Multiplex primer extension assays were performed to detect the BRAF c.1799 T > A (p.V600E) mutation in melanomas (n = 7), colorectal carcinomas (n = 2), papillary thyroid carcinoma (n = 1) and a case of Langerhans histiocytosis. The gene discussed is BRAF; the disease is thyroid gland papillary carcinoma.