A NOVEL GERMLINE MUTATION IN EXON-5 OF THE MULTIPLE ENDOCRINE NEOPLASIA TYPE-1 GENE

The autosomal dominant multiple endocrine neoplasia type 1 (MEN1) synd rome is characterized by neoplasia of parathyroids, anterior pituitary , and gastrointestinal and pancreatic neuroendocrine tissues. Recently the gene responsible for the MEN1 syndrome has been identified on chr omosome region 11q13. Most of the described mutations are nucleotide s ubstitutions and small deletions affecting exons 2 and 3, causing prot ein truncation. Only one mutation in exon 5 has been found, and this c orresponds to a MEN1 sporadic case. Small insertions are also rare. We studied a MEN1 family composed of five members, two of whom were clin ically affected. We found a new germline 1 basepair insertional mutati on affecting the exon 5 of the MEN1 gene in the two members affected i n this MEN1 family.