Hereditary hamartomatous syndromes include Peutz–Jeghers syndrome (PJS, with mutations in LKB1/STK11), PTEN-hamartoma tumor syndrome (PHTS, with mutations in PTEN), and juvenile polyposis syndrome (JPS, with mutations in BMPR1A or SMAD4) [77]. This evidence concerns the gene BMPR1A and juvenile polyposis syndrome.