Identification of genetic etiology in nonsyndromic hearing loss using targeted next generation sequencing technology

Genetic testing is an important step in the standart care of individuals with hearing loss, In this study, the genetic etiology of autosomal recessive nonsyndromic hearing loss (ARNSHL) in Turkish patients with cochlear implant who had a pedigree suggestive of an autosomal recessive inheritance has been investigated. As a workflow, , a targeted next generation sequencing panel (Illumına TruSightTM Exome) that we briefly called mendelian exome sequencing was performed in nonsyndromic hearing loss patients who were screened for GJB2 previously. In this panel, 2761 genes including 102 deafness genes and a number of genes causing Mendelian disorders were covered. Using this method, causative variants in 21 of 29 families were identified. In seven families, 3 different GJB2 variants were found. Remaining 14 families had 15 different variants in other known NSHL genes (CDH23, DFNB31, GPSM2, LOXHD1, MARVELD2, MYO7A, MYO15A, TMC1, TMIE, USH1G). Eight of these variants are novel. Confirming the usefulness of targeted sequencing approach in NSHL, 72.4 of mutation detection rate was described.