What type of translocation does a Philadelphia chromosome have?
Somatic: BCR-ABL gene fusion The Philadelphia chromosome is a reciprocal translocation involving chromosomes 9 and 22 that is commonly identified in chronic myelogenous leukemia (CML). The break points of the translocation create a fusion of two genes: ABL1 on chromosome 9 and BCR on chromosome 22.
What chromosomal translocation is associated with chronic myelogenous leukemia?
Chronic myelogenous leukemia (CML) is genetically characterized by the reciprocal translocation of chromosome 9 and 22.
What does the Philadelphia chromosome cause?
Philadelphia chromosome (Ph): The chromosome abnormality that causes chronic myeloid leukemia (CML). Abbreviated as the Ph chromosome. The Ph chromosome is an abnormally short chromosome 22 that is one of the two chromosomes involved in a translocation (an exchange of material) with chromosome 9.
Is chronic myelogenous leukemia caused by translocation?
Chronic myeloid leukemia is caused by a rearrangement (translocation ) of genetic material between chromosome 9 and chromosome 22. This translocation, written as t(9;22), fuses part of the ABL1 gene from chromosome 9 with part of the BCR gene from chromosome 22, creating an abnormal fusion gene called BCR-ABL1.
Is Philadelphia chromosome the same as BCR-ABL?
The merged gene is called the BCR-ABL fusion gene. The changed chromosome 22, which contains the BCR-ABL gene, is called the Philadelphia chromosome because that’s the city where researchers first discovered it. The BCR-ABL gene is not the type of mutation that is inherited from your parents.
What causes BCR-ABL?
The swapping of DNA between the chromosomes leads to the formation of a new gene (an oncogene) called BCR-ABL. This gene then produces the BCR-ABL protein, which is the type of protein called a tyrosine kinase. This protein causes CML cells to grow and divide out of control.
Are there any treatments for the BCR-ABL translocation?
There are benefits in therapy when an individual is identified to have the BCR-ABL translocation. In the 1990s, the drug imatinib mesylate was developed as a tyrosine kinase inhibitor able to significantly limit the growth of tumor cells with the translocation.
Where is ABL1 located on the Philadelphia chromosome?
In Philadelphia translocation, the ABL1 region of chromosome-9 is inserted into the ‘BCR’ region of the chromosome-22. The BCR region (Break-point Cluster Region) is about 5.8 kb in size located in the chromosome-22 where the breakpoint occurs.
What is the molecular weight of the Bcr-Abl gene?
This gene encodes for a Bcr-abl fusion protein. Depending on the precise location of fusion, the molecular weight of this protein can range from 185 to 210 kDa. Consequently, bcr-abl is referred to as p210 or p185. Three clinically important variants are the p190, p210, and p230 isoforms.
Which is oncogenic BCR gene translocation in CML?
Philadelphia Chromosome and Oncogenic BCR ABL Gene Translocation in CML. Philadelphia Chromosome (PH) (Philadelphia Translocation, PH and Chronic Myeloid Leukemia – CML) Translocation is a type of structural aberration of the chromosome where a segment of chromosome gets translocated to another chromosome.