and iris. WS is classified into 4 subtypes (WS1-WS4) based on additional symptoms. WS2 is characterized by the absence of additional symptoms and is mainly attributed to variants in the microphthalmia-associated transcription factor (MITF) gene. We detected a novel frameshift variant c.1025_1032delGGAACAAG (NM_198159) of MITF in 5 patients with WS2 from the same Chinese family by using targeted next-generation sequencing and Sanger sequencing. Phenotypic and genotypic analyses of the family members suggested that this novel variants was pathogenic. Our finding expands the spectrum of MITF variants.
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Affiliation(s)
- Ying Li
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Yajuan Xu
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Genxia Li
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Kang Chen
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA.,Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.,Mucosal Immunology Studies Team, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Haiyang Yu
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Jinshuang Gao
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Weifang Tian
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Yuehua Liu
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Pingping Liu
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Linlin Zhang
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
| | - Zhan Zhang
- Molecular Genetics Laboratory, Department of Clinical Laboratory Science, The Third Affiliated Hospital of Zhengzhou University - Maternal and Child Health Hospital of Henan Province, Zhengzhou, China
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4
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Albarry MA, Latif M, Alreheli AQ, Awadh MA, Almatrafi AM, Albalawi AM, Basit S. Frameshift variant in MITF gene in a large family with Waardenburg syndrome type II and a co-segregation of a C2orf74 variant. PLoS One 2021; 16:e0246607. [PMID: 33571247 PMCID: PMC7877624 DOI: 10.1371/journal.pone.0246607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/21/2021] [Indexed: 11/30/2022] Open
Abstract
Waardenburg syndrome (WS) is a hereditary disorder affecting the auditory system and pigmentation of hair, eyes, and skin. Different variants of the disease exist with the involvement of mutation in six genes. The aim of the study is to identify the genetic defects underlying Waardenburg syndrome in a large family with multiple affected individuals. Here, in this study, we recruited a large family with eleven affected individuals segregating WS type 2. We performed whole genome SNP genotyping, whole exome sequencing and segregation analysis using Sanger approach. Whole genome SNP genotyping, whole exome sequencing followed by Sanger validation of variants of interest identified a novel single nucleotide deletion mutation (c.965delA) in the MITF gene. Moreover, a rare heterozygous, missense damaging variant (c.101T>G; p.Val34Gly) in the C2orf74 has also been identified. The C2orf74 is an uncharacterized gene present in the linked region detected by DominantMapper. Variants in MITF and C2orf74 follows autosomal dominant segregation with the phenotype, however, the variant in C2orf74 is incompletely penetrant. We proposed a digenic inheritance of variants as an underlying cause of WS2 in this family.
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Affiliation(s)
- Maan Abdullah Albarry
- Department of Ophthalmology, College of Medicine, Taibah University, Almadinah, Saudi Arabia
| | - Muhammad Latif
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah, Saudi Arabia
| | - Ahdab Qasem Alreheli
- Department of Ophthalmology, College of Medicine, Taibah University, Almadinah, Saudi Arabia
| | - Mohammed A. Awadh
- College of Applied Medical Sciences, Taibah University, Almadinah, Saudi Arabia
| | - Ahmad M. Almatrafi
- Department of Biology, College of Science, Taibah University, Almadinah, Saudi Arabia
| | - Alia M. Albalawi
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah, Saudi Arabia
- Department of Biology, College of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah, Saudi Arabia
- * E-mail:
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Zardadi S, Rayat S, Doabsari MH, Alishiri A, Keramatipour M, Shahri ZJ, Morovvati S. Four mutations in MITF, SOX10 and PAX3 genes were identified as genetic causes of waardenburg syndrome in four unrelated Iranian patients: case report. BMC Pediatr 2021; 21:70. [PMID: 33557787 PMCID: PMC7869501 DOI: 10.1186/s12887-021-02521-6] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/24/2021] [Indexed: 12/30/2022] Open
