Fluorescence in situ hybridization studies: Break apart or not?

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AML-M2 with der(18)t(1;18)(q2?;p11.3) in addition to t(8;21) and del(9q)

We report a case of Acute Myeloid Leukemia with clinical features suggestive of AML-M3 and 46,XX,t(8;21),del(9q),der(18)t(1;18) karyotype leading to the final diagnosis AML-M2 in light of t(8;21). The Deletion (9q) is a frequent secondary anomaly to the t(8;21)(q22;q22) in AML-M2. In addition to these two AML-M2 related rearrangements we also observed der(18)t(1;18)(q2?;p11.3) which may be an unusual rearrangement. This rearrangement resulted into partial trisomy of chromosome #1(q2?) without the loss of any part of chromosome 18, morphologically. Rearrangements of long arm of chromosome 1 that result in complete or partial trisomy for 1q mostly involved the region q25-q32, which may confer a proliferation advantage

Loss of sex chromosome in acute myeloid leukemia

Loss of sex chromosomes has been reported in normal and malignant marrows and its frequency increases with age in both situations. It is not clear whether the sex chromosome loss is a critical mutational event for neoplastic transformation or a genetic change related to ageing. The present study was undertaken to analyze incidence of loss of sex chromosomes in leukemia patients. Karyotypic analysis in bone marrow cells was carried out in total 270 AML patients registered at G.C.& R.I. during January 2000 to October 2003. Out of 270, 22 patients had loss of sex chromosome in addition to other disease specific chromosomal abnormalities. Out of 22 patients, 50% (11 of 22) were of the pediatric age (up to 14 years), and only 10% (3 of 22) patients were above the age of 50 years, maximum age being 65 years. On follow-up, only in patients with pathological remission normal 46XX/XY karyotypes were seen. Whereas in patients with persistent leukemic activity, clones with loss of sex chromosome were observed. The results indicate that sex chromosome loss in these cases may be equivalent of a clonal cytogenetic process rather than related to ageing process