Multiple endocrine neoplasia type 2 causes

Causes
Mutations in the RET proto-oncogene cause multiple endocrine neoplasia type 2. The protein produced by the RET proto-oncogene gene normally plays an important role in signaling cells to respond to their environment, for example by dividing or maturing. Mutations in this gene cause an overactivation of the protein's signaling function, which can lead to an overgrowth of cells and the formation of tumors characteristic of multiple endocrine neoplasia type 2.

Genetics
Most cases of multiple endocrine neoplasia type 2 are inherited in an autosomal dominant pattern, which means affected people may have affected siblings and relatives in successive generations (such as parents and children). An affected person usually has one parent with the condition. Some cases, however, result from new mutations in the RET proto-oncogene gene. These cases occur in people with no history of the disorder in their family.

Germline mutations are responsible for sporadic MEN 2, while mutations in the cysteine residues in the exons of the RET protein product are common in familial MEN 2.