The associations of zinc and GRIN2B genetic polymorphisms with the risk of dyslexia.

ABSTRACT

BACKGROUND: Zinc is an essential trace element and a number of studies have identified the importance of zinc in neurodevelopment in children. However, epidemiologic data on the associations of zinc and genetic susceptibility with the risk of dyslexia are limited. We aimed to investigate whether genetic polymorphisms in GRIN2B genes modify the association between zinc levels and dyslexia risk. METHODS: A case-control study of 240 dyslexic children and 230 healthy controls was conducted in Wuhan, Hangzhou and Jining city in China from April 2017 to April 2018. Zinc concentrations in urine samples were measured with inductively coupled plasma-mass spectrometry (ICPMS). Multiple imputation was used to impute missing values of covariates. We applied multivariable logistic regression models to evaluate the effect in the study. RESULTS: After adjustment for potential confounders, we observed the associations of urinary zinc with dyslexia risk were modified by rs1805502 (Pinteraction = 0.048) in gene GRIN2B. About 2-fold increase in creatinine-corrected zinc levels was significantly related to a reduced risk of dyslexia [odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.29, 0.95 in rs1805502 mutation carriers]. CONCLUSIONS: The associations between zinc levels and dyslexia risk were modified by polymorphism of rs1805502 in gene GRIN2B.