All of the following statements about Philadelphia Chromosome in CML are true, except:
Answer is D (The Philadelphia chromosome with the oncogenic BCR-ABL gene is found on chromosome 9) The Philadelphia chromosome with the oncogenic BCR-ABL gene fusion is the truncated chromosome 22 (and not chromosome 9). The Philadelphia chromosome results from a reciprocal translocation between the ABL-1 oncogene on the long arm of chromosome 9 (region q34) and the breakpoint cluster region (BCR) on the long arm of chromosome 22(region q I I ) This reciprocal translocation, creates an elongated chromosome 9 (der 9), and a truncated chromosome 22. The oncogenic BCR-ABL gene fusion is found on the shoer derivative 22 chromosome (Philadelphia Chromosome). BCR-ABL encodes an oncogenic protein with tyrosine kinase activity (Tyrosine Kinase Inhibitors are therefore used for treatment) In agreement with the International System for Human Cytogenetic Nomenclature (ISCN), this chromosomal translocation is designated as t(9;22)(q34;q11). ABL stands for "Abelson", the name of a leukemia virus which carries a similar protein.
Reciprocal translocation between long arm of chromosome 9 and long arm of chromosome 22
The breakpoint cluster region (BCR) is located on the long arm of chromosome 22
The ABL gene is located on chromosome 9
The Philadelphia chromosome with the oncogenic BCR-ABL gene is found on chromosome 9