Segmental amplification of 11q23 region identified by flourescence in situhybridization in four patients with myeloid disorders: a review

Four cases with a segmental amplification of 11q23 region were detected by FISH. The amplification was either contiguous amplification on chromosome I l, or multiple markers involving the 11q23 region. The markers were derivat ive chromosomes, or isochromosomes. Amplification of 11q23 region was assoc iated with complex karyotypes at the time of diagnosis or following treatme nt in secondary leukemias. Three were AML cases belonging to either AML-M5a or AML-1 subtypes and one was a myeloproliferative disorder. These cases w ere resistant to treatment. Conventional cytogenetic analysis and fluoresce nce in situ hybridization (FISH) studies using MLL, II painting, or 11 cent romere probes ascertained the segmental amplification. Since the patients d id not respond to treatment the amplification of gene or genes that map to 11q23 may be responsible for the unfavorable prognosis. Hence, this type of amplifications could have clinical significance. (C) 2001 Elsevier Science Inc. All rights reserved.