A. Giovannetti, Luisella Cianferotti, Edda Vignali, Claudio Marcocci, Filomena Cetani, Paola Cerrai, Paolo Miccoli, Elena Pardi, Aldo Pinchera, Simona Borsari, and A. Picone
We report nine mutations of the multiple endocrine neoplasia type 1 (MEN1) gene in sporadic parathyroid adenomas. Six of them have not previously been described: E60X, P32R, 261delA, 934+2T-->G, S443P, and 1593insC. The tissue samples were initially submitted to LOH analysis at 11q13 followed by SSCP screening of LOH-positive samples. Mutations were identified by direct sequencing and subcloning. Three (E60X, P32R, and 261delA) were in exon 2, one (934+2bp) in the splice junction of exon 5, one (S443P) in exon 9, and one (1593insC) in exon 10. The 3 mutations in exon 2 were associated with loss and/or creation of a restriction site. The corresponding germline sequence of the MEN1 gene was normal. Most mutations would likely result in a nonfunctional menin protein, and therefore in the loss of a tumor suppressor protein.