Multiple Endocrine Neoplasia Type 2a

**Definition:** A form of multiple endocrine neoplasia characterized by the presence of medullary carcinoma (CARCINOMA, MEDULLARY) of the THYROID GLAND, and usually with the co-occurrence of PHEOCHROMOCYTOMA, producing CALCITONIN and ADRENALINE, respectively. Less frequently, it can occur with hyperplasia or adenoma of the PARATHYROID GLANDS. This disease is due to gain-of-function mutations of the MEN2 gene on CHROMOSOME 10 (Locus: 10q11.2), also known as the RET proto-oncogene that encodes a RECEPTOR PROTEIN-TYROSINE KINASE. It is an autosomal dominant inherited disease.

**Tree numbers:** - C04.588.322.400.505 - C04.651.600.505 - C04.700.630.505 - C16.320.700.630.505 - C19.344.400.505

**Synonyms:** - MEA 2a - MEA II - Pheochromocytoma And Amyloid-Producing Medullary Thyroid Carcinoma - Sipple Syndrome - Multiple Endocrine Neoplasia, Type IIa - MEA IIa - MEN 2 - MEN 2a - MEN II - MEN IIa - MEN-2A Syndrome - MEN2a - Multiple Endocrine Neoplasia Type 2 - Multiple Endocrine Neoplasms Type 2a - Neoplasia, Multiple Endocrine Type 2a - Neoplasms, Multiple Endocrine Type 2a