Genetic analysis and clinical investigation of a pedigree with multiple endocrine neoplasia type 2A: A case report.

Multiple endocrine neoplasia 2A (MEN2A) is characterized by the coexistence of tumors that involve two or more endocrine glands within the same patient, and is defined as the occurrence of medullary thyroid carcinoma in association with pheochromocytoma (PHEO) and parathyroid tumors or hyperparathyroidism. The pathogenesis of MEN2A is due to the mutation of a tyrosine kinase receptor that is encoded by the rearrangement during transfection (RET) proto-oncogene. The mutation often occurs in exon 10q11.2. The present study reports the case of a 73-year-old man with severe hypercalcemia, bilateral adrenal PHEO and a thyroid nodule. A genetic panel was obtained, and the RET mutation was indicated. The pedigree of the patient was also studied. Genetic testing of the patient's son indicated heterozygosity for the same mutation at codon 634. The first symptom of the two patients was PHEO, which is uncommon. In addition, varied phenotypes were identified in the two patients. In the present study, the association between the phenotypic variation of the RET gene and the occurrence of MEN2A is discussed.