This group includes hereditary non polyposis colorectal cancer, also known as Lynch Syndrome (LS), adenomatous (familial adenomatous polyposis [FAP] and MUTYH-associated polyposis [MAP]) and hamartomatous (Peutz-Jeghers Syndrome [PJS], Juvenile Polyposis Syndrome [JPS], PTEN-Hamartomatous Tumor Syndrome [PHTS]) polyposis syndromes [2]. The gene discussed is PTEN; the disease is juvenile polyposis syndrome.