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