Abstract

Background: The associations of MTHFR polymorphisms with risk of attention deficit and hyperactivity disorder (ADHD) are poorly elucidated. This study was performed to evaluate the association of MTHFR polymorphisms with ADHD risk in Iranian children. Methods: This case?control study included 214 children with ADHD and 220 healthy subjects. The MTHFR 677C?>?T and 1298A?>?C polymorphisms were genotyped by an ABI PRISMs 7500 real-time PCR System. The odds ratios (ORs) with 95 confidence intervals (CIs) were used to assess the strength of the association. Results: The MTHFR 1298A?>?C polymorphism CC genotype (OR= 1.526, 95 CI 1.004?2.320, p?=?0.048) and C allele (OR= 1.336, 95 CI 0.1023?1.745, p?=?0.034) were associated with an increased risk of ADHD. There was no significant association between MTHFR 677C?>?T polymorphism and increased risk of ADHD. Conclusions: Our results revealed that the MTHFR 1298A?>?C polymorphism but not the MTHFR 677?C?>?T is associated with increased risk of ADHD in Iranian children.