Background: Most patients from typical multiple endocrine neoplasia type 1 (MEN1) kindreds harbor mutations in the MEN-1 gene, MEN1. We hypothesized that some patients with atypical endocrine neoplasia would also have mutations in MEN1.
Methods: DNA sequencing analysis of mutations in the coding region of MEN1 was performed with genomic DNA obtained from peripheral blood lymphocytes in a total of 21 patients who had: typical MEN1 (n = 8), clinical features suggestive of MEN1 but without a family history of endocrinopathy (n = 7), and atypical endocrine neoplasia and a family history of endocrinopathy suggestive of MEN1 (n = 6).
Results: All 8 patients with typical MEN1 had mutations in MEN1. None of the 7 patients with features of MEN1, but without a family history of endocrinopathy, had a MEN1 mutation. In contrast, 4 of 6 patients with atypical endocrine neoplasia that included components of MEN1 and a family history of endocrinopathy had mutations in MEN1, including 2 patients with pheochromocytoma.
Conclusions: Genomic mutations in MEN1 may frequently be identified in patients with atypical endocrine neoplasia, especially in the setting of a family history of endocrinopathy. Atypical presentations of MEN1 may include pheochromocytoma.