Objective:To investigate the molecular characteristics and clinical heterogeneity of Usher syndrome（USH） -related gene variants in patients with hereditary hearing loss in southwest China, providing a basis for early diagnosis and clinical management. Methods:Thirteen patients from twelve families with hearing loss who attended the Affiliated Children's Hospital of Kunming Medical University between January 2017 and March 2021 were enrolled. All patients were identified as carrying USH-related gene variants through next-generation sequencing. Sanger sequencing was performed for all patients and their parents to validate the pathogenic variants. Comprehensive clinical evaluations, including medical history collection, otologic and ophthalmologic examinations, and vestibular function assessments, were conducted. Results:Among the 13 patients, 4 were diagnosed with USH type 1 and 2 with USH type 2. A total of 19 pathogenic or likely pathogenic variants were detected in USH-related genes, including MYO7A,CDH23,USH1C, and USH2A. The causative gene was MYO7A in 3 probands, CDH23 in 5, USH1C in 3, and USH2Ain 2. All patients exhibited an autosomal recessive inheritance pattern. Vestibular dysfunction was observed in 4 patients, and retinitis pigmentosa（RP） in 3 patients. Based on the genotype-phenotype correlation, 6 patients were initially diagnosed with USH, while 7 were classified as having non-syndromic hearing loss（NSHL）. Conclusion:This study revealed the clinical heterogeneity of USH-related gene variants in patients with hereditary deafness in southwest China. Although the clinical manifestations of USH are complex and there are overlapping characteristics between different subtypes, genetic testing provides an important basis for early diagnosis and precise clinical management. Especially for those with typical hearing loss, early genetic diagnosis can provide a window of time for early detection and intervention of retinitis pigmentosa.
Humans ; Usher Syndromes/genetics* ; Myosin VIIa ; Phenotype ; Male ; Female ; Myosins/genetics* ; Mutation ; Cadherins/genetics* ; Child ; Extracellular Matrix Proteins/genetics* ; Adolescent ; Pedigree ; High-Throughput Nucleotide Sequencing ; Cadherin Related Proteins ; Cytoskeletal Proteins ; Cell Cycle Proteins

Objective: To investigate the variation of genes associated with Usher syndrome type 1(USH1)in 136 Chinese deafness families from Henan province. Methods: The data of 136 deafness families tested by next-generation sequencing(NGS) which identified in the center of genetics and prenatal diagnosis of the First Affiliated Hospital of Zhengzhou University from November 2016 to December 2019 were analysized and the variation frequency of six genes related to Usher syndrome type 1(MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2) were summarized. Results: Five deafness families were detected nine pathogenic or likely pathogenic variations in two genes, accounting for 3.7% of all families. Among them, four families were caused by MYO7A variations and one family was caused by CDH23 variation. Meanwhile, seven variations of two genes were reported for the first time. They were c.313delG, c.5257dupA, c.5435A>T, c.5636G>C, c.5722T>G of MYO7A, and c.155_166del, c.4802delA of CDH23. The patients' vision of family 2 and family 3 had no obvious abnormality at present, but according to genetic diagnosis and walking dealy, they were considered to be USH1. Conclusions: MYO7A is the most common caustive gene associated with USH1 in Henan deafness patients, the application of next-generation sequencing technology can make USH1 patients diagnosed earlier before the visual symptoms appear.
China/epidemiology* ; DNA Mutational Analysis ; Deafness/genetics* ; Humans ; Mutation ; Myosin VIIa ; Myosins/genetics* ; Pedigree ; Usher Syndromes/genetics*

OBJECTIVE: To detect potential variants in a family affected with Usher syndrome type I, and analyze its genotype-phenotype correlation. METHODS: Clinical data of the family was collected. Potential variants in the proband were detected by high-throughput sequencing. Suspected variants were verified by Sanger sequencing. RESULTS: The proband developed night blindness at 10 year old, in addition with bilateral cataract and retinal degeneration. Hearing loss occurred along with increase of age. High-throughput sequencing and Sanger sequencing revealed that she has carried compound heterozygous variants of the MYO7A gene, namely c.2694+2T>G and c.6028G>A. Her sister carried the same variants with similar clinical phenotypes. Her daughter was heterozygous for the c.6028G>A variant but was phenotypically normal. CONCLUSION The clinical features and genetic variants were delineated in this family with Usher syndrome type I. The results have enriched the phenotype and genotype data of the disease and provided a basis for genetic counseling.
Child ; Female ; Genetic Variation ; Genotype ; Heterozygote ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; Myosin VIIa ; genetics ; Night Blindness ; etiology ; Pedigree ; Phenotype ; Usher Syndromes ; genetics ; pathology