Among the HRFDs, ADPKD can present in the perinatal period, over the course of childhood, or in young adulthood, and is caused primarily by mutations in two genes, PKD1 (78% of cases) and PKD2 (15% of cases), with the remaining 5%–10% of cases due to rare mutations in other loci (7). Here, PKD2 is linked to autosomal dominant polycystic kidney disease.