Allelotype analysis of the myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a group of clonal hematologic disorders found predominantly in the elderly. The molecular mechanisms underlying th e development of MDS remain obscure. In order to begin to identify tumor su ppressor genes involved in these disorders, we performed a detailed microsa tellite allelotype of chromosomal deletions associated with MDS. DNAs from both bone marrow and peripheral blood of 32 MDS patients were studied using 84 highly informative microsatellite markers on all autosomal arms, exclud ing the short arms of the acrocentric chromosomes. A high percentage of los s of heterozygosity (LOH) was identified on chromosome 5q (40% of informati ve cases), 7q (45%), 17p (23%) and 20q (20%), which corresponds to the most common cytogenetic abnormalities reported in MDS. In addition, a high inci dence of LOH (greater than or equal to 20%) was observed on chromosomal arm s which had not been previously reported including 1p (36%), 1q (35%), and 18q (23%). This extensive allelotype analysis focuses attention on several novel genomic regions that probably contain novel tumor suppressor genes wh ose loss of function contributes to the development of MDS.