title: MTHFR C677T is not a risk factor for autism spectrum disorders in South Brazil.
abstract: Many studies have suggested that autism may be associated with metabolic abnormalities in the folate/homocysteine pathway, which is involved in DNA methylation, thus altering gene expression. One of the most important polymorphisms in this pathway is C677T of the methylenetetrahydrofolate reductase gene, because the T allele is associated with a decrease in enzymatic activity. We evaluated the association between C677T polymorphism and autism spectrum disorders through a case--control study. In addition, we analyzed the influence of this polymorphism on certain autistic behaviors like complex body movements, self-injury and averted gaze according to the Autism Diagnostic Interview-Revised. The analyses involved 151 children with idiopathic autism spectrum disorder and 100 healthy control children. The frequency of the T allele was 0.38 for the case group and 0.35 for the control group (P=0.77). The genotypic distribution did not show significant differences between cases and controls (P=0.72), nor association between the T allele and selected behaviors.
authors.affiliation: Departamento de Genética, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Pollyanna Almeida Costa
authors.initials: PA
authors.lastname: dos Santos
authors.forename: Dânae
authors.initials: D
authors.lastname: Longo
authors.forename: Ana Paula Carneiro
authors.initials: AP
authors.lastname: Brandalize
authors.forename: Lavínia
authors.initials: L
authors.lastname: Schüler-Faccini
mesh_terms: D001321:Autistic Disorder / Q000201:enzymology* / Q000235:genetics*; D001938:Brazil; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)