Genetic and cytogenetic changes in acute lymphoblastic leukemia.

In recent years, a number of non-random chromosomal alterations have been identified in specific populations of acute lymphoblastic leukemic cells of either B-cell or T-cell lineage. The most frequently involved chromosomal sites are 1q, 4q, 6q, 7q, 8q, 9p, 9q, 10q, 11p, 12p, 14q, 19p and 22q. Genes located near frequent breakpoints include c-myc, c-abl and the genes for the T-cell alpha and beta receptors. In addition, approximately 20 other genes potentially involved in the leukemic process are located near less frequently encountered, but consistent, chromosomal breakpoints.