[Multiple endocrine neoplasia type 2A caused by a p.C618R RET proto-oncogene mutation in a Chinese pedigree].

Objective: To explore the clinical characteristics and significance of RET proto-oncogene screening in multiple endocrine neoplasia type 2A (MEN2A).

Methods: Comprehensive medical history was obtained for 5 members from a 3-generation family from southern China. Clinical investigations have included biochemical testing, imaging, and screening of germline RET proto-oncogene mutations.

Results: Genetic screening has revealed a missense mutation at codon 618(TGC>CGC) of exon 10 in 3 patients(p.C618R), which was consistent with their clinical manifestations. For the 3 individuals, the age at diagnosis was 21, 26 and 36 yr, and the maximum diameter of medullary thyroid carcinoma was 22, 25 and 39 cm, respectively. The 36-year-old female patient initially underwent right total thyroidectomy plus right neck lymph node dissection. Four years later, she again underwent left adrenal tumorectomy and left total thyroidectomy plus left neck lymph node dissection. The 21-year-old male patient underwent right total thyroidectomy plus right modified neck dissection. The follow-up was respectively 146 and 26 months following the initial operation. Two patients still presented elevated calcitonin and had bilateral neck lymph node masses and/or left thyroid masses on imaging examination. The 26-year-old female patient, who presented bilateral thyroid masses and elevated calcitonin, has refused thyroidectomy.

Conclusion: Combined family survey and RET gene screening can facilitate early diagnosis and surgical treatment to improve the prognosis.