The absence of diversity in genetic datasets

Faridah Giwa
Faridah Giwa
November 19, 2020, 4 mins read
The absence of diversity in genetic datasets

“Diversity issues aren’t just moral, but also scientific.”Alicia Martin, Geneticist, Broad Institute of MIT and Harvard. 

In 2003, the Human Genome Project was completed, and the world celebrated this monumental win for science and the human race. No longer would man be powerless to the cruel and unyielding arms of disease. Instead, the completed human genome model would be used to pinpoint areas of genetic flaws and defects in people with particular diseases. Few years after the project’s completion, various studies began to discover novel genetic regions and variants in people of non-European origin, sparking a world-wide conversation of the need for diversity in genomic studies.

Among one of the most largely excluded participants of genomic research is the African population, constituting less than 3% of Genome-wide Association Studies (GWAS) by 2018. This partial omission has resulted in the creation of disproportionately large datasets based predominantly on European-focused findings, while the data dearth of African populations deepen.

According to a commentary published in the journal Cell, 78% of data used in Genome-wide Association Studies (GWAS) come from people of predominantly European descent, even though they make up only 16% of the global population. 

As stated by Sarah Tishkoff, University of Pennsylvania Genetics and biology Professor, and her colleagues in the same commentary, the absence of racial and ethnic diversity in genomic research impedes the accurate translation of genomic findings into clinical practice and health policies, and may lead to costly misinterpretations as most populations have their own unique genomic profiles not yet taken into account by researchers.

Underrepresented demographics missing from genomic databases bear the brunt of additional challenges during diagnosis while attempting to properly identify genetic variants responsible for a disease’s symptoms. Neil Risch, a Human geneticist at the University of California, in an article by The Scientist claims that identifying any genetic links to symptoms expressed by these demographics is rather difficult due to the manifested disease most likely to be caused by novel variants yet to be identified as pathogenic.

Exclusion in genomics studies hardly stops at being a squandered opportunity for better understanding the human genome, but is also an endangerment to the health of these underrepresented demographics. For instance, doctors have known for years that people of African, Puerto Rican, and Mexican descent suffer unusually high rates of asthma-related deaths, but only recently learned these groups were found to carry genetic variants most likely responsible for their reduced sensitivity to Albuterol (a medication used in inhalers). This deduction could have easily been made much earlier if there were larger and more diverse pools of genomic data on lung diseases. However, 90% of such research has focused mostly on populations of European descent with little to no information on others. Discrepancies like this are not only limited to lung diseases, but many other conditions.

Generally, including African ancestry in genomics research helps in improving the understanding of health disparities. Despite the fact that social and economic factors are the most critical contributors to health disparities, genomic research can possibly help unwind disparities in health outcomes that are improperly credited or attributed to race. 

It is a known fact that modern humans originated from a common ancestor in Africa, and the migration of various sub-populations led to changes in their genetic makeup, which eventually became solidified by their distinct settlement environments. But the genetic diversity in Africa still remains the greatest in the world, and accurate mapping and identification of new disease loci can be confounded if African genetic diversity is not fully understood. 

The only chance at amending these genomic research oversights and broadening the scope of focus is by collecting new samples from previously overlooked populations. In Africa, several of such initiatives like research projects undertaken by 54gene, hope to bridge this data gap from the African perspective.

As a health technology company, 54gene is conducting research into the study of prevalent diseases and delivering precision medicine to the continent and across the world, by leveraging state of the art equipment, novel methods and techniques. By incorporating diversity into genomic data, a plethora of opportunities open up to understand new genes underlying diseases or even new therapeutics from insights into genomes never before traversed by science.

Source materials

Lack of Diversity in Genetic Datasets is Risky for Treating Disease

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Lack of diversity in genetic research could be costing us our health

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The Missing Diversity in Human Genetic Studies

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