Adult T-cell leukemia. Chromosome analysis of 15 cases

Chromosome studies was conducted on 15 patients with adult T-cell leukemia. Cells with chromosomal abnormality were seen in 14 of the 15 patients. The modal chromosome number was near diploid range in all the patients. The most common abnormality was 14q+ marker chromosome and partial deletion of the long arm of chromosome 6, i.e., 6q-, which were seen in eight and seven cases, respectively. Donor chromosomes involved in the 14q+ marker chromosome varies, i.e., Yq, #5p, #5q, #9q, #10q or #12q, except for two patients whose donor chromosome origins were unable to determine. The break point in 14q+ marker chromosome was band at q32. The 6q- chromosome was due to a deletion in one patient and interstitial deletion in six patients. A 14q- chromosome having break point at q24 was found in one patient and duplication of Yq chromosome in two patients. In addition, four patients showed a 5q- chromosome or a 9q- chromosome which was due to a translocation or deletion. The significance of these chromosome abnormalities was discussed.