What Is the Philadelphia Chromosome?
Philadelphia chromosome refers to the translocation of the long arm of chromosome 22 with chromosome 9 to form a new chromosome. It appears that the long arm segment of chromosome 22 is translocated to the long arm of chromosome 9, causing the gene BCR (breakpoint cluster region) and ABL to be fused. It can be seen in most CML, some ALL and a few acute myeloid leukemias.
Philadelphia chromosome
discuss
- Chinese name
- Philadelphia chromosome
- nickname
- ph chromosome
- Exist in
- A few acute myeloid leukemias are visible
- Find the time
- 1960
- Philadelphia chromosome refers to the translocation of the long arm of chromosome 22 with chromosome 9 to form a new chromosome. It appears that the long arm segment of chromosome 22 is translocated to the long arm of chromosome 9, causing the gene BCR (breakpoint cluster region) and ABL to be fused. It can be seen in most CML, some ALL and a few acute myeloid leukemias.
- Ph chromosome (Philadelphia 1): Nowell and Hungerford discovered in 1960 that there was a chromosome smaller than the g group in the blood of chronic myelogenous leukemia (cml). Since it was first found in Philadelphia (Philadelphia), it was named ph chromosome. It was initially thought to be caused by the deletion of the long arm of chromosome 22, and it was later proved to be the result of the long arm translocation of chromosome 9 and 22. The translocation recombined the proto-oncogene abl on the long arm of chromosome 9 (9q34) and the bcr (break point cluster region) gene on chromosome 22 (22q11) into a fusion gene. The latter has increased tyrosine kinase activity, and overexpression of the Bcl-Abl fusion gene activates a series of downstream signaling pathways (Jsk-Stat) [1] , which enables cells to initiate proliferation without growth factors, which is chronic Causes of Granulocytic Leukemia. The important clinical significance of ph is that approximately 95% of chronic myelogenous leukemia cases are ph-positive, so it can be used as a basis for diagnosis and can be used to distinguish other blood diseases that are clinically similar but have a negative ph (such as bone marrow). Fibrosis, etc.). Sometimes ph occurs before clinical symptoms, so it can be used for early diagnosis. In addition, patients with chronic myelogenous leukemia who are known to be pH negative respond poorly to treatment and have a poor prognosis.
- In addition, in precursor B-cell and T-cell tumors, namely acute lymphoblastic leukemia / lymphoma, about 3% of children and 25% of adults also detect Philadelphia chromosomes. [2]