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Huang Y, Li L, Pan L, Ling X, Wang C, Huang C, Huang Y. Non-syndromic enlarged vestibular aqueduct caused by novel compound mutations of the SLC26A4 gene: a case report and literature review. Front Genet 2023; 14:1240701. [PMID: 37745850 PMCID: PMC10512862 DOI: 10.3389/fgene.2023.1240701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023] Open
Abstract
Enlarged vestibular aqueduct is an autosomal genetic disease mainly caused by mutations in the SLC26A4 gene and includes non-syndromic and syndromic types. This study aimed to identify genetic defects in a Chinese patient with non-syndromic enlarged vestibular aqueduct (NSEVA) and to investigate the impact of variants on the severity of non-syndromic enlarged vestibular aqueduct. A male patient with NSEVA, aged approximately 6 years, was recruited for this study. The clinical characteristics and results of auxiliary examinations, including laboratory and imaging examinations, were collected, and 127 common hereditary deafness genes were detected by chip capture high-throughput sequencing. Protein structure predictions, the potential impact of mutations, and multiple sequence alignments were analyzed in silico. Compound heterozygote mutations c.1523_1528delinsAC (p.Thr508Asnfs*3) and c.422T>C (p.Phe141Ser) in the SLC26A4 gene were identified. The novel frameshift mutation c.1523_1528delinsAC produces a severely truncated pendrin protein, and c.422T>C has been suggested to be a disease-causing mutation. Therefore, this study demonstrates that the novel mutation c.1523_1528delinsAC in compound heterozygosity with c.422T>C in the SLC26A4 gene is likely to be the cause of NSEVA. Cochlear implants are the preferred treatment modality for patients with NSEVA and severe-to-profound sensorineural hearing loss Genetic counseling and prenatal diagnosis are essential for early diagnosis. These findings expand the mutational spectrum of SLC26A4 and improve our understanding of the molecular mechanisms underlying NSEVA.
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Affiliation(s)
- Yunhua Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Linlin Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Liqiu Pan
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Xiaoting Ling
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Chenghan Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Chaoyu Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
| | - Yifang Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Guangxi Medical University, Nanning, Guangxi, China
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Abstract
PURPOSE OF REVIEW The increased availability of next generation sequencing has enabled a rapid progress in the discovery of genetic variants associated with vestibular disorders. We have summarized molecular genetics finding in vestibular syndromes during the last 18 months. RECENT FINDINGS Genetic studies continue to shed light on the genetic background of vestibular disorders. Novel genes affecting brain development and otolith biogenesis have been associated with motion sickness. Exome sequencing has made possible to identify three rare single nucleotide variants in PRKCB, DPT and SEMA3D linked with familial Meniere disease. Moreover, superior canal dehiscence syndrome might be related with variants in CDH3 gene, by increasing risk of its development. On the other hand, the association between vestibular schwannoma and enlarged vestibular aqueduct with variants in NF2 and SLC26A4, respectively, seems increasingly clear. Finally, the use of mouse models is allowing further progress in the development gene therapy for hearing and vestibular monogenic disorders. SUMMARY Most of episodic or progressive syndromes show familial clustering. A detailed phenotyping with a complete familial history of vestibular symptoms is required to conduct a genetic study. Progress in these studies will allow us to understand diseases mechanisms and improve their current medical treatments.
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