According to the results, 37.5% (17 out of 45) of the MTC index patients had nine distinct RET germline mutations, including p.C634R (35.3% in 6 patients), p.M918T (17.6% in 3 patients), p.C634Y (11.8% in 2 patients), p.C634F (5.9% in 1 patient), p.C611Y (5.9% in 1 patient), p.C618R (5.9%-in 1 patient), p.C630R (5.9%-in 1 patient), and p.L790F (5.9%-in 1 patient). The gene discussed is RET; the disease is medullary thyroid gland carcinoma.