The importance of diversity in PD research

Hello everyone,

Recently, I was invited to co-author a review article on the importance of diversity in PD research and, as of now, the manuscript is under review. I thought I’d take a moment to share a few key insights we uncovered during the writing process, as this topic has really stayed with me.

One of the most striking things we found is how much of PD research is still concentrated in high-income countries, both in terms of funding and participant representation. This is despite the fact that nearly half of all people with PD already live in low- and middle-income countries and that number is expected to grow substantially in the coming decades.

We also looked at PD genetics, and the lack of diversity there is even more concerning. Over 90% of participants in GWAS so far have been of European ancestry. This matters because ancestry-specific risk variants are being missed. One example is a GBA1 variant found in 39% of PD cases of African ancestry. This finding required far fewer participants than similar discoveries in European populations.

Environmental exposures are another area where gaps are evident. While many LMICs face increasing exposure to pesticides, air pollution, and industrial chemicals, most environmental PD studies come from the Global North. Finally, the underrepresentation in clinical trials also exist as many individuals simply don’t have access to experimental treatments. In some major PD trials, less than 2% of participants were Black, and many LMICs are not even included in global recruitment efforts.

All of this reinforces what I believe many of us already know: without broader representation, our science remains incomplete. And we need to work towards more inclusivity in PD research!

I Would love to hear if others here have also worked on this topic or are seeing efforts to bridge these gaps in your institutions or countries.

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@danieltds congratulations on getting the manuscript submitted!

In many ways, researchers have been avoidant of investigating non-White populations: 1. they/funders perceive it to be too challenging to recruit participants, 2. it is likely the available reference panels for genotyping and imputation may lack variants exclusive to different ancestral backgrounds (but seems like some things in this space is getting better, e.g. H3Africa Chip - H3ABioNet - Pan African Bioinformatics Network), and 3. the challenge of navigating ancestrally admixed populations - navigating local and global ancestry (Opportunities and challenges of local ancestry in genetic association analyses - ScienceDirect). To had layering to #3 is even in “homogeneous” populations, it seems we need to factor in ancient local and global ancestry as well (original study: Elevated genetic risk for multiple sclerosis emerged in steppe pastoralist populations | Nature, and I wrote a short piece on this wrt MS as part of a debate for a journal that summarizes what we currently know https://journals.sagepub.com/doi/10.1177/13524585241293683).

It is important that we continue to elevate this topic - to discover mechanisms of disease that may be shared or exclusive to various populations. Keep at it :slight_smile:

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Hi Farren,

You raised excellent points on this topic, and I completely agree with you. As you mentioned, there are numerous challenges in studying underrepresented populations, the reason why they remain underrepresented. I believe one of the first steps toward increasing representation is to clearly articulate the reasons behind their underrepresentation and identify the key gaps contributing to it just as you did in your reply.

And thank you for sharing those articles with us in your response!

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excited to see the full review article come out!

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