CHROMOSOMAL INSTABILITY IN MULTIPLE ENDOCRINE NEOPLASIA TYPE-1 - CYTOGENETIC EVALUATION WITH DEB TEST

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant c ondition with high penetrance and variable expressivity, in which tumo rs or hyperplasia occur in two or more endocrine organs. Some authors have investigated chromosomal instability in MEN 1 and MEN 2; the resu lts are controversial. Chromosome analyses were performed on lymphocyt es from seven patients with MEN 1, four healthy first-degree relatives (three of whom were children), six phenotypically normal volunteers, and three patients with Fanconi's anemia. To evaluate chromosomal inst ability we analyzed phytohemagglutinin-stimulated lymphocyte cultures with and without diepoxibutane. We observed an increase in the frequen cy of spontaneous chromosomal alterations in four patients. After the DEB test we found an increase in chromatid breakages, gaps, and exchan ge figures. These findings support the inclusion of the MEN 1 syndrome among the disorders with ''chromosomal instability.''