Molybdenum cofactor sulfurase (MOCOS) gene encodes an enzyme which is involved in purine metabolism. Recent experiments have shown down-regulation of MOCOS in adult nasal olfactory stem cells of individuals with autism spectrum disorder (ASD). In the current study, we genotyped two single nucleotide polymorphisms (SNPs) within coding regions of MOCOS gene (rs594445 and rs1057251) in 406 ASD patients and 411 age and sex-matched controls. The A allele of the rs594445 SNP was more prevalent among ASD cases compared with controls (OR (95% CI) = 1.33 (1.07-1.64), adjusted P value = 0.02). This SNP was associated with risk of ASD in co-dominant (AA vs. CC: OR (95% CI) = 2.00 (1.22-3.23), adjusted P value = 0.04) and recessive (AA vs. CC + AC: OR (95% CI) = 1.86 (1.16-2.98), adjusted P value = 0.02) models. The other SNP was not associated with risk of ASD in any inheritance model. There was no LD between rs594445 and rs1057251 SNPs (D' = 0.03, r2 = 0.14). The C T haplotype (rs594445 and rs1057251, respectively) had a protective role against ASD (OR (95% CI) = 0.76 (0.62-0.92), adjusted P value = 0.02). Other estimated haplotypes distributed equally between cases and controls. Based on the results of current study, the rs594445 SNP might be regarded as a risk locus for ASD in Iranian population.
Keywords: Autism spectrum disorder; MOCOS; Molybdenum cofactor sulfurase; rs1057251; rs594445.