Identifying DNA Variants in a Turkish Cohort with Inner Ear Anomalies

To determine the genetic causes of sensorineural hearing loss (SNHL) associated with inner ear anomalies, 11 unrelated Turkish individuals diagnosed with SNHL and an inner ear anomaly using temporal bone computed tomography and inner ear magnetic resonance imaging underwent exome or whole genome sequencing to identify underlying genetic defects. None of the individuals was diagnosed with a recognized syndrome. Four of the 11 probands were homozygous for <i>SLC26A4</i> variants, <i>c.283G>A</i>, <i>c.845G>A</i>, <i>c.1061T>C</i>, and <i>c.1198delT</i>. Another proband was homozygous for a <i>TECTA</i> variant, c.4163G>A. Patients with variants of the <i>SLC26A4</i> gene had bilateral enlarged vestibular aqueduct, bilateral incomplete partition type 2 anomaly, bilateral hypoplastic cochlea and bilateral enlarged vestibular aqueduct plus hypoplastic cochlea anomaly. Patients with the variant <i>TECTA</i> gene had bilateral hypoplastic cochlea. This study identified variants of <i>SLC26A4</i> in 36% of probands with inner ear anomalies. While we identified a variant of the <i>TECTA</i> gene in a proband with cochlear hypoplasia, further studies are needed to see if <i>TECTA</i> variants can cause cochlear malformations.