Together, mutations in Pkd1 and Pkd2 account for 78% and 15% of ADPKD cases, respectively, leaving 7% of cases undetected by these two genes.[6]Pkd1’s expansive gene length, featuring 46 exons, encodes polycystin-1 (PC1)—a protein integral to calcium signaling and essential for maintaining tubular epithelial cell polarity and function, with its 4303 amino acid residues. Here, PKD1 is linked to autosomal dominant polycystic kidney disease.