Which of the following mutation seen in Cowden syndrome?: (A) PTCH mutation, (B) PTEN mutation, (C) STK11 mutation, (D) SMAD4 mutation
Answer is B. Ans. b. PTEN mutationRef: Robbins and Cotran Pathologic Basis of Disease 9th Ed; Page No-291Tumor suppressor genes and associated with syndromesGeneProteinFunctionFamilial syndromesPTCHPatchedInhibitor of Hedgehog signalingGorlin syndrome (basal cell carcinoma, medulloblastoma, several benign tumors)PTENPhosphatase and tensin homologueInhibitor of PI3K/AKT signalingCowden syndrome (variety of benign skin, Gl, and CNS growths; breast, endometrial, and thyroid carcinoma)STK11Liver kinase B1 (LKB1) or STK11Activator of AMPK family of kinases; suppresses cell growth when cell nutrient and energy levels are lowPeutz-Jeghers syndrome (Gl polyps, Gl cancers, pancreatic carcinoma and other carcinomas)SMAD4SMAD4Component of the TGFP signaling pathway, repressors of MYC and CDK4 expression, inducers of CDK inhibitor expressionJuvenile polyposis, pancreatic carcinoma