PKD1 and cystic kidney disease: PKD1 and PKD2 are often the only genes tested when evaluating a patient with a positive family history of ADPKD at the patient age of 20–21 years of age or a patient presenting with accidental findings of renal cysts on imaging or symptomatic manifestations of renal cysts, such as nephrolithiasis or hematuria (Cadnapaphornchai, 2015).