New Study Emphasizes Critical Need for Diversity of Research Participants in Genetic Studies

By Karina Antenucci

Studies of whites dominate the research literature to date despite being one of the smallest populations worldwide. A new paper in Nature presents evidence that the field of human genetics must improve the diversity of research participants to avoid worsening existing health inequities among different racial and ethnic groups, particularly where heart disease is concerned.

Blood cholesterol levels (also called lipid levels) are both highly genetic and a highly treatable health trait, and serve as a primary risk factor for heart disease, the leading cause of death worldwide. However, most previous genome-wide association studies, a study design used to detect associations between genetic variants and common diseases or traits in a population, have been conducted in European ancestry populations. Therefore, they may have missed genetic variants contributing to lipid level variation in other ancestry groups. 

The Nature article is a large collaboration with hundreds of coauthors from over 200 studies in 44 countries. It takes a look at the blood cholesterol levels of around 350,000 participants with Hispanic, African, East Asian, or South Asian ancestry, in addition to 1.3 million participants with European ancestry.

The paper’s key findings include:

• Most genetic variations that influence lipid levels are observed across all populations, but at least some variants are uniquely observed in one population, particularly among individuals with African ancestry or Hispanics.
• The ability to pinpoint the genetic variants most likely responsible for biological effects and to predict lifelong LDL cholesterol (“the bad cholesterol”) levels using genetic risk scores improves significantly when the initial genetic study includes diverse ancestries.
• There is a need not only for future larger genetic studies of lipid levels but also for studies that prioritize the enrollment of individuals from diverse ancestries to improve genetic studies of health traits and diseases, such as cardiovascular disease.

“A sensible and equitable approach is to ensure diverse ancestries are represented in genetic studies whenever possible. Diversity helps to determine the degree to which findings can be generalized to other health traits and diseases,” says Yan Sun, PhD, associate professor of epidemiology, who is co-senior author on the paper.