Abstract
Background Waardenburg syndrome (WS) is a rare genetic disorder. The purpose of this study was to investigate clinical and molecular characteristics of WS in four probands from four different Iranian families. Case presentation The first patient was a 1-year-old symptomatic boy with congenital hearing loss and heterochromia iridis with a blue segment in his left iris. The second case was a 1.5-year-old symptomatic girl who manifested congenital profound hearing loss, brilliant blue eyes, and skin hypopigmentation on the abdominal region at birth time. The third patient was an 8-month-old symptomatic boy with developmental delay, mild atrophy, hypotonia, brilliant blue eyes, skin hypopigmentation on her hand and foot, Hirschsprung disease, and congenital profound hearing loss; the fourth patient was a 4-year-old symptomatic boy who showed dystopia canthorum, broad nasal root, synophrys, skin hypopigmentation on her hand and abdomen, brilliant blue eyes, and congenital profound hearing loss. Whole exome sequencing (WES) was used for each proband to identify the underlying genetic factor. Sanger sequencing was performed for validation of the identified mutations in probands and the available family members. A novel heterozygous frameshift mutation, c.996delT (p.K334Sfs*15), on exon 8 of the MITF gene was identified in the patient of the first family diagnosed with WS2A. Two novel de novo heterozygous mutations including a missense mutation, c.950G > A (p.R317K), on exon 8 of the MITF gene, and a frameshift mutation, c.684delC (p.E229Sfs*57), on the exon 3 of the SOX10 gene were detected in patients of the second and third families with WS2A and PCWH (Peripheral demyelinating neuropathy, Central dysmyelinating leukodystrophy, Waardenburg syndrome, Hirschsprung disease), respectively. A previously reported heterozygous frameshift mutation, c.1024_1040del AGCACGATTCCTTCCAA, (p.S342Pfs*62), on exon 7 of the PAX3 gene was identified in the patient of the fourth family with WS1. Conclusions An exact description of the mutations responsible for WS provides useful information to explain the molecular cause of clinical features of WS and contributes to better genetic counseling of WS patients and their families.
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Affiliation(s)
- Safoura Zardadi
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Sima Rayat
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | | | - Aliagha Alishiri
- Faculty of Medicine, Hormozgan University of Medical Sciences, Hormozgan, Iran
| | - Mohammad Keramatipour
- Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zeynab Javanfekr Shahri
- School of Advanced Sciences and Technology, Islamic Azad University-Tehran Medical Sciences, Tehran, Iran
| | - Saeid Morovvati
- Department of Genetics, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
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6
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Yang S, Wang C, Zhou C, Kang D, Zhang X, Yuan H. A follow-up study of a Chinese family with Waardenburg syndrome type II caused by a truncating mutation of MITF gene. Mol Genet Genomic Med 2020; 8:e1520. [PMID: 33045145 PMCID: PMC7767564 DOI: 10.1002/mgg3.1520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/02/2020] [Accepted: 09/17/2020] [Indexed: 11/29/2022] Open
Abstract
Background Waardenburg syndrome (WS) is a highly clinically and genetically heterogeneous disease. The core disease phenotypes of WS are sensorineuronal hearing loss and pigmentary disturbance, which are usually caused by the absence of neural crest cell‐derived melanocytes. At present, four subtypes of WS have been defined, which are caused by seven genes. Waardenburg syndrome type 2 (WS2) is one of the most common forms. Two genes, MITF and SOX10, have been found to be responsible for majority of WS2. Methods In this study, we performed a clinical longitudinal follow‐up and mutation screening for a Chinese family with Waardenburg syndrome type II. Results A diversity of clinical manifestations was observed in this WS2 family. In addition to the congenital hearing loss of most affected family members, progressive hearing loss was also found in some WS2 patients. A nonsense mutation of c.328C>T (p.R110X) in MITF was identified in all affected family members. This mutation results in a truncated MITF protein, which is considered to be a disease‐causing mutation. Conclusion These findings offer a better understanding of the spectrum of MITF mutations and highlight the necessity of continuous hearing assessment in WS patients.
