Parkinson's does not follow a straightforward skip-a-generation pattern, but genetics do play a role in who develops the disease
Most people with Parkinson's have no family history of it at all. About 10 to 15 percent of those diagnosed have a parent, sibling, or child with Parkinson's. When the disease does run in families, it does not skip generations in a predictable way — some family members get it, others do not, and the age at which symptoms start can vary widely even within the same family.
If you have a parent or sibling with Parkinson's, your own risk is higher than the general population, but it is still relatively low. Having the genetic changes associated with Parkinson's does not mean you will definitely develop the disease. Environmental factors, age, and other unknown influences all play a role in whether someone actually gets sick.
Key Takeaways
- About 10 to 15 percent of people with Parkinson's have a close relative with the disease, but most cases are not inherited.
- Genetic forms of Parkinson's do not follow a skip-a-generation rule — inheritance patterns depend on which gene is involved and how it is passed down.
- Having a genetic mutation linked to Parkinson's does not may provide you will develop symptoms; many people with the mutation never get sick.
- If Parkinson's runs in your family, genetic counseling can help you understand your personal risk and what to watch for.
How Parkinson's is inherited when it runs in families
When Parkinson's is genetic, it usually follows one of two inheritance patterns. Autosomal dominant inheritance means you need only one copy of the mutated gene from one parent to develop the disease. In this pattern, an affected parent has a 50 percent chance of passing it to each child, regardless of the child's sex. This type does not skip generations — if a parent has the mutation, their children are at risk.
Autosomal recessive inheritance requires two copies of the mutated gene, one from each parent. Both parents carry the gene but may not have symptoms themselves. In this case, two carrier parents could have children who develop Parkinson's even though neither parent shows signs of the disease. This pattern can look like it skips a generation because the grandparents carry the gene silently, the middle generation carries it without getting sick, and the grandchildren develop symptoms.
The genes most commonly linked to inherited Parkinson's are LRRK2, SNCA, and GBA. Different genes follow different patterns, and not everyone with a mutation in these genes will get Parkinson's. This is why family history is a risk factor but not a may provide.
Why most Parkinson's cases are not inherited
The majority of Parkinson's cases appear to be sporadic, meaning they develop without a clear genetic cause passed down through the family. These cases likely result from a combination of genetic susceptibility, aging, and environmental exposures — things like pesticide contact, head injury, or other factors that researchers are still working to understand.
Even when someone has a genetic risk factor for Parkinson's, whether they actually develop the disease depends on many things beyond genetics alone. Two siblings with the same genetic mutation may have very different outcomes. One might develop Parkinson's at age 55, another might never get sick, and a third might develop it at 75. This variation is why genetics is only part of the picture.
What to do if Parkinson's runs in your family
If you have a parent, sibling, or child with Parkinson's, you may want to talk with a genetic counselor. A genetic counselor can review your family history, explain what your personal risk might be, and discuss whether genetic testing makes sense for you. They can also help you understand what symptoms to watch for and when to see a neurologist if concerns arise.
Genetic testing is not routine for everyone with a family history of Parkinson's. Testing is most useful if multiple family members have been diagnosed, if someone was diagnosed at a young age (before 50), or if you want concrete information to guide your own health decisions. A neurologist or genetic counselor can advise whether testing is worth considering in your situation.
If you do not have symptoms now, staying physically active, protecting yourself from head injury, and maintaining overall health are steps that may help. Research suggests that exercise in particular may lower the risk of developing Parkinson's, though this is still an active area of study.
Understanding genetic testing and what results mean
If you have genetic testing, a positive result means you carry a mutation linked to Parkinson's — but it does not mean you will definitely get the disease. A negative result means the test did not find one of the known mutations, but it does not rule out Parkinson's risk entirely, since not all genetic causes are yet understood.
Genetic test results can be complicated to interpret, which is why working with a genetic counselor or neurologist is important. They can explain what your specific result means for your health, discuss the chance you might develop symptoms over time, and talk through the emotional weight of knowing you carry a genetic risk.
How age affects Parkinson's risk in families
Parkinson's typically develops later in life, with most diagnoses made after age 60. If you have a family member with Parkinson's, your risk does increase, but it is still possible you will never develop symptoms, especially if you live a long life. Some people with genetic mutations associated with Parkinson's reach old age without ever getting sick.
Age also affects how you might think about genetic testing. A younger person with a family history might choose testing to inform long-term health decisions. An older person might decide that knowing their genetic status would not change how they live their life right now, and choose not to test.
Talking with family members about Parkinson's risk
If you have been diagnosed with Parkinson's or have learned you carry a genetic mutation, you may wonder whether to tell your siblings or children. There is no single right answer — it depends on your family's communication style and what you think would be helpful to them.
Some families find it useful to share information so relatives can make informed decisions about their own health. Others prefer to keep the information private. If you do decide to share, a genetic counselor can help you think through how to have that conversation and what information to include.
Frequently Asked Questions
If my parent has Parkinson's, will I definitely get it?
No. Even if your parent has genetic Parkinson's, you might never develop symptoms. If the disease is inherited through a dominant gene, you have about a 50 percent chance of inheriting the mutation, but inheriting the mutation does not may provide you will get sick. Many people with the genetic change never develop Parkinson's.
Can Parkinson's skip generations?
In recessive inheritance, it can appear to skip a generation because both parents carry the gene without symptoms, and their children develop the disease. In dominant inheritance, it does not skip — affected parents pass it directly to their children. The pattern depends on which gene is involved.
Should I get genetic testing if Parkinson's runs in my family?
That depends on your situation and what you would do with the information. Genetic testing is most useful if multiple family members have Parkinson's, if someone was diagnosed young, or if knowing your status would help you make health decisions. A genetic counselor or neurologist can help you decide whether testing makes sense for you.
What should I watch for if I have a family history of Parkinson's?
Early signs include tremor, stiffness, slowness of movement, balance problems, and changes in handwriting or speech. If you notice these symptoms, see a neurologist for evaluation. Staying active, protecting yourself from head injury, and maintaining overall health are also reasonable steps to take.
Where can I find a genetic counselor?
The National Society of Genetic Counselors has a search tool on their website where you can find counselors in your area. Your neurologist or primary care doctor can also refer you to a genetic counselor. Some counseling is available by phone or video if in-person visits are not convenient.