Loss of heterozygosity in acute leukemia: evidence of frequent submicroscopic deletions.

Although chromosomal abnormalities are detected by conventional cytogenetic analysis (CCA) in 40-60% of patients with acute myeloid leukemia (AML), cryptic chromosomal deletions may only be detected by molecular analysis. To determine their frequency, we studied 74 cases of AML by microsatellite allelotype assay using 35 microsatellites spanning eight chromosomal regions known to be frequently involved in AML. In 42 (57%) we found DNA imbalance at the screened loci.

Submicroscopic deletions at 7q region are associated with recurrent chromosome abnormalities in acute leukemia.

Background And Objectives: Loss of heterozygosity (LOH) on the long arm of chromosome 7 (7q) has been frequently reported in several types of human cancer including hematologic malignancies. Moreover, monosomy of chromosome 7 and 7q deletions have been associated in acute myeloid leukemia (AML) with aggressive disease and poor prognosis.

Design And Methods: Using a panel of 11 polymorphic microsatellite markers at bands 7q21-q36, we investigated fifty patients (acute myeloid leukemia [AML], n=33 and acute lymphoid leukemia [ALL], n=17) for LOH, a hallmark of possible involvement of tumor suppressor genes.