Novel deletional mutation of the MEN 1 gene in a kindred with multiple endocrine neoplasia type 1

MEN1 gene mutation in a Japanese kindred with multiple endocrine neoplasia type 1 was examined. A heterozygous deletion involving 29 base pairs in exon 10 (1606del29) was identified in the proband, and the same deletion was found in the affected family members. Most previously reported germline MEN1 gene mutations are nucleotide substitutions and small insertions/deletions, and a large deletion is rare. The hairpin structure mediated by an incomplete palindromic sequence at deletion termini is the most likely mechanism to be associated with the deletion in the present family.