A new analysis finds that 78 percent of people represented in human genetic research are of European descent. 10 percent are of Asian descent, while people of African, Hispanic and all other ethnicities make up less than six percent. Unfortunately, it's no surprise that non-European populations are under-represented in biomedical research. But these numbers are striking, and the authors say it is a major impediment to understanding how genes cause disease and how such diseases can be treated.

Sarah Tishkoff is the David and Lyn Silfen Professor in the Department of Genetics and Biology at the University of Pennsylvania. She also serves as a director for the American Society of Human Genetics. When asked whether she was surprised at just how biased the data is she replied, "Well, yes and no." She stated that during the course of her career-spanning research on genomic diversity in Africa, she realized that populations from that region were under-represented in biomedical studies. "There had been a study a few years back," she says, "that showed a biased of people with European ancestry," She says she was shocked that studies in the last several years haven't gotten any better at studying more diverse groups.

Tishkoff continues that one possible reason for the lack of diversity could be because most studies are performed in the US and Europe, and these studies would be conducted on the majority in those regions. Another reason, she states, could be funding and priority by the funding agencies. "If funding agencies were to say, 'This is our top priority; we need to include people of diverse ancestries.', then I think there would be more of a focus on trying to do that," Tishkoff says.

There have also been some biases in past studies, the reason being when you include people of diverse ancestries-in what is called a genome-wide association study-it can be prone to false positive results. And lastly, simply by using people of European descent in studies, you would typically have more participants-than in a diverse study-and this translates to a more powerful study and could ultimately determine if a certain group were to receive grants for future research.

However, diversity in studies is critical to understanding the human genome on a worldwide level, the lack thereof can seriously impair our ability to understand the disease. For example, if there is a disease-causing gene in one population that isn't being studied, that particular gene would simply be missed. Therefore, the gene would go unnoticed and that population would remain at risk. So basically what Tishkoff was saying is that if the research is simpler, have a simpler sample. But on the other hand, science should reflect reality-and the reality is; the human population is diverse.

In short, such lop-sided studies pose a serious health risk to everyone-those included and especially those who are not.