A new study involving over 3,200 people has found that older men with a loss of the Y chromosome in some blood cells may be more likely to develop Alzheimer’s disease. The research is published on Tuesday 24 May in the American Journal of Human Genetics.
The Y chromosome is usually recognised for its role in determining a person’s sex, but previous research has shown that around 15% of men over the age of 70 show some loss of the Y chromosome in more than 10% of their blood cells. Scientists led by a team at Uppsala University in Sweden have also shown that a loss of the Y chromosome in blood cells in later life may also be linked to a higher risk of some cancers. To build on these studies, the same team set out to explore the relationship between loss of Y chromosome and Alzheimer’s risk.
The researchers first looked at data from 1,611 men who were involved in the European Alzheimer’s Disease Initiative in France. Each participant was assessed for Alzheimer’s disease, and had their blood analysed for signs of loss of Y chromosome. In this study, 606 men were diagnosed with Alzheimer’s disease, with the results showing that people in this group tended to have a greater loss of Y chromosome than men without the disease.
The researchers also tested their results by pooling data from two long-running studies in Uppsala, both of which had enrolled groups of older people. Of the 1,599 men involved in these studies, 140 developed Alzheimer’s during the course of the research, over an average of eight years. Analysis of these results showed that men who had some loss of Y chromosomes at the start of the study were more likely to later be diagnosed with Alzheimer’s disease.
The researchers suggest that loss of Y chromosome in blood cells may lead to an increased risk of Alzheimer’s, and argue that testing for this trait could in future help identify older men at risk of developing the disease.
Dr Simon Ridley, Director of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“This interesting study points to a potential new avenue to explore for researchers investigating the development of Alzheimer’s disease. In Alzheimer’s, the first changes in the brain occur many years before symptoms begin to show, and we can’t be certain from this study whether loss of Y chromosome may be part of the chain of events driving the disease or a result of the disease. Further research may allow us to uncover more information about the molecular processes underpinning the disease, an important step in the search for treatments. It’s important to note that not all men with loss of Y chromosome in this study developed Alzheimer’s disease, and these results do not suggest that testing for this trait would be a reliable indicator of Alzheimer’s risk.
“Alzheimer’s disease is the most common cause of dementia, and with no treatments currently able to alter its course, research to understand the disease is vital. If we are to find new treatments and improve the way the disease is diagnosed, we must continue to invest in research.”