PKD2 and autosomal dominant polycystic kidney disease: ADPKD is a heterogeneous monogenic disorder resulting from mutations in two genes: PKD1 and PKD2. The PKD1 gene (OMIM 601313), located in chromosome region 16p13.3, consists of 46 exons with an open reading frame of 12,912 bp that encodes the 4,303-amino acid peptide polycystin-1 (PC1)4.