NEW YORK (GenomeWeb News) – In a paper appearing online last night in PLoS Genetics, researchers from the personal genetics firm 23andMe and the Parkinson's Institute in California reported that they have identified two new loci contributing to Parkinson's disease risk.
The team's web-based genome-wide association study approach involved 3,426 individuals with Parkinson's disease — enrolled over the span of a year-and-a-half through a collaboration between 23andMe, the Michael J. Fox Foundation, the National Parkinson Foundation, and the Parkinson's Institute and Clinical Center — and 29,624 unaffected control individuals who enrolled as customers of 23andMe's personal genome services.
Using custom Illumina HumanHap 550+ arrays to genotype these individuals, researchers not only verified 20 Parkinson's associations identified previously, but also detected two new risk loci — one SNP falling near the lysosomal integral membrane protein type 2 coding gene SCARB2 and another in the vicinity of the SREBF1 and RAI1 genes. Two other variants — in and around the RIT2 gene and the USP25 gene — fell just shy of significantly associating with the disease.
"Not only are these new genetic findings significant, but we've also shown that the data collected by 23andMe support discovery of new associations as well as replication of previously known associations," lead author Chuong Do, a research scientist at 23andMe, said in a statement.
"This study is a rigorous 'proof of principle,'" he added, "and clearly demonstrates that web-based phenotyping works for a disease of real public health significance."
Based on their findings so far, the team estimated that at least a quarter of Parkinson's disease risk can be attributed to genetic factors. Consequently, they say, additional studies are needed to further tease apart the genetic environmental contributors to the disease.
23andMe's Parkinson's disease cohort now consists of more than 5,000 individuals with the condition, the company said. Meanwhile, some 76,000 individuals who use the 23andMe database have reportedly consented to participate in the Parkinson's disease or similar 23andMe research projects.
For instance, the company is currently using a similar web-based approach to study sarcoma, using a cohort that includes more than 500 individuals with that disease.
"We believe this paper proves the potential of our approach of combining genetic information with web-based data about specific conditions to make novel research discoveries," Anne Wojcicki, president and CEO of 23andMe, said in a statement. "This approach has the potential to be used in many other conditions."