Abnormalities of the long arm of chromosome 6 in childhood acute lymphoblastic leukemia.

摘要: To determine the biologic significance of structural rearrangements long arm chromosome 6(6q) in acute lymphoblastic leukemia (ALL) at diagnosis, we studied 412 consecutive children whose leukemic cell chromosomes had been completely banded and identified 45 (11%) with this abnormality. The cases were divided into del(6q) only (n = 11), numerical abnormalities 4), 23), 6q translocations 7). breakpoints subgrouped: del(6)(q15q21) 11 cases, del(6) (q13q21) six, del(6)(q21q23) four, del(6)(q15) del(6)(q15q23) three, other deletions 10 cases. Notably, all these encompassed 6q21 band, suggesting that might be locus a recessive tumor suppressor gene, absence which contributes to malignant transformation or proliferation. Among seven translocations, previously unidentified nonrandom translocation, t(6;12)(q21;p13) was noted two an early pre-B immunophenotype. Clinical features event-free survival similar among without abnormalities. Overall, less likely than those abnormality have immunophenotype (P .03). T- immunophenotypes equally represented However, four 12p ALL three 9p T-cell lack specificity for particular may imply gene genes affected by are broadly active multistep process lymphoid leukemogenesis. relatively high frequency microscopically visible indicates need molecular studies identify submicroscopic deletions.