Loss Of Y Chromosome In Men May Lead To Alzheimer's Disease And Even Death Due To Cancers

Men with blood cells that lack Y chromosome are at a greater risk of developing Alzheimer's disease, as well as dying due to exposure to cancer.

As the loss of the Y chromosome (LOY) is the most "common genetic mutation" that is developed by a person in his lifetime, it affects about 20 percent of men above 80. The team probed the loss in more than 3,200 men between 37 and 96 years.

About 17 percent of the men in the study exhibited LOY in blood cells, a number that increased with age. Moreover, those who showed Alzheimer's disease (AD) diagnosis tended to show a higher degree of LOY, which was connected to a greater likelihood of developing the disease after the study.

"The idea for this research project came to me when I was writing our first paper on the relationship between LOY and the development of non-blood cancers," said Lars Forsberg of Uppsala University and senior author of the study. "In thinking about the process known as immunosurveillance - the body's ability to fight disease development throughout life - I found that it had been well studied in AD, and hence it occurred to me that LOY might be involved in this disease too."

With molecular techniques, Forsberg and his team showed the links between LOY and Alzheimer's disease, along with its links to the risk of death in men with a number of cancers.

However, the mechanisms behind these results are not clear. The team hopes that it can go on to investigate LOY and its effects on various groups of men with other kinds of diseases and their link with early signs of dementia.

Forsberg hopes that the study can integrate LOY tests in diagnosing risks along with other biomarkers.

"The addition of LOY testing in the general population could give medical practitioners the possibility of using preventive strategies in men at risk," he said. "For example, in cancer, primary tumors are usually not deadly; it is the metastatic process that is normally responsible for deaths. If we could predict which men have an increased risk of cancer, we could watch them closely for the development of disease and also use appropriate preventive treatments.

"In short, the widespread use of LOY testing could radically decrease male mortality rates, and even perhaps eliminate the difference in life expectancy between the sexes," he concluded.

The findings were published May 23 in the American Journal of Human Genetics.