Genetics & Parkinson's

We do not know exactly what causes Parkinson's disease (PD), but scientists believe that a combination of genetic and environmental factors play a role in determining if, and when, a person may develop PD. The extent to which each factor is involved varies from person to person.

Parkinson’s Foundation research has found that approximately 13% of people with Parkinson’s have a genetic link to the disease. In some families, changes in the DNA code of certain genes (known as genetic mutations or variants) are inherited or passed down from generation to generation. Some ethnic groups more commonly carry variants in genes linked to PD — researchers are still trying to understand why.

Regardless of how a person gets Parkinson's — through genetics or environment or a combination of both — every person with PD experiences a loss of dopamine in the brain, along with symptoms and a progression of their disease that is unique to them.

Parkinson's Genes

Over the years, scientists have studied DNA from people with Parkinson's, looking for changes in their genes. They have discovered dozens of genes with changes linked to Parkinson's. These genes are being studied for what role they play in Parkinson's.

The underlying genetics, symptoms and prognosis of PD is complex. There are many variants within many genes that may be associated with Parkinson’s. Some gene variants are more common than others among people with PD.

However, most people with PD do not have a genetic link to the disease.

What if I carry a variant in a gene related to Parkinson’s?

Ongoing clinical trials are testing new treatments for people with Parkinson's who carry specific gene variants. Knowing whether someone has a gene variant, and which one, can be important for accessing these trials testing potential therapies. Talk to your doctor when considering a genetic test to determine if you are eligible to participate in gene-based clinical trials.

The Parkinson’s Foundation study, PD GENEration: Mapping the Future of Parkinson’s Disease, is the first global study to offer genetic testing and counseling at no cost for those with a confirmed Parkinson’s diagnosis. If you are interested in empowering yourself and your care team with information about the potential contributions of genetics to your PD, learn more and enroll.

If I have Parkinson's will my child get it too? Will I inherit Parkinson's if my parent or grandparent has it?

Like many other diseases, Parkinson's is a result of a complex interaction between genes and environmental factors. Most people with Parkinson's (almost 90%) have no known genetic variant contributing to their PD. This means it is unlikely they will “pass on” a genetic risk for Parkinson’s to their children through their DNA. 

Family members of those with PD have an increased risk of developing Parkinson’s — about a 2% chance versus a 1% chance for those without a relative with PD. It is possible that the increased risk is from sharing similar environmental exposures to the family member with Parkinson’s. It is also possible that there remain genetic links for scientists to uncover.

In a small number of people with PD (around 10%), Parkinson's is caused by an inherited genetic variant and can affect multiple family members. Their children may have a higher risk of developing Parkinson's if they inherit the genetic variant. However, there is still no guarantee they will develop PD. Many people with these variations do not get PD.

For example, a person may inherit a genetic variant that increases their risk for Parkinson's, but they may also inherit variants in other genes, be exposed to environmental factors or have lifestyle choices that offset the risk. This quest to understand the complex genetics of PD is a driver behind the PD GENEration study. 

Learn more about how genetic variants can be inherited

Should I take an at-home genetics test to see if I will get Parkinson's?

Genetic tests are not a substitute for a diagnosis. Always consult with a genetic counselor before and after taking a genetic test. Most at-home genetic tests check for a limited number of genetic variants linked to PD and can be misleading. It is possible that those who test negative may still develop Parkinson's, as the tests are incomplete and other PD-associated genes have yet to be discovered.

PD GENEration is a research study that offers genetic testing for Parkinson’s and is provided ― along with genetic counseling ― at no cost to people with a PD diagnosis. People with PD can participate in-person at one of our PD GENEration sites or from home. Learn more and enroll.

Am I more likely to get Parkinson's because of my genes or environment?

Parkinson's in most people is thought to be a complex interaction between environmental factors and genetics. A person who is genetically pre-disposed to Parkinson's might be exposed to certain environmental factors (pesticides and herbicides) and have lifestyle choices (exercise, smoking, caffeine) that can influence the risk for developing Parkinson's.

 Typically, in most people with Parkinson's, it is difficult to unravel and separate the environmental influences from the genetic components. In rare instances when multiple family members have Parkinson's, variants in certain genes are inherited that are more likely to contribute to developing PD.

Should I see a genetic counselor if a family member has Parkinson's?

If Parkinson's runs in your family and you want to get genetically tested, consult with a genetic counselor first, if possible, or with the doctor guiding your care. Genetic testing may help estimate the risk of developing Parkinson's but is not a diagnosis and cannot provide an exact probability of developing the disease.

A genetic counselor is a specialist on a healthcare team who provides risk assessments and education about genetics and how to read test results. Call the Parkinson's Foundation Helpline 1-800-4PD-INFO (1-800-473-4636) for help finding a genetic counselor.

There are commercial companies that offer genetic testing for Parkinson's, but these tests often don’t include genetic counselling unless separately coordinated through your clinical care team. However, the Parkinson’s Foundation PD GENEration study offers free genetic testing and counseling to people with a PD diagnosis.

How can genetic test results help me?

Talk to your doctor about genetic testing in Parkinson's and speak to a genetic counselor before and after taking a genetic test. Knowing your genetic risk of PD can provide a sense of empowerment and control and may lead to better treatment and care.

Finding out if you carry a genetic variant may also help you determine if you are eligible to enroll in certain clinical trials. For example, ongoing clinical trials are already testing treatments for people who carry certain PD gene variants in LRRK2 and GBA. These treatments specifically target the cell processes in your tissues that are interrupted by variants in these genes.

For many people with Parkinson's, genetic tests are difficult to access because they may be unaffordable, not covered by health insurance, or not offered with genetic counseling. Studies like PD GENEration offer free genetic testing for GBA and LRRK2, among other PD genes as well as free genetic counseling.

What research is being done on genetics and Parkinson's?

Genetics can be a powerful tool used to help us understand what is responsible for causing, slowing or stopping the progression of Parkinson's — ultimately helping us improve care and speed the development of new treatments.

The Parkinson's Foundation PD GENEration study is working to accelerate PD research and care as we track the genetic makeup of more than 20,000 people with Parkinson's in the U.S. and across the world.