When someone is diagnosed with Parkinson’s disease (PD), one of the first questions that often arises is why? Is this something written in my genes—or could it be related to something I was exposed to in my environment? These questions naturally lead to others: Could my children inherit Parkinson’s disease? Could they be carriers?
In reality, only about 5–10% of Parkinson’s disease cases are genetic. It means that in a small portion of individuals, a mutation in a single gene—known as a monogenic form—can directly cause the disease. In such cases, understanding your genetic background can offer valuable insights and even guide medical and family decisions.
In this blog, we’ll take a closer look at monogenic Parkinson’s disease and, most importantly, what it means to be a carrier.
Parkinson’s disease is a progressive neurological disorder that affects movement, balance, and coordination. In most people, PD arises from a combination of multiple genetic and environmental factors. However, in less than 10% of cases, a single gene mutation is enough to cause the disease — this is what we call monogenic Parkinson’s disease.
Genes Related to Monogenic Parkinson’s Disease
In our previous blog, “Understanding how you Inherit Your Genes”, we explored how genetic traits can be passed through different inheritance patterns—autosomal dominant, autosomal recessive, X-linked, or mitochondrial.
For Parkinson’s disease, the two most common patterns are autosomal dominant and autosomal recessive.
Autosomal Dominant PD Genes
- SNCA (alpha-synuclein)
- LRRK2 (Leucine-rich repeat kinase 2)
- VPS35
Autosomal Recessive PD Genes
- PRKN (PARK2)
- PARK7 (DJ-1)
- PINK1
Other autosomal recessive genes linked with early-onset or atypical forms of Parkinson’s include: PLA2G6, ATP13A2, FBXO7, SYNJ1, DNAJC6, VPS13C, PTPA, and DAGLB.
Knowing which gene is involved is crucial — not only to understand the inheritance risk for your family, but also because genetic diagnosis can help tailor treatment approaches.
Yes, it is possible to pass these genes on to your children. Still, it doesn’t mean they will necessarily develop Parkinson’s disease. The risk depends on whether the condition follows a dominant or recessive inheritance pattern.
A child receives half of their genetic material from each parent, making it crucial to establish whether both parents share the same mutation or if one parent possesses a dominant mutation. This distinction is significant because it influences the likelihood of genetic disorders in the child.
Therefore, understanding carrier status is essential, as is discerning whether the inheritance pattern is dominant or recessive.
What Is a Parkinson’s Disease Carrier?
A carrier is someone who carries one mutated copy of a Parkinson -related gene but does not show symptoms of the disease. However, they can still pass this mutation on to their children.
If you’d like to learn more about how inheritance probabilities work, visit our blog “Understanding How You Inherit Your Genes.”
Dominant vs. Recessive: What’s the Difference?
Autosomal dominant genes (e.g., LRRK2) mean that even one copy of the mutation can increase your risk. However, it doesn’t guarantee you’ll develop Parkinson’s. In these cases, there are no true “carriers,” since one copy may already have an effect.
Autosomal recessive genes (e.g., PARK2 or PINK1) require both copies of the gene to be mutated for the disease to appear. People who have only one copy of the mutation are carriers and typically do not experience symptoms.
The only way to confirm whether you are a carrier or have a monogenic Parkinson’s disease mutation is through genetic testing.
Genetic testing can be highly informative but should always be guided by a qualified healthcare professional—such as a neurologist or a genetic counselor. These specialists can help interpret your results and explain what they mean for you and your family.
You might consider genetic testing if:
- You have symptoms that suggest a possible genetic cause.
- You or a family member developed Parkinson’s disease before age 50.
- You have a strong family history of Parkinson’s disease.
- You or your partner have a family history of monogenic Parkinson’s disease and are considering family planning.
Consulting with healthcare providers and genetic counselors ensures that test results are accurately interpreted and effectively integrated into your medical care.
Let’s say your grandparent had monogenic Parkinson’s disease and your test results show that you carry a LRRK2 mutation. What does that mean for you?
Having a mutation does not automatically mean you will develop Parkinson’s disease. Many people carry mutations linked to various conditions yet never develop symptoms. If your mutation is in a dominant gene like LRRK2, your risk may be higher—but still not guaranteed. Suppose it’s in a recessive gene like PARK2 or PINK1. In that case, you’re unlikely to develop Parkinson’s yourself, though your children may be at risk if your partner is also a carrier.
While most cases of Parkinson’s disease are not inherited, understanding your genetic makeup can provide powerful insights into your health and your family’s future.
Remember: genetic knowledge is not something to fear—it’s a tool that empowers you to take proactive steps toward understanding and managing your health.
References
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