PKD2 and autosomal dominant polycystic kidney disease: ADPKD is the most common (approximately 1:1000) and is typically adult-onset; PKD1 (approximately 79%) and PKD2 (approximately 15%) are the major genes, but mutations to at least six other loci are minor causes (ALG5, ALG8, ALG9, GANAB, DNAJB11, and IFT140).3, , , , , , , –11PKD1 and PKD2 encode polycystin-1 and -2 (PC1 and PC2), which form a functional complex at the primary cilium.