The role of NCC in regulating blood pressure has been established by the discovery of inactivating mutations of the SLC12A3 gene, which cause Gitelman’s syndrome, an inherited disorder that is the mirror image of FHHt, with arterial hypotension, renal salt wasting and hypokalemic metabolic alkalosis (OMIM #263800)6,7. Here, SLC12A3 is linked to Gitelman syndrome.