Synergic effect of GSTP1 and blood manganese concentrations in Autism Spectrum Disorder

•We studied the synergistic effect of blood manganese levels (Mn) and GSTP1 in ASD.•Odds of ASD was higher in children with Mn ≥ 12 μg/L and GSTP1 Ile/Ile genotype.•Children with Mn ≥ 12 μg/L and GSTP1 Ile/Ile genotype had 4 times higher odds of ASD.•Children with Mn ≥ 12 μg/L and Ile/Ile genotype had 6 times higher adjusted odds of ASD.

We used data from 100 age- and sex-matched case-control pairs (age 2–8 years) from Jamaica to investigate whether there is an interaction between glutathione-S-transferase (GST) genes and blood manganese concentrations (BMC) in relation to Autism Spectrum Disorder (ASD). Our findings, indicate that among children who had the Ile/Ile genotype for GST pi 1 (GSTP1), those with BMC ≥ 12 μg/L had about 4 times higher odds of ASD than those with BMC < 12 μg/L, (P = 0.03) under a co-dominant genetic model. After adjusting for potential confounders, among the subgroup of children with genotype Ile/Ile, those with BMC ≥ 12 μg/L had about six times higher odds of ASD than those with BMC < 12 μg/L, (P = 0.04). The results were similar when a recessive genetic model was used. These findings suggest a possible synergic effect of BMC and GSTP1 in ASD. Since our analysis included a variety of genetic models and was not adjusted for multiple testing, replication in other populations is warranted.