Biallelic nonsense mutations in the otogelin-like gene (OTOGL) in a child affected by mild to moderate hearing impairment

• By using whole exome sequencing, novel mutations in OTOGL gene are identified.
• Possible defect of tectorial membrane due to OTOGL mutations.
• Mutations in OTOGL gene are responsible for mild or moderate hearing impairment.

Hearing impairment is characterized by great genetic heterogeneity. We report the identification, by whole exome sequencing, of two different nonsense mutations (c.1558C>T; p.Gln520* and c.2773C>T; p.Arg925*) in the otogelin-like gene (OTOGL), in a child affected by mild to moderate isolated deafness. Parental genotypes allowed us to conclude that these mutations are present in the compound heterozygous state in the patient. In addition, our clinical data establish that the tectorial membrane and/or the outer hair cells are defective in this form of deafness.