Chromosomal abnormalities in adult T-cell leukemia/lymphoma (ATL). A report of six cases with review of the literature.

Chromosomal studies were performed on six patients with adult T-cell leukemia (ATL). Structural abnormalities of chromosome 3 were the most common. In one case a complete loss of the short arm of chromosome 10 (10 p-) was noted while in another case a balanced translocation involving chromosome 10p and 4q was found. These abnormalities have not been previously reported. After reviewing the literature, it was concluded that chromosomes 3, 6, 10, 13, 14, and X were most frequently involved in abnormalities. Specific and consistent chromosomal abnormalities were noted in each study. Therefore, it is hypothesised that the mutation rate for this virus may be higher than first expected. Furthermore, the relative consistency of heterogeneous findings in different localities may reflect a geographic clustering of specific chromosomal abnormalities which may in turn be related to specific and geographically associated viral mutations. To support these suggestions not only are more cytogenetic data required but a molecular evaluation of these patients must be carried out to establish a relationship, if any, between genetic abnormalities and the epidemiology of ATL.