Genetic variants associated with a person’s blood type may be linked to their risk of early stroke, according to a new meta-analysis published in the Aug. 31, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology. The meta-analysis included all available data from genetic studies that included young adult ischemic stroke, which is caused by a blockage of blood flow to the brain.
Non-O blood types have previously been linked to an early stroke risk, but the results of our meta-analysis showed a stronger link between these blood types and early stroke compared to late stroke, and by relating risk primarily to blood type A. Specifically, our meta-analysis suggests that gene variants linked to blood groups A and O account for nearly all of those genetically linked to early stroke. People with these genetic variants may be more likely to develop blood clots, which can lead to stroke.”
Braxton D. Mitchell, PhD, MPH, study author, University of Maryland School of Medicine in Baltimore
The meta-analysis included a review of 48 studies on genetics and ischemic stroke from North America, Europe and Asia. The studies included 16,927 people who had a stroke and 576,353 people who did not have a stroke. Of the people with stroke, 5,825 people had an early-onset stroke and 9,269 people had a late-onset stroke. Early-onset stroke was defined as ischemic stroke occurring before the age of 60, and late-onset stroke was defined as more than 60 years of age.
The researchers examined all chromosomes to identify genetic variants associated with stroke. They found a link between early stroke and the area of the chromosome that includes the gene that determines blood type A, AB, B or O.
They then divided the participants into blood types A, AB, B and O. They compared the prevalence of these blood types in people with early stroke, late stroke and people who did not have a stroke.
The researchers found that people with early stroke were more likely to have blood type A and less likely to have blood type O compared to people with late stroke and people without stroke. Both early and late stroke were also more likely to have blood type B compared to controls.
When looking at people of European descent and comparing 5,825 people with an early stroke to 29,320 people who did not have a stroke, the meta-analysis found that 48% of people with an early stroke had blood type A in compared to 45% of people with a late stroke. and 44% of people without stroke. They also found that 35% of people with early stroke had blood type O compared with 39% of people with late stroke and 41% of people without stroke.
After adjusting for gender and other factors, the researchers found that those with blood type A had an 18% greater risk of early stroke than people with other blood types. Those with blood type O had a 12% lower risk of stroke than people with other blood types.
“This work deepens our understanding of the development and changes of early-onset stroke,” said Jennifer Juhl Majersik, MD, MS, of the University of Utah and a fellow of the American Academy of Neurology, who write an editorial that accompanies the study. “Future research is needed to help develop a more precise understanding of how stroke develops. This could lead to specific preventive treatments for early-onset stroke, which could lead to less disability during the most productive years of life.” people”.
A limitation of the study was the limited amount of diversity among the participants, although 35% of the participants were of non-European descent.
The study was supported by the National Institutes of Health and the Department of Veterans Affairs.
Source:
American Academy of Neurology
Journal reference:
Jaworek, T., et al. (2022) Contribution of common genetic variants to the risk of early-onset ischemic stroke. neurology doi.org/10.1212/WNL.0000000000201006.