Genetic screening revealed usher syndrome in a paediatric Chinese patient

Introduction: Usher syndrome (USH) is the most common cause of hereditary deaf-blindness. Three clinical subtypes have been classified. USH type I is the most severe subtype characterized by congenital severe-to-profound hearing loss, retinitis pigmentosa and vestibular dysfunction. Methods: One family was analyzed and the analysis included the combination of a custom capture/next-generation sequencing panel of 180 known deafness gene, Sanger sequencing and bioinformatics approaches. Results: Compound heterozygous mutations in the MYO7A gene: a known missense mutation c.494C > T (p.Thr165Met) and a novel missense mutation c.6113G > A (p.Gly2038Glu) were identified in a proband. This Chinese hearing-impaired child was misdiagnosed as non-syndromic hearing loss which was later changed to the diagnosis of USH type I after comprehensive audiometric, vestibular and ophthalmological examinations at 9 years old. Conclusions: Due to the features of genetic heterogeneity and variation in clinical manifestation, molecular diagnosis and ophthalmological examinations by skilled ophthalmologists with knowledge of USH should be suggested as a routine assessment which may improve the accuracy and reliability of etiological diagnosis for hearing loss.