BDNF Val66Met homozygosity does not influence plasma BDNF levels in healthy human subjects.

A putative pathway by which the BDNF Val66Met polymorphism (rs6265) leads to aberrant phenotypes is its influence on plasma BDNF. Research into the impact of rs6265 on plasma BDNF has given rise to conflicting results. Moreover, most such studies have compared Met-carriers with Val-homozygous subjects. We therefore genotyped subjects from a population-based cohort (the Utrecht Health Project, N=2743) and assessed whether plasma BDNF differs between rs6265 homozygous groups. We maximized the number of Met-homozygous subjects in whom we measured plasma BDNF, resulting in plasma BDNF being available for 19 Met-homozygous and 42 matched Val-homozygous subjects. Mean concentrations (S.D.) were 1963.1 (750.1) and 2133.2 pg/ml (1164.3) for the Val/Val and Met/Met groups, respectively. Using ANOVA, no differences in plasma BDNF between the two groups were detected. In conclusion, these results add to a growing body of evidence indicating that allelic variation at rs6265 does not have medium to large effects on plasma BDNF concentrations.