According to the magazine New Scientist40% of 70-year-old men would end up with immune cells that no longer have a Y chromosome. To better understand the consequences, researchers genetically modified the bone marrow of mice so that approximately two-thirds of their immune cells lose this chromosome.
The results were published in the journal Science and show that cells without a Y chromosome infiltrate the muscle of the heart, causing the secretion of inflammatory molecules. The heart was thus found damaged, a situation likely to cause heart failure.
The scientists also analyzed data from a biobank which contains information on the health of half a million people in the UK. The higher the proportion of immune cells without a Y chromosome in a patient, the higher his risk of dying from heart disease in the next 12 years.
Because it is small and contains few genes, the Y chromosome is not always essential for cell survival, which would explain its frequent disappearance. In addition, certain genetic variations might increase the risk of it disappearing.
