ALLELIC LOSS IN CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA

Acute lymphoblastic leukemia (ALL) is the most frequent cancer encount ered in children. Little is known about the molecular basis of childho od ALL, although the clinical, pathological, and immunophenotypic feat ures have been well documented. To understand the role of tumor suppre ssor genes (TSGs) in the development of this disease, we performed a d etailed allelotype analysis. Twenty-nine patients (24 pre-B and 5 of T -cell lineage) were investigated for loss of heterozygosity (LOH), usi ng 49 highly polymorphic markers distributed over 13 chromosomal arms which are known or postulated to contain TSGs. The highest rates of al lelic losses were observed in chromosomes 9p and 12p which were delete d in 29 and 32% of the informative patients, respectively. These are a mong the most frequent alterations found in childhood ALL. Other losse s were found at a lower frequency in chromosomes 6p, 6q, 9q, 17p, and 17q. No LOH was found at chromosomes 3p, 5q, 11p, 11q, 13q and 18q in any patient. These results suggest that many TSGs may be involved in t he development of childhood ALL. (C) 1997 Elsevier Science Ltd.