Gene variants associated with blood type may contribute to early stroke risk

Gene variants associated with blood type may contribute to early stroke risk

Gene variants associated with a person's blood type may be linked to their risk of early stroke, according to a new meta-analysis published August 31, 2022, in the online edition of Neurology®, the medical journal of the American Academy of Neurology. The meta-analysis included all available data from genetic studies that included ischemic stroke in young adults, which is caused by a blockage of blood flow to the brain.

Non-O blood types have previously been associated with risk of early stroke, but the results of our meta-analysis showed a stronger association between these blood types with early stroke compared to late stroke and when linking risk primarily to blood type A. In particular, our meta-analysis suggests that gene variants associated with blood types A and O are almost all genetically linked to early stroke Represent gene variants. People with these gene variants may be more likely to develop blood clots, which can lead to strokes.”

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 with stroke and 576,353 people without stroke. Of the patients with stroke, 5,825 people had an early-onset stroke and 9,269 people had a late-onset stroke. Early stroke was defined as an ischemic stroke occurring before the age of 60.

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 contains the gene that determines blood type A, AB, B or O.

They then divided the participants into blood groups A, AB, B and O. They compared the prevalence of these blood types in people with early stroke, late stroke and people who had not had a stroke.

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Researchers found that people with early strokes are more likely to have type A blood and less type O blood, compared to people with late strokes and people without stroke. Both early and late stroke subjects were also more likely to have blood type B compared to controls.

Looking at people of European descent and comparing 5,825 people with early stroke to 29,320 people without stroke, the meta-analysis found that 48% of people with early stroke had type A blood, compared to 45% of people with late stroke and 44% of people without stroke. They also found that 35% of people with early stroke had type O blood, compared to 39% of people with late stroke and 41% of people without stroke.

After controlling for gender and other factors, researchers found that people with blood type A had an 18% higher risk of early stroke than people with other blood types. People with blood type O had a 12% lower risk of stroke than people with other blood types.

“This work deepens our understanding of early-onset stroke development and changes,” said Jennifer Juhl Majersik, MD, MS, of the University of Utah and a Fellow of the American Academy of Neurology, who wrote an editorial accompanying the study. "Future research is needed to develop a more precise understanding of how strokes occur. This could lead to targeted preventive treatments for early-onset strokes, which could lead to less disability in people's most productive years."

A limitation of the study was the limited diversity among participants, although 35% of 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

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.

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