All are seen in MEN IIA syndrome except: (A) Medullary carcinoma of thyroid is seen in 100% of the patients, (B) 40 - 30% patients have phaeochromocytoms, (C) Caused by loss of function mutation in II protooncogene, (D) Primary hyperparathyroidism is the most variable feature of MEN II A syndrome
Answer is C. Answer- C. Caused by loss of function mutation in II protooncogeneMEN-2A or Sipple syndrome, is characterized by pheochromocytoma, medullary carcinoma of the thyroid, and parathyroid hyperplasia.Parathyroid hyperplasia and evidence of hypercalcemia or renal stones.MEN-2A is clinically and genetically distinct from MEN-I and is caused by germline gain-of-function mutations in theRET proto-oncogene on chromosome l0qll.2.40% to 50% have pheochromocytomas.Primary hyperparathyroidism is the most variable feature of MEN 2A syndrome.