Novel mutation located in EC7 domain of protocadherin-15 uncovered by targeted massively parallel sequencing in a family segregating non-syndromic deafness DFNB23

Abstract

ObjectiveHereditary hearing loss is a clinically and genetically heterogeneous disorder associated with mutations of a large number of diverse genes. In this study we applied targeted capture and massively parallel sequencing to identify the disease-causing gene of a Chinese family segregating recessive inherited deafness. MethodsAfter excluding mutations in common deafness genes GJB2, SLC26A4, mitochondrial m.1555A>G, genomic DNA of the proband of family GDSW24 was subjected to targeted next-generation sequencing. Subsequently, a candidate homozygous mutation was confirmed by Sanger sequencing. ResultsA novel PCDH15 c.2367_2369delTGT/p.V788-homozygous mutation was detected. In this family, no obvious vestibular disorder was found. The in-frame mutation c.2367_2369delTGT is located in the evolutionarily conserved EC7 domain of Protocadherin-15 and was predicted to be pathogenic. ConclusionThe novel homozygous mutation in a family segregating non-syndromic hearing loss family supports previous reported observations that PCDH15 does not only causes Usher syndrome type 1F, but also DFNB23.