Multiple endocrine neoplasia type 2A(MEN2A)is an autosomal dominant cancer syndrome that is characterized by medullary thyroid carcinoma(MTC),pheochromocytoma(50%-60% of cases),and hyperplasia of the parathyroid glands(20%-30% of cases).MEN2A comprises a heterogeneous group of neoplastic disorders that most commonly have a single missense substitution of the Ret proto-oncogene(RET)involving exons 10 and 11.Here,we reported a novel case of MEN2A associated with two variations in two distinct genes,Cys634Gly in RET and a rare Ser73Gly substitution in succinate dehydrogenase,subunit D(SDHD).Because the patient presented with medullary thyroid carcinoma and pheochromocytoma but without parathyroid gland involvement,we speculated that this clinical feature could be correlated with the two substitutions.This is the first report of a MEN2A case involving two different changes one in the RET gene and the other in the SDHD gene.
