Research into human genetics is heavily biased towards people with European ancestry, which could lead to big problems later with how the research is interpreted and applied.

The new research and commentary notes that the subjects participating in genome-wide association studies (GWAS) were 78 percent European, 10 percent Asian, 2 percent African, 1 percent Hispanic, and less than 1 percent all other ethnic groups.  That means that the conclusions scientists can draw from the data may be applicable to only people of European descent.  Or it could also mean that limiting the sample base will have dire consequences for people of all ethnicities - Europeans included.

"Leaving entire populations out of human genetic studies is both scientifically damaging and unfair," said researcher Sarah Tishkof, an evolutionary geneticist from the University of Pennsylvania.  "We may be missing genetic variants that play an important role in health and disease across ethnically diverse populations, which may have deleterious consequences in terms of disease prevention and treatment."

A single gene variant plays a role in some diseases, but others are associated with many different genes.  Still others add in environmental factors. This is where a limited body of research becomes a problem.

"The lack of diversity in human genomics studies is likely to exacerbate health inequalities," says another team member, Scott M. Williams from the Case Western Reserve University School of Medicine in Ohio.  "For example, approaches are being developed to predict a person's risk of diseases such as Alzheimer's disease, heart disease, or diabetes based on their status for multiple genes.  But such calculations developed based on evidence from primarily European populations may not apply to people of other ethnic backgrounds."

The answer, say the researchers, is to broaden the GWAS database by using comprehensive biobanks with ethnically diverse individuals that can be linked to extensive health records.

"These initiatives will require the political will to improve funding and infrastructure for studying genomic and phenotypic diversity in global populations," says one more of the authors, Giorgio Sirugo from the University of Pennsylvania.  "The future success of genomic and precision medicine depends on it."