In a blind analysis that compared these carriers (LRRK2-PD, n = 15; asymptomatic carriers, n = 16) with either idiopathic PD or healthy controls, the assay sensitivity was surprisingly rather low (40% in LRRK2-PD, 19% in the asymptomatic carriers) in the former group, whereas it was comparable to previous studies (90%) in the idiopathic (non-genetic) PD group. This evidence concerns the gene LRRK2 and Parkinson disease.