Mutations in Kirs are associated with various channelopathies; for instance, certain mutations in the ATP-dependent Kir channel Kir6.2 are known to be a cause of neonatal diabetes (Hattersley and Ashcroft, 2005), and mutations in the outer medullary potassium channel Kir1.1 (ROMK) lead to a type of renal failure known as Bartter syndrome (Derst et al., 1997). Here, KCNJ1 is linked to kidney failure.