Understanding GBA, A Genetic Risk Factor for Parkinson’s
Wednesday, 31st October 2012

Last week, The Michael J. Fox Foundation (MJFF) hosted a workshop to delve deeper into understanding how specific mutations in a gene called glucocerebrosidase (GBA) might cause Parkinson’s disease (PD). The group met in New York to make recommendations as to what the research field can do to continue to drive forward drug compounds targeting GBA.

Since first being tied to Parkinson’s in 2008, research has pointed to GBA as the most common genetic risk factor linked to the clumping of the protein alpha-synuclein that takes place in all people with the disease. But it’s hard to tell exactly what this means; researchers still don’t recognize why, or how, mutations in GBA might lead to this alpha-synuclein aggregation.

Here’s what scientists do know:

GBA is an enzyme found in cellular subunits called lysosomes, which are basically garbage disposals designed to break down and dispel certain unwanted fats called from within our cells. Mutations in GBA seem to cause these lysosomes to lose their ability to get rid of these fats, and this can cause complications.

And here’s what scientists have hypothesized:

In Gaucher’s disease, which is caused by mutations in the GBA gene, too many of these fats cause the liver and spleen to become enlarged. In PD, it’s believed that their presence might lead to alpha-synuclein build-up, and also, to the progressive cell death in the brain that is common to Parkinson’s.

Still, scientists wonder, is this alpha-synuclein aggregation tied to mutations in GBA due to the mutation in the gene itself, or, as noted above, could it be a response to the extraneous build-up of these fats?

Researchers have more to do to nail down the true nature of the culprit. Better understanding what’s at work is crucial to developing potential treatments to counteract these processes. And the ramifications could be widespread: If scientists can understand more about how mutations in GBA lead to this alpha-synuclein build-up and eventually PD, they might be able to create new drugs for everyone with the disease, not just those with the mutation (Since everyone with PD experiences alpha-synuclein aggregation).

This week’s workshop was meant to address the gene’s relationship to parkinsonism, how it compares to other genetic risk factors associated with PD such as LRRK2, and possible ways to pharmacologically target GBA. The major takeaway: The gene offers exciting potential, but we have a lot more to understand about its role in PD. Once understood, it could offer an interesting target for potential drug compounds. Those gathered were also intrigued about how measuring GBA in body fluids could serve as a biomarker for PD.