Shivangi Sinha • 2021 Science Communication Series Cohort
Source: Shivangi Sinha, Canva
As of 2021, less than 2% of analyzed human genomes are from people of African descent. With genetic testing technology growing more accessible by the minute, this should be especially alarming since Africa contains more genetic diversity than any other continent . The overrepresentation of European-derived genetics erases the value of genetic variety flowing within Africa and other parts of the world. Working with a European-skewed genetics database when it comes to research is harmful to all people because it inaccurately translates into healthcare practices and clinical research and development. This endangers all of society, so there needs to be a push towards accurately accounting for the ethnic diversity naturally present.
With the staggering amount of progress made within the past few decades in genetics research, it should be astonishing how limited the genomic data we have collected so far is. Whole genome sequencing is when the genome of a single cell is analyzed and allows for a very comprehensive look into someone’s DNA. In 2020, whole-genome sequence analyses of just 426 people across 50 ethnolinguistic groups in Africa revealed more than 3 million genetic variants that were previously unknown . That’s right - 3 million! Nevertheless, it is estimated that around 78% of genome-wide association studies (GWAS)—which help identify genetic variants associated with complex traits in disease—come from individuals of European ancestry. Keep in mind individuals of European ancestry only comprise around 16% of the global population .
These statistics only encompass some of the identified issues within genetics research. Genomic research can help unravel the genetic connections with existing health disparities, as is the case with kidney disease, which historically occurs at a much higher rate in individuals of African ancestry . For example, studied differences in kidney transplant outcomes that had once been attributed to racial identity were found to be better described by previously unidentified genetic variants and the relative increased risk of kidney disease with these variants . Considering how little genomes of African descent have been researched, it is unreasonable to assume the data we have collected so far is universally applicable to people of various ethnic groups.
You may be asking yourself, “how does it affect me?” For one, using broad strokes across all ethnic backgrounds when looking at data predominantly collected from one group spreads a lot of generalizations among scientists, healthcare professionals, and patients. One 2016 study noted that a genetic test had inaccurately claimed that several patients with African ancestry had a high risk of, at one point, developing heart disease based on their results. The test itself had been devised using data groups stemming from primarily white, European ancestry populations. Variants identified within the patients of African ancestry, once deemed as exemplifying high-risk for heart disease, turned out to be nothing of importance . Testaments such as this highlight the importance of inclusive, ethnically diverse genetic testing and research. The emotional, psychological, and physical tolls of receiving critical healthcare news, then being told it was actually false, creates an environment of scientific skepticism and distrust. Ethnic diversity in genomic research can provide the required databases and direction for healthcare providers. This helps a variety of healthcare professionals in making more suitable, scientifically accurate decisions for patients of diverse ancestry .
Furthermore, accurate genetic databases are incredibly important for the future of personalized/precision medicine we hear of so often in the media. Personalized or precision medicine is the use of one’s unique genetic “fingerprint” to tailor medical treatments towards individuals, rather than groups. Now, remember the GWAS mentioned earlier? They’re actually super important! They are the grounds for studies in drug development and even clinical guidelines . Highlighting the fact that 78% of GWAS come from individuals of European ancestry, this bias might represent one of the biggest obstacles to the universality of precision medicine . This hinders the overall development of clinical research within precision medicine and diminishes the effectiveness of personalized medicine to ethnically diverse populations.
In recent years, scientific institutions have had a heightened awareness of these disparities and have made an active effort to reduce these existing differences. Various initiatives, such as the Human Heredity and Health in Africa Initiative (H3Africa) and the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), are carving the path to have ethnically diverse genetic databases with these underrepresented populations [1, 5]. It is our responsibility to hold scientific institutions accountable in their pursuit of diversifying genetic databases and ensure the importance of ethnically diverse populations in research is understood at all levels of scientific education. Biases start early, so ensuring students are educated on the benefits of diverse genomic data is a jumpstart to increasing the inclusiveness within genetics research further on.
Wonkam, A. (2021, February 10). Sequence Three Million Genomes Across Africa. Nature News. https://www.nature.com/articles/d41586-021-00313-7.
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Bentley, A. R., Callier, S. L., & Rotimi, C. N. (2020). Evaluating the promise of inclusion of African ancestry populations in genomics. NPJ genomic medicine, 5(1), 5. https://doi.org/10.1038/s41525-019-0111-x