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Affiliation(s)
- Shuzhi Yang
- Department of Otolaryngology, The 4th Medical CenterChinese PLA General HospitalBeijingChina
- Department of Otorhinolaryngology Head and Neck SurgeryChinese PLA General HospitalBeijingChina
- National Clinical Research Center for Otorhinolaryngologic DiseaseChinese PLA General HospitalBeijingChina
| | - Cuicui Wang
- Center for Medical GeneticsSouthwest HospitalArmy Medical UniversityChongqingChina
| | - Chengyong Zhou
- Department of Otolaryngology, The 4th Medical CenterChinese PLA General HospitalBeijingChina
- Department of Otorhinolaryngology Head and Neck SurgeryChinese PLA General HospitalBeijingChina
- National Clinical Research Center for Otorhinolaryngologic DiseaseChinese PLA General HospitalBeijingChina
| | - DongYang Kang
- Institute Of OtolaryngologyChinese PLA General HospitalBeijingChina
| | - Xin Zhang
- Institute Of OtolaryngologyChinese PLA General HospitalBeijingChina
| | - Huijun Yuan
- Center for Medical GeneticsSouthwest HospitalArmy Medical UniversityChongqingChina
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7
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Liu Q, Cheng J, Lu Y, Zhou J, Wang L, Yang C, Yang G, Yang H, Cao J, Zhang Z, Sun Y. The clinical and genetic research of Waardenburg syndrome type I and II in Chinese families. Int J Pediatr Otorhinolaryngol 2020; 130:109806. [PMID: 31812001 DOI: 10.1016/j.ijporl.2019.109806] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/31/2019] [Accepted: 11/26/2019] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Waardenburg Syndrome (WS) is a neurocristopathy with an autosomal dominant mode of inheritance and highly genetic heterogeneity. To date, mutations of PAX3, SOX10, MITF, EDNRB, EDN3 and SNAI2 have been implicated in the pathogenesis of WS. In this study, we aimed to identify pathogenic genes among WS families and to analyze the pathogenic relationship between genotypes and phenotypes. METHODS In this study, all six families studied were from Hubei province, China.WS patients underwent screening for all deafness genes including PAX3, SOX10, MITF, EDNRB, EDN3 and SNAI2 using Massively Parallel Sequencing (MPS) and validation of mutations using Sanger sequencing. RESULTS Clinical evaluation revealed prominent phenotypic variability in Hubei WS patients. Two WS1 families and four WS2 families were diagnosed in six families. Sensorineural hearing loss was the most common, followed by iris pigmentary abnormality. Molecular genetic analysis of the WS genes for six families revealed five novel heterozygous mutations. Two mutations occurred in the PAX3 gene: one nonsense mutation c.667C > T(p.Arg223Ter) and one missense mutation c.220C > T(p.Arg74Cys).One missense mutation c.331T > C (p.Phe111Leu) and one nonsense mutation c.346C > T(p.Gln116Ter) were detected in the SOX10 gene. Two mutations were detected in the MITF gene: one splice site mutation c.859-1G > A and one nonsense mutation c.859G > T(p.Glu287Ter). Among them, the mutations (SOX10 c.331T > C and MITF c.859G > T) were de novo mutations. CONCLUSION In this study, six mutations were found to be associated with the phenotype of patients. Our data helped illuminate the phenotypic and genotypic spectrum of WS in Hubei province and could have implications for the genetic counseling of WS in Hubei province.
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Affiliation(s)
- Qin Liu
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Jing Cheng
- Medical Genetics Center, The First Affiliated Hospital, Army Medical University, Chongqing, 400038, China
| | - Yu Lu
- Medical Genetics Center, The First Affiliated Hospital, Army Medical University, Chongqing, 400038, China
| | - Jia Zhou
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Li Wang
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Changliang Yang
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Guang Yang
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Hui Yang
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Jingyuan Cao
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Zhao Zhang
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China
| | - Yi Sun
- Department of Otorhinolaryngology, General Hospital of Central Theater Command, Chinese People's Liberation Army, Wuhan, 430000, China; Southern Medical University, Guangzhou, 510000, China.
