The CLCNKA and CLCNKB channels are members of the ClC family, which comprises at least 9 mammalian chloride channels. Each is believed to have 12 transmembrane domains and intracellular N and C termini. Recent reports indicated that mutations in the ClC-Kb gene, CLCNKB, expressed in the distal nephron, can cause phenotypes that overlap with either antenatal Bartter syndrome or Gitelman syndrome.