Barttin (BART)

BART encodes an essential beta subunit for CLC chloride channels. These heteromeric channels localize to basolateral membranes of renal tubules and of potassium-secreting epithelia of the inner ear. Mutations in this gene have been associated with Bartter syndrome with sensorineural deafness.

Expression of barttin was evident in inner and outer stripes of the outer medulla of the kidney, most probably representing thin limbs of Henle loop together with some collecting duct coursing through the outer stripe. In 18.5-day postcoitum fetal mouse cochlea, Bsnd expression was strong and exclusive to the marginal cells of the stria vascularis. In addition to the cochlear signal, Bsnd was expressed in dark cells localized at the base of the crista ampullaris of the vestibular organ.