Chromosomal translocation seen in CML is:: (A) 2:08, (B) 8:14, (C) 9:22, (D) 15:17
Answer is C. Chronic myelogenous leukemia (CML)is characterized by a cytogenetic aberration consisting of a reciprocal translocation between the long arms of chromosomes 22 and 9 . The translocation results in a shoened chromosome 22. This translocation relocates an oncogene called ABL from the long arm of chromosome 9 to a specific breakpoint cluster region (BCR) in the long arm of chromosome 22. The ABL oncogene encodes a tyrosine protein kinase. The resulting BCR/ABL fusion gene encodes a chimeric protein with strong tyrosine kinase activity. The expression of this protein leads to the development of the CML phenotype.