Delineation of a 6 cM commonly deleted region in childhood acute lymphoblastic leukemia on the 6q chromosomal arm

Deletion of the long arm of human chromosome 6 in acute lymphoblastic leukemia (ALL) has been shown by cytogenetic studies in 4-11% of cases. To characterize further the region of deletion and to precisely establish its frequency, we studied loss of heterozygosity (LOH) in 120 children with ALL using polymorphic markers located from the 6q14-15 chromosomal band to the telomere. LOH was detected in eight patients. A single region of LOH, flanked distally by D6S1594 and proximally by D6S301 was detected. These DNA markers are separated by 6 cM and are approximately located at the 6q21-22 band. Our present results delineate a region that is likely to contain a tumor-suppressor gene involved in a subset of childhood ALLs.