Brief Report - Conventional and fluorescence  in situ hybridization analysis of three-way complex  BCR-ABL rearrangement in a chronic myeloid leukemia patient

Chromosomal analysis was carried out in bone marrow sample of an 11-year-old girl suspected of myeloproliferative disorder. Conventional G-banding study detected a complex three-way translocation involving 7, 9 and 22, which has resulted in the formation of a variant Philadelphia chromosome causing rearrangement of abl and bcr genes in 87% cells. Fluorescence in situ hybridization (FISH) confirmed the fusion of bcr-abl oncogene. Thus the bone marrow karyotype was observed as 46,XX (13%) / 46,XX,t(7;9;22)(q11;q34;q11) (87%). Hyperdiploidy was present in two cells. In this study, both conventional cytogenetic and FISH diagnosis proved to be significant to identify the variant nature of the Philadelphia chromosome and hyperdiploid condition for introduction of a suitable treatment regimen and estimation of life expectancy of the young girl.

Keywords
BCR-ABL fusion, chronic myeloid leukemia, fluorescence in situ hybridization, t(7;9;22), variant Philadelphia chromosome