BDNF gene has been implicated in the development of cognition and language. Meanwhile, exposure to metals might interact with
BDNF gene to increase the risk of
neurodevelopmental disorders. The present study aimed to explore the association between
BDNF genetic polymorphisms and dyslexic risk and examine whether
BDNF polymorphisms would interact with
metal exposures, jointly contributing to
dyslexia. Among a case-control study composed of 238 children with
dyslexia and 228 healthy controls, the
BDNF genetic polymorphisms were genotyped by the Sequenom MassARRAY system, and the exposure to eight metals, such as lead (Pb),
mercury (Hg) and
copper (Cu), were measured using an inductively coupled plasma-mass spectrometer (ICP-MS). Multivariable logistic regression models were used to assess the adjusted odds ratios (
ORs) and 95% confidence interval (CI) of
dyslexia. After multivariate adjustment, significant associations of dyslexic risk with rs6265 polymorphisms of the
BDNF gene were observed (OR = 1.99; 95% CI: 1.15-3.44). Furthermore, exposure to Cu could interact with rs6265 to increase the risk of
dyslexia (P interaction = 0.045). High-Cu children with the rs6265 TT genotype were more likely to have
dyslexia compared with low-Cu children carrying CC + CT genotypes (OR = 3.19; 95% CI: 1.38-7.39). The findings of this study suggested that the polymorphism of rs6265 in
BDNF gene could interact with Cu exposure to increase the occurrence of
dyslexia.