is leukemia hereditary | 7 Questions about chronic myeloid leukemia

7 Questions about chronic myeloid leukemia

The World Day of awareness of chronic myeloid leukemia, September 22nd, is an opportunity to revisit this rare and unsung disease.


1. What is "chronic myeloid leukemia"?
Chronic myeloid leukemia (CML)  "is characterized by excessive and persistent production in the bone marrow of white blood cells," explains the French Hematology Society (SFH). Some of these white blood cells are abnormal because their development is not complete (we are talking about "immature" cells) when they pass through the bloodstream.

2. What is the origin of this disease?
The disease is related to the appearance of an anomaly due to the fusion of two chromosomes (9 and 22) of the bone marrow stem cells, causing the appearance of a small abnormal chromosome, the Philadelphia chromosome (the name of the city where the Two researchers who discovered it in the years 60). The presence of the chromosome induces the production of a gene (named "BCR-ABL ") that codes for the synthesis of an enzyme (tyrosine kinase). But this enzyme is responsible for the production of white blood cells. Synthesized in excess, it produces too many white blood cells.

Myeloid. Leukemia refers to a blood disease, which is characterized by a significant increase in the number of white blood cells. The term "myeloid" refers to the bone marrow, tissue contained in the bones where all the cells of the blood are produced. We are talking about chronic disease when it gradually settles down and evolves slowly at first.

3. Is it hereditary?
 "The Philadelphia chromosome is a genetic anomaly acquired by abnormal stem cells; It is therefore not hereditary  ", specifies the SFH. The causes of its appearance are hitherto unknown. However, there was a greater frequency of CML among the survivors of the atomic bombings of Hiroshima and Nagasaki. Ionizing radiation has therefore been suspected of being able to cause the disease, but this has never been formally demonstrated.

4. What are the symptoms?
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CML evolves slowly at first and does not result in any particular symptom, apart from the more often moderate fatigue and an increase in the size of the spleen. It is thus usually discovered in a fortuitous way, on the occasion of a blood check which shows an elevation of the number of white blood cells.

5. What frequency in the population?
CML is a relatively rare disease, since there are about 600 new cases per year in France, according to the SFH. It occurs more in humans than in women and its frequency increases over time: The median age of patients at the time of diagnosis is 53 years.

6. How is the diagnosis established?
The diagnosis is based on several examinations, including bone marrow removal (myelogram) and blood tests to detect the BCR-ABL gene.

7. What are the treatments?
Treatments, to be taken on an ongoing basis, are based on the administration of medications that prevent the enzyme tyrosine kinase from functioning (these are the "tyrosine kinase inhibitors"). The number of white blood cells decreases and becomes normal again.  "These treatments are usually associated with a good therapeutic response," says SFH. Treated people lead an almost normal life.  "In September 2015, a team of French researchers and doctors published in the journal Nature A study showing that it is possible to destroy tumor stem cells, resistant to treatment Anti-cancer, chronic myeloid leukemia of the elderly.