Pendred syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss, and inner ear malformations such as an enlarged vestibular aqueduct, goiter, and abnormal organification of iodide.[1] It is caused by mutations in SLC26A4 gene, which encodes pendrin (a transporter of chloride, bicarbonate and iodide).[2] Pendrin is not only expressed in the inner ear and thyroid, but also plays an important role in mediating the secretion of bicarbonate into the kidney.[3,4] Therefore, in the absence of pendrin, bicarbonate retention and metabolic alkalosis may occur. The gene discussed is SLC26A4; the disease is Pendred syndrome.