Subjects with biallelic GJB2 mutations were tested for mutations in the SLC26A4 gene to rule out Pendred syndrome as a confounding cause of large vestibular aqueduct syndrome.
Hearing impairment was caused in one family by a novel mutation in the recently identified OTOF (the DFNB9 gene), by a novel Pendred syndrome mutation (Thr193Ile) in another family, and by a GJB2 mutation (35delG also known as 30delG) in the third family.