Identifications of the novel mutants on MYO7A in a family with non-syndromic hereditary deafness

Abstract

Objective:To identify the deaf-causing mutation by the genetic analysis in a family with non-syndromic hereditary deafness. Methods:Medical history collection, hearing, vision, and genome whole-exome sequencing were performed on the members of the deaf family. Results:Two mutation sites were identified in the MYO7A gene, namely c.1183C>T and 1496T>C, of which c.1183C>T has a small number of foreign literature reports, and 1496T>C is a newly discovered mutation site. According to ACMG mutation guideline showed that these two mutations were pathogenic mutations of the proband. Sanger sequencing verified that c.1183C>T was derived from the father, and 1496T>C was derived from the mother. These two mutation sites were not found in the healthy population in the Exome Sequencing Project（ESP6500） database, 1000 Genomes Project database, and the Gnomad database. Moreover, the second child in this family included a heterozygous mutation of c.1183C>T and 1496T>C and was confirmed to become severe sensorineural deaf. Conclusion:A new pathogenic compound heterozygous mutation in the MYO7A gene has been discovered, which provides more diagnostic evidence for the autosomal recessive non-syndromic deafness caused by the MYO7A gene mutation and improves the prenatal gene diagnosis in high-risk families for mutation carriers to reduce congenital disabilities.