A case of multiple endocrine neoplasia type 2A with a C634A mutation and a L769L polymorphism in RET proto-oncogene

Abstract

Multiple endocrine neoplasia type 2A (MEN2A) is an autosomal dominant syndrome characterized by the presence of a medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism. MEN2A arises due to germline missense mutations of the RET proto-oncogene. Specific RET mutations correlate with the onset of age and the aggressiveness of a medullary thyroid carcinoma. However, the clinical presentation varies even within families, where patients carry the same mutation. Recently, it has been reported that polymorphisms of RET may have a modifier effect on the presentation. We experienced a case of 42-year-old man, whose bilateral pheochromocytoma and medullary thyroid carcinoma were incidentally found. Genetic testing detected a mutation in codon 634 (C634R) and a polymorphism in codon 691 (G691S) of the RET proto-oncogene. His mother, younger brother and his only son had the same mutation and polymorphism. We report this case with a review of the literature about RET gene polymorphisms. (J Kor Endocr Soc 22:453~459, 2007)