Genetics account for around 10% of Parkinson’s cases.

Genes can increase the risk of developing Parkinson’s, but having a mutation does not guarantee that you or your children will develop Parkinson’s.

How much do genes play a role in Parkinson’s?

Genes such as SNCA, PARK2, PINK1, and LRRK2 can increase the risk of developing Parkinson’s, but they account for only 10-15% of all cases. It’s important to remember that having these genetic mutations does not guarantee that you or your children will develop Parkinson’s (i.e. about 90% of cases are not directly inherited). The collective influence of genes, environment, and lifestyle determines the likelihood of developing the condition, giving you some control over your health.

The role of genes in Parkinson’s

Genes play a significant role in Parkinson’s, influencing both the risk of developing the condition and its progression. Genetic mutations or variants in specific genes can increase the likelihood of developing PD, although most people with PD do not have a known genetic link.

Genetic risk refers to the likelihood of developing a disease based on one’s genetic makeup. In Parkinson’s, certain genetic mutations can increase the risk of developing the disease. These mutations can be inherited from parents or occur spontaneously. Understanding genetic risk helps researchers develop targeted treatments and personalised medicine strategies. If you are diagnosed with a genetic mutation in relation to Parkinson’s it is highly recommended to get genetic counselling to understand what this means for you and your relations.

The risk of passing Parkinson’s to children depends on the specific genetic mutations involved. If a parent has a genetic mutation linked to Parkinson’s, there is a chance their children may inherit it. However, most cases are due to a complex interplay of genetic and environmental factors, so having a genetic mutation does not guarantee that someone will develop the condition.

Factors contributing to genetic mutations

Several factors can contribute to genetic mutations, including:

  • Inherited genetic mutations that are passed down from parents.
  • Spontaneous mutations can occur randomly in the DNA.
  • Environmental factors like exposure to toxins, pesticides, and other environmental factors can increase the risk of genetic mutations.
  • Young-onset Parkinson’s disease (YOPD) typically occurs before the age of 50 and is often linked to specific genetic mutations. The most common genes associated with YOPD include PRKN, PINK1, and SNCA. (1)
  • Approximately 10–15% of people with Parkinson’s disease have a genetic link, involving mutations in genes such as LRRK2, GBA, and SNCA.
  • A large-scale genetic study identified 78 independent loci associated with Parkinson’s risk, including 12 previously unknown genetic regions (National Institute on Aging, 2024).
  • In the PD GENEration study, 13% of participants with Parkinson’s were found to carry a genetic mutation, with GBA1 mutations present in 7.7%, LRRK2 in 2.4%, and PRKN in 2.1% of cases (Parkinson’s Foundation, 2024).

How do I access genetic testing in Australia?

In Australia, there are several options for genetic testing for Parkinson’s:

  1. Australian Parkinson’s Genetics Study (APGS) run by the QIMR Berghofer Medical Research Institute in Brisbane, aims to identify genetic factors influencing the risk of developing Parkinson’s disease. Participants can complete an online questionnaire and donate a saliva sample from home.
  2. Shake It Up Australia Foundation supports research into Parkinson’s disease, including genetic studies. They often collaborate with other research institutions to provide genetic testing and participate in studies like the APGS.
  3. Some specialist neurology clinics and hospitals in Australia may offer genetic testing as part of their diagnostic services. It’s best to consult with your neurologist or GP to get a referral to a specialist who can provide this testing.
  4. Occasionally, research studies and clinical trials may offer genetic testing as part of their recruitment process. Keep an eye on announcements from research institutions and foundations.

If you’re interested in participating in genetic testing, it’s a good idea to discuss it with your healthcare provider, who can guide you on the best options available based on your specific situation.

Known genetic mutations and their roles in disease risk

Here are some of the known genetic mutations associated with Parkinson’s disease and their roles in disease risk:

Gene Role in Disease Risk
SNCA Produces alpha-synuclein protein, which forms Lewy bodies in brain cells. Mutations can cause early-onset PD.
PRKN Produces parkin protein, involved in protein degradation. Mutations are a common cause of YOPD.
PINK1 Produces a kinase that protects mitochondria. Mutations can cause YOPD.
LRRK2 Produces a kinase involved in cell signaling. Mutations are linked to late-onset PD.
GBA Produces glucocerebrosidase enzyme. Mutations are the most common genetic cause of PD.
PARK7 Produces DJ-1 protein, which protects against mitochondrial stress. Mutations can cause YOPD.
VPS35 Involved in vesicle trafficking. Mutations are a newly identified cause of PD.

Infosheet under review

References:

(1) Gupta, Parul, Neha Jain, and S. K. Meena. “Enhancing Quality of Life in Parkinson’s Disease: A Systematic Review of Occupational Therapy Interventions on Balance and Reaction Time.” Journal of Complementary and Alternative Medical Research 23, no. 4 (2023): 24-32.

(2) Sturkenboom, I. H., M. J. Graff, J. C. Hendriks, Y. Veenhuizen, M. Munneke, and B. R. Bloem. “Occupational Therapy for Patients with Parkinson’s Disease.” 50 Studies Every Occupational Therapist Should Know (2023): 59.

(3) ParkinsonNet Occupational therapy guidelines www.parkinsonnet.com/guidelines