β-Glucocerebrosidase gene (GBA) mutations have been identified as a risk factor for the development of Parkinson's disease (PD) in different ethnic groups. In Northern Greece significant association was only found in early onset PD patients (EOPD). Eight different GBA mutations were investigated in two cohorts of ethnic Greek patients with sporadic Parkinson's disease from Thessaly (n=100, cohort A) and Athens (n=105, cohort B). Age-gender-ethnicity matched healthy individuals from the same areas were included as controls (n=206). Statistically significant overrepresentation of GBA mutation carriers in the PD patients compared to controls was observed (p=0.006; OR=3.24, 95% CI=1.35-7.81). The association was reinforced in EOPD patients (p= 0.000; OR=11.37, 97% CI 3.73-34.6). PD patients harboring GBA mutations had an earlier onset of symptoms than non-carriers (p=0.034, p=0.004). Differences regarding the type of mutations and/or their relative frequencies were observed between cohorts. In conclusion, GBA mutations were identified with increased frequency in both geographical cohorts of sporadic PD patients compared to controls, the difference being statistically significant only in cohort A. An impressive association with EOPD was found, one third of the EOPD patients harboring a GBA mutation. Genetic and/or environmental factors may account for the observed differences in the two geographical cohorts studied. Objective: To characterize the saccadic eye movement abnormalities in patients with chronic neuronopathic Gaucher disease (GD3) in relationship to neurological and neurophysiological abnormalities. Methods: N=15 patients with GD3, age 8-28 years, prospective follow up (up to 4 years), saccadic eye movements (search coil method), neuropsychological and neurophysiological testing. Results: Patients with GD3 had a significantly higher regression slope of duration vs amplitude and peak-amplitude vs amplitude compared to healthy controls for horizontal/vertical saccades. Saccadic latency was significantly increased for horizontal saccades. Downward saccades were more affected than upward saccades. Regression slopes of horizontal vs vertical saccades for duration vs amplitude and peak-amplitude vs amplitude were significantly correlated (r=0.31, p<0.005) as was horizontal vs vertical saccade latency (r= 0.68, p<0.005). These abnormalities became more pronounced over time in some patients. There was a significant correlation between verbal IQ (p=0.03), performance IQ (p=0.04), full-scale IQ (p=0.02) and the downward saccade slope and between vertical saccade slope and the performance on the Purdue Pegboard when patient uses both hands (p=0.01). There was poor correlation between BAER, SSEP and saccadic eye movement parameters. Conclusions: Saccadic function and oculo-manual dexterity abnormalities are likely useful for studying neurological function in patients with GD3. Diagnosis for Gaucher Disease(GD) is based on beta-glucosidase(GBA) assay on leukocytes and chitotriosidase(CT) on plasma. Lately dried blood spots(DBS) are been used as screening, but not as final diagnosis because it's not established a measurement of specific activity. The aim of this study is to establish the best conditions of DBS elution to measure the specific activity of GBA and CT using total protein assay. DBS from 15 healthy volunteers and 8 GD patients were used. One punch of each sample was eluted using 40μL of sodium-phosphate-buffer(pH7) and tested for four incubation periods(10, 20, 30 and 60minutes) and two temperatures(30°C and 37°C). A microplate 4-MU fluorimetric assay for CT and GBA and a protein assay using 10μL of each elution was performed after. It was possible to measure activity of GBA and CT on DBS using a previous elution with pH7 buffer. The enzymes had higher activity with the 37°C elution than 30°C, so was protein(p<0.05). Because the determination of specific activity takes in consideration the protein amount, there was no statistically significant difference between temperatures and elution time. It was able to differentiate the healthy volunteers from the GD patients with a p=0.002 for CT and p=0.0002 for GBA.