The gene HNF1A critical for the growth and development of the liver and pancreas is linked to an increased risk of stroke in people of African descent, according to new research.
The study, published in Stroke, is the most detailed analysis of genetic determinants of stroke in individuals of African descent in the USA so far.
Dr Bradford Worrall, a neurologist at the University of Virginia in Charlottesville, and co-author of the study said: 'Given the undue burden that people of African ancestry endure from stroke and other cerebrovascular disease, the lack of investigation of risk factors in this group has been a substantial gap.'
Stroke is the second leading cause of death worldwide and a leading cause of long-term disability in the USA. Past research has shown that African Americans have a nearly two-fold increased risk of stroke, more than a two-fold increased risk of fatal stroke, a higher frequency of poststroke disability, and stroke at younger ages compared to European Americans.
The researchers, who belong to the Consortium of Minority Population Genome-Wide Association Studies of Stroke (COMPASS), performed a genome-wide association study (GWAS) on data pooled from 13 cohorts to compare the genomes of 22,051 individuals of African ancestry. Of these, 3734 had experienced ischaemic stroke.
The analysis revealed a mutation near HNF1A. Previous research has reported links between HNF1A variants and an increased risk of stroke, diabetes and coronary artery disease, as well as C-reactive protein levels (which increase in blood in response to inflammation). A further 29 gene variants found at 24 unique chromosome locations were also possible candidates for increased stroke risk. Subsequent analyses using other population genome datasets also found that HNF1A was associated with stroke risk in European populations, with 16 of the 24 locations also having potential associations.
'Our study identified novel associations for stroke that might not otherwise be detected in primarily European cohort studies. Collectively, this highlights the critical nature and importance of genetic studies in a more diverse population with a high stroke burden, such as was the case in this study', wrote the authors.
Unfortunately, the sample size of the study was too small to detect rare genetic variants. The authors also reiterated that stroke is a complex disease with multiple genetic and environmental risk factors. Nevertheless, the study highlights the potential for genetic studies to provide insights into the stroke risk of different populations and support the development of medicines targeted against specific genetic vulnerabilities.
'Our work is an important step toward filling that gap, albeit with much more work to be done. These findings will provide greater insight into ethnic-specific and global risk factors to reduce the second leading cause of death worldwide,' added Dr Worrall.