2.5. Statistical analyses
All analyses were performed with SPSS software version 20.021. Statistical significance was defined as a p-value <0.05. Shapiro-Wilk test was used to determine whether variables were normally distributed. To assess statistical differences between cases and controls independent t-test or Mann-Whitney test, for non-normal distributed data, was used. T-test or Mann-Whitney was also used to identify the differences among different genotypes. Two-way ANOVA test with Bonferroni correction was conducted to explore the interaction effect between parents’ smoking and FA on methylation levels.
Results