Some genetic risk factors for high cholesterol may not apply to non-European populations, study finds.
Over the last decade, genome-wide association studies (GWAS) have evolved into a powerful tool for genetics research. By scanning whole-genome samples, GWAS can detect genetic variations that contribute to human disease susceptibility. GWAS have been used to identify genetic risk factors for complex diseases that are prevalent in the population including diabetes, cancer, cardiovascular disease, and mental illnesses. While the discovery of disease-relevant genes can lead to new prevention and treatment strategies, these studies are overwhelmingly conducted in those of European ancestry. The fruits of this research may not translate to non-European populations.
A new study published in Nature Communications highlights the issue of racial disparities in genetics research. Researchers at University College London wanted to know whether the genetic variants that affect blood fat levels, a major cardiovascular risk factor, applied to different groups in the UK, Greece, China, Japan, and Uganda. The authors selected these variants from large European ancestry GWAS studies.
“Genome-wide association studies, facilitated by the mapping of the human genome, have transformed our understanding of how our genetics impact our traits, behaviours and disease risks. But the large majority of them have been conducted in people of European descent, so there’s a growing concern that the findings might not uniformly apply to people of diverse backgrounds,” said Karoline Kuchenbaecker, associate professor at the UCL Genetics Institute and lead author of the study.
The authors showed that three-quarters of genetic markers that affect levels of HDL cholesterol, LDL cholesterol and triglycerides were shared between individuals of European ancestry and samples from China, Japan, and Greece. However, only 10% of the genes associated with triglyceride levels were actually implicated in the same cardiovascular risk factors among people from Uganda.
The researchers also constructed a genetic risk score to measure the correlation between known lipid-associated genes and actual fat levels in the serum of the different ancestry groups. The genetic risk score suggested a weak correlation between the identified genes and serum triglyceride levels in samples from Uganda.
“Our findings should serve as a major warning of caution to the field of genetics research – you cannot blindly apply findings from ancestrally European study groups to everyone else,” said Kuchenbaecker.
“We need to ensure that diverse groups are represented in research before proceeding with developing new tests or treatments – otherwise, the consequence will be a very unfair NHS where some new drugs and genetic tests are only suitable for people of European descent.”
Written by Cheryl Xia, HBMSc
- Understanding Society Scientific Group et al. The transferability of lipid loci across African, Asian and European cohorts. Nat Commun 10, 4330 (2019).
- Chris Lane. Some high-cholesterol genes differ between countries. EurekAlert! (2019).
Image by Darwin Laganzon from Pixabay