ABSTRACT
OBJECTIVE: To evaluate children with acute lymphoblastic leukemia (ALL) showing resistance to immediate induction chemotherapy in relation to conventional and advanced cytogenetic analysis. METHODS: This work was conducted on 63 ALL children (40 males and 23 females) with age range 4.5 months-16 years (mean = 7.76 years). They included 37 cases attained true remission and 26 complicated by failure of remission, early relapse or death. They were subjected to history, clinical examination and investigations including CBC, BM examination, karyotyping, FISH for translocations and flowcytometry for immunophenotyping and minimal residual disease diagnosis. RESULTS: Cases aged 50.000/mm3 also showed better but non-significant remission rates. Most of the present cases were L2 with better remission compared to other immunophenotypes. Forty informative karyotypes were subdivided into 15 hypodiploid, 10 pseudodiploid, 8 normal diploid and 7 hyperdiploid cases; the best remission rates were noticed among the most frequent ploidy patterns. Chromosomes 9, 11 and 22 were the most frequently involved by structural aberrations followed by chromosomes 5, 12 and 17. Resistance was noted with aberrations not encountered among remission group; deletions involving chromosomes 2p, 3q, 10p and 12q; translocations involving chromosome 5; trisomies of chromosomes 16 and 21; monosomies of 5 and X and inversions of 5 and 11. CONCLUSION: Some cytogenetic and molecular characterizations of childhood ALL could add prognostic criteria for proper therapy allocation.