Unicuspid and quadricuspid aortic valves: two case reports and literature review.

There are three cusps in a normally developed aortic valve. Abnormal excavation or fusion, during the embryological development of the aortic valve, results in a varying number of cusps. Bicuspid aortic valve is the most common, but more rarely, unicuspid and quadricuspid aortic valves can be seen.Here, a case of a 16-year-old male with a unicommissural unicuspid aortic valve and a case of a 13-year-old female with a quadricuspid aortic valve were reported.