Genetics, and the role of genes in disease development, has become a major focus for many Parkinson's disease researchers. Although only about 15 percent of Parkinson's patients have a family history, most cases of the disease involve interactions between genetic and environmental factors.

Genetic Mutations

There are two categories of genetic mutations. Causal mutations actually cause the disease. They are rare and account for only 1 to 2 percent of cases. Associated genes don't directly cause Parkinson's disease, but increase an individual's risk (susceptibility) for developing the disease. Some people who have associated genes never develop Parkinson's, while others without these genes do.

To date, Parkinson's researchers have identified about 13 mutations associated with Parkinson's disease. Of these, they've linked five to family history. Although experts are not yet clear how genetic changes cause or influence the disease, they've identified a number of possible reasons for the link.

Genetic Testing

Scientists are developing genetic tests to see who is at risk for Parkinson's disease. Understanding risk factors will help physicians diagnose the disease early. It will also facilitate research into treatments that may be curative and do more than just treat symptoms, as current treatments do.

Currently, genetic testing for individuals is controversial. Because the medical community does not yet have treatments to slow the development and progression of Parkinson's, genetic testing is generally limited to research and is not part of routine clinical practice. Furthermore, families should undergo counseling following genetic testing for Parkinson's disease, so family members can make appropriate decisions if they learn they are at increased risk.

However, at-home genetic testing has become widespread and individuals can order a Personal Genome Service from several online sources. For example, if you send a small sample of cells swiped from the inside of your cheek, they will analyze the sample and send you a report about your own DNA and any genetic variants you may have.

Contributing to Research uses social media to collect genes from thousands of people to search for genes linked to Parkinson's (and other diseases). Researchers believe so many genes are ultimately involved with Parkinson's that the effect is too minute to detect in small samples.

According to an interview on NPR, skeptics question whether customers truly represent the population and if subjects can be trusted to accurately report their diagnoses and symptoms. Regardless of doubters, says it has discovered two genes and uncovered a previously unknown rare combination of mutations associated with Parkinson's disease.



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Parkinson's Disease Information. "Parkinson's Disease Genetic Influence." Web.

Genetics Home Reference. "What is Parkinson disease?" Web. May 2012.

Pankratz, Nathan D., PhD, Wojcieszek, Joanne, MD, and Foroud, Tatiane, PhD. "Parkinson Disease Overview." National Center for Biotechnology Information. Web. 9 July 2009. Web.

Gwinn, Katrina, M.D. "Genetics and Parkinson's Disease: What Have We Learned?" Parkinson's Disease foundation. Web. Winter 2009.

Cuda-Kroen, Gretchen. "Search For Parkinson's Genes Turns To Online Social Networking." NPR blog. Web. 20 August 2012.