Endocrine Abstracts

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant genetic disorder characterized by parathyroid adenomas, enteropancreatic endocrine tumors and anterior pituitary adenomas. It is caused by inactivating mutations of the MEN1 tumor suppressor gene, encoding menin (chromosome 11q13). A large family with several members affected were evaluated for clinical and genetic characteristic of MEN1.

The index male patient (42 yr) presented with symptoms of hypoglycemia and hypercalcemia. Abdominal MRI revealed a mass at distal pancreas. Distal pancreatectomy was performed. Glucagon, synaptophysin and chromogranin were positive on immunostaining, but insulin was negative. Total parathyroidectomy was performed and on pathology, parathyroid hyperplasia was diagnosed. His pituitary MRI and hormone levels were normal. Because the index patient had developed two tumor types associated with MEN1, genetic analysis was performed. Genetic analysis identified a novel mutation on chromosome 11q13.1 which was c.218insGGCGGCAC heterozygote.

Case 2 (21 yr) is the son of index case. He had primary hyperparathyroidism. Total parathyroidectomy was performed. Two neuroendocrine tumor was defined at pancreas.

Case 3 (45 yr) is the sister of index case. She had primary hyperparathyroidism with parathyroid hyperplasia.

Case 4 (50 yr) is the other sister of index case. She had primary hyperparathyroidism. She has four non-fonctional neuroendocrine tumor on pancreas, all of which are stable in size.

Case 5 (27 yr) is the son of case 4. He had primary hyperparathyroidism. He went to surgery for parathyroid hyperplasia. He is waiting for pancreas surgery for 21 mm pancreatic neuroendocrine tumor.

Case 6 (24 yr) is the daughter of case 4. Despite in-vitro fertilization methods, she was unable to conceive. After parathyroid surgery, she became pregnant spontaneously.

We conclude that MEN1 in this large family was associated with a previously unidentified mutation of the menin gene. MEN1 genetic analysis facilitates clinical management and provides benefits to patients and families with MEN1.