Genetic screening revealed usher syndrome in a paediatric Chinese patient

Abstract

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.

Keywords:

• Usher syndrome
• hearing loss
• MYO7A
• mutation
• retinitis pigmentosa

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

X. Z. L.’s research is supported by National Institutes of Health/National Institute on Deafness and Other Communication Disorders (R01 DC05575, R01 DC01246 and R01 DC12115).