While we could not detect changes in phosphorylation of Rab10 in this cohort, the reduction in Rab29 phosphorylation is the first indication of possible changes in LRRK2 activation in clinical samples from PD patients carrying the A53T-SNCA mutation; and bolsters the notion that LRRK2 function plays an important role in PD in general. This evidence concerns the gene LRRK2 and Parkinson disease.