Interesting. Increasing glucocerebrosidase activity seems to be effective; not only for people with GBA gene, but also for the others.
As far as I understood each cell has a lysosome in which garbage is stored and later on chopped by this enzyme. People who carry a mutation in the GBA gene, have a lack of glucocerebrosidase activity, meaning the garbage doesn't get removed. This leads alpha synuclein to misfold which leads to parkinson's disease.
Amicus therapeutics is working on chaperones to increase glucocerebrosidase activity. I wonder whether there is some gene therapy in the pipeline that can overexpress the glucocerebrosidase enzyme ...