Autism is a neurodevelopmental disorders that manifests before 3 years of age, more common in boys. Whereas causes of autism remain uncertain, it is influenced by genetic and environmental factors. Recent studies have shown that the genes involved in the folate metabolism pathway may play an important role in autism. Methionine synthase reductase (MTRR) is a key enzyme that plays an important role in the homocysteine/folate metabolism and has been shown to be implicated in neurological disorders including autism. In this study, 356 subjects were studied, which consists of 142 autistic children and 214 nonautistic control. Genomic DNA was extracted from blood samples. Genotype of MTRR 66A>G gene was performed using polymerase chain reaction-allele specific PCR (AS-PCR). The genotype frequencies of AA, AG and GG in the children with autism were 9.9%, 76.0% and 14.1%, respectively and in control group were 13.1%, 86.0% and 0.9%, respectively. The allele frequencies of A, G in the children with autism were 48.0%, 52.0%, respectively and in control group were 56.0%, 44.0%, respectively. Statistical analysis showed that there is a significant correlation in the genotype between two groups (OR=20, 95% CI=4.1 to 98, P<0.001). It is concluded that MTRR A66G polymorphism is associated with autism in a population in northern Iran. More studies with larger number should be done to confirm this result.
Autistic Disorder

Objective: To evaluate the effect of iron on the attention deficit hyperactivity disorder, treated with methylphenidate. Methods: This double-blind, randomized placebo-controlled clinical trial was performed on 50 children with attention deficit hyperactivity disorder under the treatment of methylphenidate, with ferritin levels below 30 ng/ml and absence of anemia. They were randomly assigned into two groups of ferrous sulfate and placebo, for 12 weeks. Conners' Parent Rating Scale (CPRS) was used to assess the outcome in the first, sixth, and twelfth weeks. Results: Almost all CPRS subscales improved in the ferrous sulfate group from the baseline to the endpoint, although only the changes in conduct subscale scores were significant (p = 0.003). There was no significant difference in score changes between two groups in intergroup comparison. Also, the score of learning problems (p = 0.007) in the first six weeks, and conduct (p = 0.023) and psychosomatic (p = 0.018) subscales in the second six weeks were improved in the ferrous sulfate group compared with the placebo group. Conclusion Our study showed promising effects of iron supplementation in the improvement of subscales of the CPRS.