The exact cause of sporadic MTC remains unknown, but it is often associated with mutations in the RET proto-oncogene. Hereditary forms of MTC are part of multiple endocrine neoplasia (MEN) syndromes, specifically MEN 2A and MEN 2B. These genetic syndromes are inherited in an autosomal dominant manner, meaning that a single copy of the altered gene in each cell is sufficient to increase cancer risk.
