Polycystic Kidney Disease Polycystic kidney disease (PKD) is a systemic hereditary disease characterized by renal and hepatic cysts. There is no known cure for this disease and it results in end-stage renal failure in approximately 50% of affected individuals. Most cases (>95%) are caused by genetic mutations in either the Pkd1 or the Pkd2 gene, which encode polycystin-1 (PC1) and polycystin-2 (PC2), respectively. Although mutations in these genes are causative for PKD, the molecular mechanisms that are altered by these mutations and the molecular events that result in clinical symptoms are still incompletely understood. There is little structural data to describe PC1, PC2, or their interactions with one another. Our laboratory is conducting structure-based functional studies on proteins involved in kidney disease in collaboration with the Ehrlich, Somlo, Hodsdon and Desir Laboratories.