The mother was 33 year old; she had multicystic bilateral disease without affected family members, and showed a de novo missense variant p.(Cys331Thr) in PKD2. The father was a healthy 44 years old man with no signs of kidney cystic disease at ultrasound, and showed a variant in PKD1, p.(Ser123Thr), and a second variant in PKD2, p.(Arg872Gly). This evidence concerns the gene PKD1 and cystic kidney disease.