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8
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Albarry MA, Alreheli AQ, Albalawi AM, Basit S. Whole genome genotyping mapped regions on chromosome 2 and 18 in a family segregating Waardenburg syndrome type II. Saudi J Ophthalmol 2020; 33:326-331. [PMID: 31920441 PMCID: PMC6950962 DOI: 10.1016/j.sjopt.2019.09.004] [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: 01/01/2019] [Revised: 04/01/2019] [Accepted: 09/10/2019] [Indexed: 11/17/2022] Open
Abstract
Objectives Waardenburg syndrome is a rare genetic disorder. It is characterized by sensorineural hearing impairment and pigment defects of the skin, hair and iris. In some cases abnormalities in the tissues derived from neural crest have also been reported. Mutations in several genes have been reported as an underlying cause of Waardenburg syndrome. Objective of this study is to identify the chromosomal region(s) associated with Waardenburg syndrome in an extended Saudi family. Methods Genomic DNA was extracted from fifteen individuals of a Saudi family segregating Waardenburg syndrome. Whole genome SNP genotyping was performed to identify common identity by descent chromosomal region(s) shared by affected individuals. Results Pedigree analysis confirm autosomal dominant inheritance of Waardenburg syndrome type II in a family. Whole genome SNP genotypes were analyzed using AutoSNPa and DominantMapper tools. Shared identity by descent chromosomal regions were identified on chromosome 2 and chromosome 18. Regions were checked for known Waardenburg syndrome genes. No known gene is present in both regions. Conclusions In summary, we identified novel chromosomal regions associated with Waardenburg syndrome type II in a Saudi family. Deep sequencing of a complete candidate regions are required to identify the gene underlying Waardenburg syndrome in this family.
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Affiliation(s)
- Maan Abdullah Albarry
- Department of Ophthalmology, College of Medicine, Taibah University Almadinah, Saudi Arabia
| | - Ahdab Qasem Alreheli
- Department of Ophthalmology, College of Medicine, Taibah University Almadinah, Saudi Arabia
| | - Alia M Albalawi
- Center for Genetics and Inherited Diseases, Taibah University Almadinah, Saudi Arabia
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University Almadinah, Saudi Arabia
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DiStefano MT, Hemphill SE, Cushman BJ, Bowser MJ, Hynes E, Grant AR, Siegert RK, Oza AM, Gonzalez MA, Amr SS, Rehm HL, Abou Tayoun AN. Curating Clinically Relevant Transcripts for the Interpretation of Sequence Variants. J Mol Diagn 2018; 20:789-801. [PMID: 30096381 DOI: 10.1016/j.jmoldx.2018.06.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/20/2018] [Accepted: 06/19/2018] [Indexed: 10/28/2022] Open
Abstract
Variant interpretation depends on accurate annotations using biologically relevant transcripts. We have developed a systematic strategy for designating primary transcripts and have applied it to 109 hearing loss-associated genes that were divided into three categories. Category 1 genes (n = 38) had a single transcript; category 2 genes (n = 33) had multiple transcripts, but a single transcript was sufficient to represent all exons; and category 3 genes (n = 38) had multiple transcripts with unique exons. Transcripts were curated with respect to gene expression reported in the literature and the Genotype-Tissue Expression Project. In addition, high-frequency loss-of-function variants in the Genome Aggregation Database and disease-causing variants in ClinVar and the Human Gene Mutation Database across the 109 genes were queried. These data were used to classify exons as clinically significant, insignificant, or of uncertain significance. Interestingly, 6% of all exons, containing 124 reportedly disease-causing variants, were of uncertain significance. Finally, we used exon-level next-generation sequencing quality metrics generated at two clinical laboratories and identified a total of 43 technically challenging exons in 20 different genes that had inadequate coverage and/or homology issues that might lead to false-variant calls. We have demonstrated that transcript analysis plays a critical role in accurate clinical variant interpretation.
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Affiliation(s)
- Marina T DiStefano
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Sarah E Hemphill
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Brandon J Cushman
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Mark J Bowser
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Elizabeth Hynes
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Andrew R Grant
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Rebecca K Siegert
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Andrea M Oza
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Michael A Gonzalez
- Division of Genomic Diagnostics, The Children's Hospital of Philadelphia, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Sami S Amr
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts; Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Heidi L Rehm
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts; Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medical and Population Genetics, The Broad Institute of the Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Ahmad N Abou Tayoun
- Division of Genomic Diagnostics, The Children's Hospital of Philadelphia, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Genetics Department, Al Jalila Children's Specialty Hospital, Dubai, United Arab Emirates.
