Deletion of long arm of chromosome 7 in myelodisplastic syndromes and therapy related acute myeloid leukemias

Monosomy 7 and deletion of the long arm of chromosome 7 are frequent non-random findings in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), moreover they are present in almost 50% of therapy-related myelodysplasia and therapy-related leukemia (t-MDS and t-AML). We used polymerase chain reaction (PCR) and Southern blotting and hybridization for restriction fragment length polymorphism (RFLP) analysis of the chromosomal region 7q22-7q31.3, where mostly losses of heterozigosity (LOH) have been described in MDS and t-AML. We studied 50 patients affected by MDS and t-AML for LOH in this region. We found LOH in 4 patients (8%), the deletions were found in 7q22.1 for one patient and in 7q31.1 for three more patients.