PKD2 and autosomal dominant polycystic kidney disease: 6,7 In patients with mutations in PKD2, a milder clinical course compared to PKD1 patients, fewer renal cysts and milder hypertension (HTN) lead to delayed progression to end-stage kidney failure.8 A high level of allelic heterogeneity has been observed among ADPKD patients, with over 2300 and 270 germline variants reported to date in PKD1 and PKD2, respectively in the Autosomal Dominant Polycystic Kidney Mutation Database (PKDB; http://pkdb.mayo.edu/), excluding our most recent data.