- No mutations but an increased frequency of SDHx polymorphisms in patients with sporadic and familial medullary thyroid carcinoma. Montani, M., Schmitt, A.M., Schmid, S., Locher, T., Saremaslani, P., Heitz, P.U., Komminoth, P., Perren, A. Endocr. Relat. Cancer (2005)