translocation in CML (Chronic Myologenous Lukemia):
Standard Chromosomes 9
& 22 are shown at left: they are subject to
breakage at the abl and bcr loci,
respectively. The so-called Philadelphia Chromosome is detectable
cytologically as an extra G-group
chromosome due to the apparent shortening of the F-group Chromosome
22 by a reciprocal exchange with Chromosome 9.
Juxtaposition of the abl and bcr loci
interferes with cancer suppressor genes (oncogenes),
and results in a Chronic Myologenous Leukemia.
Philadelphia Chromosome was one
of the first genetic conditions shown to be associated with