A De Novo Mutation in SOX10 in a Chinese Boy with Waardenburg Syndrome Type 2

Waardenburg syndrome is an autosomal dominant inherited syndromic hereditary hearing loss characterized by varying combinations of sensorineural hearing loss and abnormal pigmentation of the hair, skin, and inner ear. The aim of this study was to analyze the clinical phenotypes and genetic variants of a Chinese boy with Waardenburg syndrome type 2 and to explore the possible molecular pathogenesis of Waardenburg syndrome type 2. Clinical, audiological, and ophthalmologic evaluations were performed on the proband. Clinical data from the principal members in the proband’s family were collected through questionnaires. Genetic analysis was conducted, including targeted next-generation sequencing of 144 known deafness genes, Sanger sequencing, and bioinformatic analysis. Waardenburg syndrome type 2was diagnosed in a 4-year-old boy according to the Waardenburg Syndrome Consortium Criteria. The novel missense mutation c.426G>T (p.Trp142Cys) was identified in SOX10 in the proband but was absent in his parents and the controls. A de novo missense mutation in SOX10 was the genetic cause of Waardenburg syndrome type 2 in the proband, which was useful for the molecular diagnosis of Waardenburg syndrome type 2.