Complete screening for glucocerebrosidase mutations in Parkinson disease patients from Greece.

Mutations in beta-glucocerebrosidase gene (GBA) have been implicated in Parkinson disease (PD). A Greek cohort of 172 PD patients and 132 control individuals were screened for GBA mutations by complete sequencing of the gene's exons. Four mutations previously associated with Gaucher disease and/or Parkinson's disease (L445P, D409H, E326K, H255Q) were detected, as well as five newly identified variants (R329H, L268L, S271G, T428K, V460L), providing for the first time data regarding the frequency of GBA mutations among PD patients and controls, in the Greek population. H255Q was the most common GBA mutation among Greek PD patients (4/172). V460L was only found in control individuals (2/132). Overall, GBA mutations were significantly overrepresented in a subgroup of early onset PD patients, compared to controls (P = 0.019, OR = 4.2; 95%CI = 1.28 -- 13.82), suggesting that GBA mutations may modify age of onset for PD.