Genetics and Parkinson’s: ask the expert
The genetics of Parkinson’s is complex and can be confusing. But does that mean people should worry about passing the condition on to their children or consider genetic testing?
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In the second blog of this series, we’re joined by Professor Huw Morris, an international expert in Parkinson’s and it’s genetics, who answers some of the most frequently asked questions on this complex topic.
Q. How concerned should I be if Parkinson’s runs in my family?
Parkinson’s is a relatively common condition, so it’s fairly common for people with Parkinson’s to have one other member of their family who is also affected by the condition.
If your family looks like image 1 (below) the likelihood of you carrying one of the gene variants we currently know cause inherited Parkinson’s is still low — around 1 in 50.
It’s less common for Parkinson’s to affect several members of the same family and this would increase the chance of having a single gene cause.
But even if your family looks like image 2 (below) you still only have around a 1 in 10 chance of carrying one of the known genetic variants. There are likely to be more genetic changes for Parkinson’s that have not yet been identified, so this may change over the coming years.
Q. Is genetic testing available on the NHS?
Yes, genetic testing is available but the directly inherited genetic forms of Parkinson’s are very rare and there are currently no treatments that can prevent the condition. We would usually consider genetic testing for people who develop the condition early (before the age of 40) or who have a strong family history, with several people in the family affected.
If you are considering genetic testing it’s important that you fully understand what it means before it’s carried out.
Some people may find it helpful to talk to a genetics specialist (a doctor or a counsellor) before proceeding with genetic testing. We would recommend that all patients and or families with a positive genetic test have access to genetic counselling to help them understand the possible implications.
Q. Why is genetic research so important?
The reason I’m so passionate about genetics is that I believe that understanding the genetic variants involved in Parkinson’s will lead us directly to new treatments.
Many of the variations we’ve identified are involved in key processes and activities inside brain cells and have helped us understand more about what goes wrong with them in Parkinson’s. Crucially, we think many of these insights will hold true for everyone with Parkinson’s, not just those with these rare genetic changes, and this knowledge is already leading to the development of treatments that are showing significant promise.
Another way in which I believe that genetics will improve life for people with Parkinson’s in the future is by helping us to provide much more personalised treatments to individuals. Parkinson’s is a very variable condition. People develop it at different ages, experience different symptoms, and respond differently to treatments. I think genetics may help us understand this better, and hopefully one day we will be able to look at a person’s genetics to help us choose the right treatments for that individual.
Q. Is it possible to be involved in genetic research?
Yes, absolutely. I believe we have a huge amount more to learn about the genetics of Parkinson’s, including genetic variants that we haven’t discovered yet, and there are several research studies exploring this that need people to participate.
We set up the Parkinson’s Families Project to search for the next pieces in this complex and ever-expanding puzzle. In this project we’re looking for people who developed symptoms before the age of 45 and or who have a family history of the condition. We’re also keen to involve their close family members so that we can compare the genetic makeup of people with and without Parkinson’s.
Participants donate a blood sample, provide a medical history and complete some questionnaires. We can then look for new genes that may be important in Parkinson’s.
As with many research studies, participants can choose to be notified if genetic testing may be relevant to them or their family. They can then have follow-up NHS genetic testing, if they wish.
A huge thank you to Professor Huw Morris who is Consultant Neurologist and Professor of Clinical Neuroscience at the Royal Free Hospital, National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology.
Read the other articles in this series:
And if you have further questions about the genetics of Parkinson’s please add them in the comments section below or email us at research@parkinsons.org.uk.
