SLC26A4 and Pendred syndrome: Mutations in SLC26A4 cause non-syndromic recessive deafness with an enlarged vestibular aqueduct (DFNB4, [MIM 600791]) and Pendred syndrome (PDS, [MIM 274600]), and are considered to be the most common cause of hereditary hearing loss in East Asia and the second most common cause worldwide2, 3, 4, 5, 6, 7.