SLC26A4 does not transport I- from cytosol to extracellular region

Solute carrier (SLC) genes that code chloride (Cl-)/bicarbonate (HCO3-) exchanger proteins are in the SLC4 and SLC26 families. SLC26A4 (pendrin) is thought to act as a chloride/anion exchanger but in the thyroid and inner ear, it also contributes to the conditioning of the endolymphatic fluid by mediating iodide (I-) transport. Defects in SLC26A4 can cause Pendred syndrome (PDS; MIM:274600), an autosomal recessive disorder characterised by congenital sensorineural hearing loss in association with thyroid goiter. Mutations causing PDS include F667C, L236P, T416P, E384G and H723R (Everett et al. 1997, Van Hauwe et al. 1998, Coyle et al. 1998, Usami et al. 1999).

编码氯离子（Cl-）/碳酸氢根离子（HCO3-）交换蛋白的载体蛋白基因位于SLC4和SLC26家族中。SLC26A4（pendrin）被认为充当氯离子/阴离子交换器，但在甲状腺和内耳中，它还通过介导碘离子（I-）转运，参与对内淋巴液条件的调节。SLC26A4基因的缺陷可导致Pendred综合征（PDS；MIM:274600），这是一种常染色体隐性遗传性疾病，其特征为与甲状腺肿大相关的先天性感音神经性听力丧失。引起PDS的突变包括F667C、L236P、T416P、E384G和H723R（Everett等人，1997年，Van Hauwe等人，1998年，Coyle等人，1998年，Usami等人，1999年）。