Multiple endocrine neoplasia type 1: fresh perspective on clinical features and penetrance.

Multiple endocrine neoplasia type 1 (MEN-1) is an interesting genetic syndrome of polyendocrinopathies. Clinical knowledge about MEN-1 is essential as it appears to be significantly under-diagnosed. New data from several prospective series shows not only that as a many as 40% of patients manifest a first feature of MEN-1 after age 40, but also that as many as a third of gene carriers do not present with hyperparathyroidism as the first feature, as previously believed. Mutational analysis for frequently involved exons of the gene menin on chromosome 11 is now available, but negative results should be interpreted with caution in patients with clinical MEN-1. Disease-specific mortality is significant, arises largely from pancreatic islet carcinoma and malignant thymic carcinoid, and renders this disorder worthy of careful and early prospective diagnosis and treatment.