SLC26A4 and Pendred syndrome: It was reported that mutation in SLC26A4 was not only associated with the common causes of non-syndromic SHL in many ethnic populations [5–9], also biallelic mutations in SLC26A4 could cause Pendred syndrome (PDS), the most common form of syndromic deafness, which accounts for approximately 10% of hereditary hearing impairment [7].