BDNF Val66Met polymorphism and protein levels in amniotic fluid

Abstract

Background: Brain-Derived Neurotrophic Factor (BDNF) is a neurotrophin which plays survival- and growth-promoting activity in neuronal cells and it is involved in cellular plasticity mechanisms as it controls activity dependent synaptic transmission. A functional polymorphism (Val66Met) in the pro-region of BDNF, which affects the intracellular trafficking of proBDNF has been associated with memory and cognitive deficits as well as to an increased susceptibility for several psychiatric disorders especially those with a neurodevelopmental origin. To date, no study has evaluated the influence of the Val66Met polymorphism on BDNF levels in a peripheral system that may reflect fetal neurodevelopment. Therefore we investigated in amniotic fluids (AF) obtained from 139 healthy women during 15-17 week of pregnancy, BDNF protein levels in correlation with the Val66Met polymorphism.

Results: Interestingly we found a significant BDNF protein levels reduction in 55 Met carriers (Val/Met and Met/Met) (p = 0.002) as compared to 84 non carriers (Val/Val), and no effect of fetus gender, maternal age or gestation week on BDNF levels has been observed.

Conclusion: These results, although explorative, indicate that during fetal life the Val66Met genotype might influences BDNF protein levels in AF supporting the involvement of this polymorphism in behavioral and functional brain individual differences in the adulthood.

Figure 1

BDNF protein levels distribution in 139 AFs (84 Val66Val individuals and 55 Met66 carriers). BDNF protein levels, evaluated by ELISA method, are significantly reduced in Met carriers versus non carriers The amount of BDNF expressed in pg/ml was 10.02 ± 9.62 for Met allele carriers and 15.88 ± 12.71 for non carriers (Mann-Whithney test: p = 0.002). In the group of Met allele carriers, the Met66Met are evidenced in black. Error Bars indicates the mean of values ± standard deviation.