SLC26A4 mutation spectrum associated with DFNB4 deafness and Pendred's syndrome in Pakistanis.

Pendred's syndrome (PDS) is an autosomal-recessive disorder characterized by sensorineural hearing loss and goiter. PDS is caused by mutations of the SLC26A4 gene encoding pendrin, a transmembrane exchanger of Cl(-), I(-) and HCO(3)(-), which is expressed in the thyroid and inner ear. SLC26A4 mutations can also be associated with non-syndromic deafness, DFNB4.