Molecular pathology of multiple endocrine neoplasia type I: Two novel germline mutations and updated classification of mutations affecting MEN1 gene

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorde r characterized by the combined development of tumors in several endocrine glands and other tissues. The MEN1 gene was recently identified and isolate d by positional cloning. This gene was screened in two unrelated MEN1 Spani sh kindreds (with four affected members and seven asymptomatic members) usi ng single-strand conformation polymorphism, DNA sequencing, and restriction enzyme analysis. Two novel germline mutations were identified: a missense in exon 2 (H139R) and a splice-site in intron 9 (1461-2A>C). These findings allowed us to identify the MEN1 carriers among the seven asymptomatic memb ers analyzed. An updated review of the mutations and polymorphisms found in the analysis of the MEN1 gene is provided. The report of all germline muta tions causing MEN1 and easy access to this updated information are both of special diagnostic interest, because this greatly facilitates the task of a ttributing the disorder to a specific mutation found in a given MEN1 family . This is especially helpful in the critical differentiation of missense mu tations from nonsynonymous polymorphisms that fit the pattern of segregatio n of the disease, but do not cause it.