- Have any self or family history of type 2A or type 2B multiple endocrine neoplasia (MEN 2A or 2B) in the absence of known C-cell hyperplasia (this exclusion includes participants with a family history of MEN 2A or 2B, whose family history for the syndrome is rearranged during transfect [RET]- negative; the only exception for this exclusion will be for participants whose family members with MEN 2A or 2B have a known RET mutation and the potential participant for the study is negative for the RET mutation)