PKD2 and autosomal dominant polycystic kidney disease: The mutation in either of two genes mainly contributed to the development and progression of ADPKD (3): PKD1 and PKD2. PKD1 encodes a large, multidomain integral membrane protein, polycystin-1 (PC1) (4), and PKD2 encodes a calcium ion channel of the transient receptor potential family, polycystin-2 (PC2) (5, 6).