MEN2 Phenotype Definitions

The ‘Comments’ for each database entry may contain more MEN2 phenotype information.

The MEN2A, MEN2B, FMTC, and Unclassified phenotype definitions were derived from the international RET consortium guidelines for classification of MEN2 disease phenotypes. Note: these definitions may lead to two different phenotype designations (e.g. FMTC and MEN2A) for the same mutation, depending on the clinical symptoms per family.

MEN2A: Family (or individual) with MTC, and at least one individual developing HPT, pheo, or both.

MEN2B: MTC (with or without pheo) and characteristic clinical features: mucosal ganglioneuromas, GI ganglioneuromas, eye abnormalities including CNT, and skeletal abnormalities including marfanoid body habitus.

FMTC: Four or more family members with MTC only. No clinical evidence of Pheo, HPT, or any MEN2B-specific clinical features in affected or at-risk family members.

Unclassified: A family (or individual) with suspected or known hereditary MEN2 disease who do not meet the clinical criteria to be classified by a specific MEN2 syndrome.

Unknown: Not enough clinical information to conclusively determine the MEN2 Phenotype. It is "unknown" if the individualís or familyís phenotype is due to MEN2 disease or due to other causes.

No MEN2 disease: No known reports of the sequence change causing MEN2 disease.