Novel p.C620L RET Mutation Detected in a Patient with Medullary Thyroid Carcinoma

A patient with an apparent sporadic medullary thyroid carcinoma was tested for RET germline mutations by Sanger sequencing of RET exons 10, 11, and 13-16. The patient was heterozygous for two known mutations causative of Multiple Endocrine Neoplasia type 2 disorder, and both mutations were within codon 620 of RET exon 10, c.1859G > T (p.C620F) and c.1860C > G (p.C620W). In order to determine if these adjacent mutations were in cis or in trans,...