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Results from what
could be the largest-ever study of Parkinson's disease genetics in
people of African ancestry found that someone with two copies of a newly
discovered variant are at roughly 3.5 times more risk of developing the
disease than those with no copies. Researchers
at the University of Lagos in Nigeria, the US National Institutes of
Health and University College London probed the genes of 1,488
Parkinson’s patients from Nigeria and the US, and compared them to
DNA from more than 196,000 people who didn’t have the disease. While
the new variant was located in a known Parkinson’s disease risk gene
called GBA1, it hadn’t been seen in previous studies because it’s rare
in European populations, according to the results published in Lancet Neurology. In Black people of African ancestry, it turns out to be relatively common.
Genetic
disease studies have a diversity problem: Historically, they’ve mostly
included people of European ancestry. There are good reasons for
geneticists to study a broader population. Diseases such as Parkinson’s
and Alzheimer’s aren’t well understood and brain pathology and genetics
may vary in people with different ancestries. “Most
of the genetic studies that are done across diseases are done mainly in
people from European populations and that leaves out a whole host of
individuals,” says molecular biologist Ekemini Riley, managing director for Aligning Science Across Parkinson’s (ASAP), which sponsored the study, and, through its Global Parkinson’s Genetics Program,
helped train people in sites in Nigeria that performed it. Studying
diverse populations increases the number of gene variants found and
potentially provides new clues for drug discovery, she says.
You
may not have heard of ASAP, but its a broad initiative funded by
Alphabet co-founder Sergey Brin’s family foundation. Brin, who disclosed
years ago that he has a gene that increases the likelihood of
developing the disease, has quietly become one of the biggest funders of Parkinson’s research. ASAP works hand in hand
with the Michael J. Fox Foundation for Parkinson’s Research to
implement its programs. One of its big projects aims to study the
genetics of Parkinson’s in populations around the world to get a better
picture of what causes the disease. The study in Lancet Neurology is one
of the first big results. Scientists
in Africa have been waiting for the opportunity to do this type of
ambitious project. Most previous Parkinson’s genetics studies in West
Africa have been small scale due to funding and resource constraints,
precluding clear conclusions, says Njideka U. Okubadejo, a neurologist and Parkinson's researcher at the University of Lagos and a senior author on the study. “It
was a dream come true to finally have sustainable support and funding”
to expand the work to a larger network of Nigerian neurologists, she
says. Another important collaborator in the project was the genetics
testing firm 23andMe, which was co-founded by Brin’s former spouse Anne Wojcicki and contributed anonymous data from more than 195,000 people of African American or Afro-Caribbean descent. ASAP’s
Global Parkinson’s Genetics Program is working to support similar
research on almost every continent. “I would expect we’re going to get
many findings like this,” says ASAP’s Riley. — Bob Langreth |