C634Y mutation in RET-induced multiple endocrine neoplasia type 2A: A case report

Multiple endocrine neoplasia type 2 (MEN2) is a rare, autosomal dominant endocrine disease. Currently, the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis. Once an RET carrier is detected, family members should be screened to enable early detection of medullary thyroid carcinoma, pheochromocytoma, and hyperparatitity. Among these, medullary thyroid carcinoma is the main factor responsible for patient mortality. Accordingly, delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners.

Herein, we present RET proto-oncogene mutations, clinical characteristics, and treatment strategies in a family with MEN2A. A family study was conducted on patients diagnosed with MEN2A. DNA was extracted from the peripheral blood of family members, and first-generation exon sequencing of the RET proto-oncogene was conducted. The C634Y mutation was identified in three family members spanning three generations. Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas. A 9-year-old child harboring the gene mutation was diagnosed with medullary thyroid carcinoma. Surgical resection of the tumors was performed. All family members were advised to undergo complete genetic testing related to the C634Y mutation, and the corresponding treatments administered based on test results and associated clinical guidelines.

Advancements in MEN2A research are important for familial management, assessment of medullary thyroid cancer invasive risk, and deciding surgical timing.