Data from 2 distinct, unmedicated, early-stage Parkinson disease (PD) cohorts suggest that carrying 2 copies of the rs6265 Met66 allele (∼4% of the population) is associated with less severity in motor symptoms and potentially a slower rate of progression, a recent study found. A retrospective analysis was conducted using data collected in the DATATOP study. DNA samples (n=217) were genotyped for the Bdnf rs6265 variant, and the primary endpoint was time to initiate levodopa. The Parkinson's Progression Markers Initiative (PPMI) was used for validation (n=383).

• The primary endpoint of time to initiate levodopa was associated with a delay in subjects with 2 copies of the rs6265 minor (Met66) allele.
• Secondary endpoints were not different among genotypes.
• PPMI subjects with 2 Met66 alleles demonstrated significantly lower total and part III Movement Disorder Society – United Parkinson's Disease Rating Scale (MDS-UPDRS) scores at baseline, as well as more tremor-related symptoms, but not a delay in initiation of maintenance pharmacotherapy.