Causes of Chronic Myeloid Leukaemia
Causes of chronic myeloid leukaemia are primarily rooted in genetic abnormalities, particularly the formation of the Philadelphia chromosome. While the precise trigger for this mutation is not always known, nearly every case of chronic myeloid leukaemia involves the same genetic change, which has enabled the development of highly targeted treatments.
1. Philadelphia Chromosome and BCR-ABL1 Fusion Gene
The Philadelphia chromosome is a shortened version of chromosome 22 formed when parts of chromosomes 9 and 22 switch places. This results in the BCR-ABL1 fusion gene, which creates an abnormal protein with unregulated tyrosine kinase activity. This protein signals cells to grow and divide uncontrollably, which is the fundamental cause of CML.
This mutation is not inherited; rather, it occurs during a person’s lifetime. It’s an acquired mutation, meaning it happens in the DNA of a single blood-forming cell and is not passed from parent to child.
2. Radiation Exposure | Causes of Chronic Myeloid Leukaemia
Exposure to high levels of radiation has been associated with an increased risk of CML. Studies of atomic bomb survivors and individuals exposed to therapeutic radiation have shown a modest increase in risk. However, CML is rare, even among these groups, and the overall risk remains low.
3. Age and Gender
CML is more common in older adults, with the majority of cases diagnosed in people over 50. Men are slightly more likely to be diagnosed with CML than women, although the reasons for this are not well understood.
4. Environmental and Occupational Exposure
Research has explored the role of chemical exposures such as benzene, but no conclusive links have been established. Smoking, diet, and other lifestyle factors have not been shown to significantly impact CML risk.
5. No Known Hereditary Link | Causes of Chronic Myeloid Leukaemia
CML is not considered a hereditary cancer. There is no consistent evidence that it runs in families or is passed on genetically. Family members of patients with CML are not considered to be at increased risk.
Although the causes of chronic myeloid leukaemia largely centre on a single genetic event, the reasons why this mutation occurs in some individuals and not others remain under investigation. What is known, however, is that this mutation offers a clear therapeutic target, which has revolutionised treatment options and prognosis for CML patients.
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