BDNF Val66Met polymorphism in primary adult-onset dystonia: A case-control study and meta-analysis

Background A polymorphism in brain‐derived neurotrophic factor (BDNF) (Val66Met) has been reported as a risk factor in primary dystonia. However, overall the results have been inconclusive. Our aim was to clarify the association of Val66Met with primary dystonia, and with the most prevalent clinical subtypes, cervical dystonia and blepharospasm. Methods We conducted a Spanish multicenter case‐control study (including 680 primary dystonia patients and 788 healthy controls) and performed a meta‐analysis integrating our study and six previously published studies (including a total of 1,936 primary dystonia patients and 2,519 healthy controls). Results We found no allelic or genotypic association with primary dystonia, cervical dystonia, or blepharospasm risks, for the allele A (Met) from a BDNF Val66Met polymorphism in our case‐control study. This was confirmed by results from our meta‐analysis in white and mixed ethnic populations in any genetic model. Conclusion We did not find any evidence supporting the association of the BDNF Val66Met polymorphism with primary dystonia. © 2014 International Parkinson and Movement Disorder Society