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10
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Mittal R, Patel AP, Nguyen D, Pan DR, Jhaveri VM, Rudman JR, Dharmaraja A, Yan D, Feng Y, Chapagain P, Lee DJ, Blanton SH, Liu XZ. Genetic basis of hearing loss in Spanish, Hispanic and Latino populations. Gene 2018; 647:297-305. [PMID: 29331482 PMCID: PMC5806531 DOI: 10.1016/j.gene.2018.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/02/2018] [Accepted: 01/06/2018] [Indexed: 12/13/2022]
Abstract
Hearing loss (HL) is the most common neurosensory disorder affecting humans. The screening, prevention and treatment of HL require a better understanding of the underlying molecular mechanisms. Genetic predisposition is one of the most common factors that leads to HL. Most HL studies include few Spanish, Hispanic and Latino participants, leaving a critical gap in our understanding about the prevalence, impact, unmet health care needs, and genetic factors associated with hearing impairment among Spanish, Hispanic and Latino populations. The few studies which have been performed show that the gene variants commonly associated with HL in non-Spanish and non-Hispanic populations are infrequently responsible for hearing impairment in Spanish as well as Hispanic and Latino populations (hereafter referred to as Hispanic). To design effective screening tools to detect HL in Spanish and Hispanic populations, studies must be conducted to determine the gene variants that are most commonly associated with hearing impairment in this racial/ethnic group. In this review article, we summarize gene variants and loci associated with HL in Spanish and Hispanic populations. Identifying new genetic variants associated with HL in Spanish and Hispanic populations will pave the way to develop effective screening tools and therapeutic strategies for HL.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Amit P Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Desiree Nguyen
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Debbie R Pan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Vasanti M Jhaveri
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jason R Rudman
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Arjuna Dharmaraja
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Yong Feng
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China
| | - Prem Chapagain
- Department of Physics and Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - David J Lee
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Susan H Blanton
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China; Tsinghua University School of Medicine, Beijing 10084, China; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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11
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Sun J, Hao Z, Luo H, He C, Mei L, Liu Y, Wang X, Niu Z, Chen H, Li JD, Feng Y. Functional analysis of a nonstop mutation in MITF gene identified in a patient with Waardenburg syndrome type 2. J Hum Genet 2017; 62:703-709. [PMID: 28356565 PMCID: PMC5489919 DOI: 10.1038/jhg.2017.30] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/30/2017] [Accepted: 02/07/2017] [Indexed: 11/09/2022]
Abstract
Waardenburg syndrome (WS) is an autosomal dominant inherited neurogenic disorder with the combination of various degrees of sensorineural deafness and pigmentary abnormalities affecting the skin, hair and eye. The four subtypes of WS were defined on the basis of the presence or absence of additional symptoms. Mutation of human microphthalmia-associated transcription factor (MITF) gene gives rise to WS2. Here, we identified a novel WS-associated mutation at the stop codon of MITF (p.X420Y) in a Chinese WS2 patient. This mutation resulted in an extension of extra 33 amino-acid residues in MITF. The mutant MITF appeared in both the nucleus and the cytoplasm, whereas the wild-type MITF was localized in the nucleus exclusively. The mutation led to a reduction in the transcriptional activities, whereas the DNA-binding activity was not altered. We show that the foremost mechanism was haploinsufficiency for the mild phenotypes of WS2 induced in X420Y MITF.
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Affiliation(s)
- Jie Sun
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Department of Otolaryngology, First Affiliated Hospital, Xinjiang Medical University, Xinjiang, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Ziqi Hao
- Department of Center Laboratory, Taiyuan Central Hospital, Shanxi, People's Republic of China
| | - Hunjin Luo
- State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
| | - Chufeng He
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Lingyun Mei
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Yalan Liu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China
| | - Xueping Wang
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Zhijie Niu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China
| | - Hongsheng Chen
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China
| | - Jia-Da Li
- State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
| | - Yong Feng
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Hunan, People's Republic of China.,Province Key Laboratory of Otolaryngology Critical Disease, Xiangya Hospital, Central south University, Hunan, People's Republic of China.,Department of Center Laboratory, Taiyuan Central Hospital, Shanxi, People's Republic of China.,State Key Laboratory of Medical Genetics, Central South University, Hunan, People's Republic of China
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