Clinical management of polycystic kidney disease.

ADPKD is caused by mutations in two genes:1,2 • PKD1 on chromosome 16p13.3, and • PKD2, on chromosome 4q21-23. The proteins encoded by PKD1 and PKD2 are polycystin-1 and polycystin-2 (Fig 1).3 Polycystin-1 is probably involved in protein-protein or proteincarbohydrate interactions. Polycystin-2 is a nonselective cation channel that can conduct calcium ions. Mutations in either PKD1 or PKD2 produce identical clinical manifestations and polycystin-1 and polycystin-2 may be part of a common pathway. Although PKD1 and PKD2 are clinically indistinguishable, PKD2 mutations are associated with fewer complications and a longer renal survival (Fig 2).4