Importance of diversity in genomics research
21 October 2019
A paper entitled, Genome-wide Association Studies in Ancestrally Diverse Populations: Opportunities, Methods, Pitfalls, and Recommendations, co-authored by Dr Karoline Kuchenbaecker from UGI and Associate Professor, Psychiatry at UCL, has just been published in the Journal Cell.
The Psychiatric Genomics Consortium’s 31 member author group examined the scientific and ethical benefits of including underrepresented groups in genomics research and provides guidance on the strategy for analysing such data. The consortium of scientists is dedicated to conducting analyses of genomic-wide genetic data with a focus on psychiatric disorders.
Dr Karoline Kuchenbaecker commented, ‘The under-representation of non-European groups is problematic for scientific and ethical reasons. The effects of gene variants that are present only in the unstudied groups remain unknown, which means important clues about the causes of diseases might be missed.’
Most participants in genome-wide association studies are of European genetic ancestry, which was a practical starting point when the field of genomic research was young, given available data and tools, the authors write, but this has given rise to striking disparities in representation. The committee reviewed the impact the lack of ancestral diversity can have on genome-wide association studies, which scientists use to search the human genome for common variations that occur more frequently in people with a specific disease than in those without the disease.
‘Thanks to many collaborative efforts, we have now started to build more diverse genomic resources across the world. However, it is still unclear what is the best analytic strategy when samples of diverse population ancestries are available in a study,’ said joint senior author Hailiang Huang, Ph.D., of the Stanley Center for Psychiatric Research at Massachusetts Institute of Technology’s Broad Institute and Harvard University. ‘In this paper we outline key methodological considerations and highlight opportunities, challenges, solutions and areas in need of development, providing a conceptual overview of how to think about and tackle challenging questions in the field.’
With genomics moving into health care and genetic testing growing in popularity, individuals who did not descend from European ancestors may receive false positives or ambiguous results. They are also more likely to get false negatives because of the lack of available research data for their genetic background. As clinical researchers develop precision medicine to fight disease, everyone benefits if genetic risk assessments are based on diverse populations.
Dr Karoline Kuchenbaecker co-authored an opinion piece in The Conversation emphasising the importance of broader participant groups in genetic studies: https://theconversation.com/most-genetic-studies-use-only-white-participants-this-will-lead-to-greater-health-inequality-125150
In addition to the publication in Cell, Dr Kuchenbaecker led a recent paper in Nature Communications.
‘Our recent work also shows that existing genetic findings might not apply equally to non-European populations. We found that some gene variants predicting high cholesterol in "white" populations do not lead to the same heart problems in people from rural Uganda. These findings should serve as a major warning to the field of genetics – one cannot blindly apply findings from ancestrally European groups to everyone else.’ comments Dr Kuchenbaecker.
Ancestry groups in genome-wide association studies (GWAS)
A) Proportion of samples from different ancestry groups in published GWAS based on data from the GWAS Catalogue
B) Population size in millions by continent in 2016
Peterson et al., Genome-wide Association Studies in Ancestrally Diverse Populations: Opportunities,
Methods, Pitfalls, and Recommendations, Cell (10th October 2019) Cell https://doi.org/10.1016/j.cell.2019.08.051
Kuchenbaecker et al., The transferability of lipid loci across African, Asian and European cohorts (24th September 2019) https://doi.org/10.1038/s41467-019-12026-7