The frequency of these genotype in children with autism (16.1%) was significantly higher (odds ratio [OR] = 2.04; 95% confidence interval [CI] = 1.07, 3.89; p = 0.03) than those in controls (8.6%), suggesting that MTHFR C677T is a risk factor for autism in children of this population [52]. Here, MTHFR is linked to autism.