Over recent years, researchers have been identifying genetic variations associated with an increased risk of developing Parkinson’s. Approximately 20% of people diagnosed have one or sometimes two of these genetic risk factors. Now, a recent study has shown that having the combination of two particular genetic risk factors for Parkinson’s has a surprising result.

DNA (Deoxyribonucleic acid) contains the genetic instructions for the development and function of living things. Our DNA is rather like a biological blueprint that contains all the information necessary to build and maintain our bodies, and it is carried in almost every cell. Tiny variations in our DNA are what in large part make each of us unique; but whilst some genetic variations bring positive benefits, some leave us vulnerable to disease.

A new study looking into genetic variations in people with Parkinson’s, provides evidence that having a combination of two particular genetic risk factors for Parkinson’s may not make that person’s Parkinson’s doubly worse, but rather have a very limited impact.

Read more about the study

Researchers collected DNA and clinical assessment data for 1193 individuals with Parkinson’s. Of these, 128 were found to have a genetic variation in a region of DNA called the GBA gene. People with GBA-associated Parkinson’s have been reported to have a faster progressing form of the condition, with increased risk of cognitive issues. Another 155 of the 1193 individuals were found to have a genetic variation in their LRRK2 gene. People with LRRK2-associated Parkinson’s typically have a slower progressing form of the condition.

Interestingly, the researchers identified 21 individuals within their dataset who had both a GBA genetic variant AND a LRRK2 genetic variant. But when they looked at the clinical assessment data for these individuals, they found that rather than making the Parkinson’s progression twice as bad, these individuals appeared to be very similar to people with just LRRK2-associated Parkinson’s (a slower progressing form of Parkinson’s). The result suggests that the combination of GBA- and LRRK2- genetic variants may reduce the impact of GBA-associated Parkinson’s.

While the biological mechanism for this effect is still to be determined, the study’s findings could have important implications for clinical trials assessing new treatments. People with Parkinson’s who have these genetic variations will need to be identified and carefully balanced between study groups in order to avoid their genetics affecting the potential outcomes of the study.

Cure Parkinson’s is supporting the PD Frontline study in the UK, which is a DNA analysis investigation attempting to identify people with specific genetic variations.

By carefully identifying individuals with these genetic variations, we are hoping to have cohorts of predetermined people ready for certain trials to help speed up the clinical testing of drugs like ambroxol, which is being targeted towards the genetic GBA-associated Parkinson’s.