A new complex variant Philadelphia chromosome, t(1;9;22)ins(17;22), characterized by fluorescence in situ hybridization in an adult ALL.
A new complex variant Philadelphia chromosome was detected in a 65-year-old man with acute, pre-B, lymphoblastic leukemia (ALL). The classic cytogenetic analysis identified an apparently balanced three-way translocation t(1;9;22)(q25;q34;q11.2). Fluorescence in situ hybridization (FISH) studies confirmed the translocation and showed bcr/abl fusion on the der(22). However, these studies revealed that the distal part of the bcr gene was not translocated onto chromosome 1 at 1q25, but inserted into chromosome 17 at 17p12-13. This complex variant translocation was described as a t(1;9;22)(q25;q34;q11.2)ins(17;22)(p12-13;q11.2q11.2). Secondary changes including +8, an inversion of the derivative chromosome 9, a translocation t(14;20)(q11;q13), and an additional derivative 22 were also identified in most of the abnormal cells. The patient died from systemic fungemia and multiorgan failure 9 months after the diagnosis of ALL. The clinical significance of complex variant Philadelphia chromosomes in ALL is reviewed and discussed.
Fan
Y S
YS
Department of Laboratory Medicine, London Health Sciences Centre, Ont., Canada. fany@lhsc.on.ca
Rizkalla
K
K
Barr
R M
RM
D000328:Adult; D000368:Aged; D002871:Chromosome Banding; D002877:Chromosomes, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D010677:Philadelphia Chromosome; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic