Is thyroidectomy necessary in RET mutations carriers of the familial medullary thyroid carcinoma syndrome?
GROUND: The results and consequences of genetic testing in a family with familial medullary thyroid carcinoma (FMTC) are described. METHODS: In the screening of relatives, serum calcitonin is replaced by RET mutation analysis that was performed in families suspected of hereditary medullary thyroid carcinoma (MTC). In 4 of 10 families, mutation in exon 10 was found in codon 611. RESULTS: One hundred fifty persons belonging to 30 families were tested, of which 10 families were carriers of RET mutation in exon 10. In 1 of these families with MTC only, 2 brothers were gene carriers of a RET codon 611 mutation and lived without any sign of MTC. One is aged 79 years, and the other died at the age of 71 of other causes. CONCLUSIONS: The results indicate that the gene carrier in families with MTC without other endocrine tumors (FMTC) exhibits a highly variable disease course. A 611 codon mutation is most often a rather mild and slow progression form of MTC. Because 2 gene carriers were still a
