Interaction between a mixture of heavy metals (lead, mercury, arsenic, cadmium, manganese, aluminum) and GSTP1, GSTT1, and GSTM1 in relation to autism spectrum disorder

•Humans are exposed to mixtures of metals and other environmental chemicals.•We used mixture analysis to assess relative contribution of six metals in ASD.•We found a possible effect modification of GSTP1 with Mn, Pb, and Hg in ASD.•Our finding of interaction of GSTP1 with Mn in ASD has been reported previously.•Possible effect modification of GSTP1 with Pb, and Hg in ASD requires replication. Exposure to many environmental chemicals, including metals, often does not occur in isolation, hence requires assessment of the associations between exposure to mixtures of chemicals and human health. To investigate associations of a metal mixture of lead (Pb), mercury (Hg), arsenic (As), cadmium (Cd), manganese (Mn), and aluminum (Al) in children with autism spectrum disorder (ASD), additively or interactively with each of three glutathione S-transferase (GST) genes (GSTP1, GSTT1, and GSTM1). Using data from 266 case-control pairs of Jamaican children (2–8 years old), we fitted negative and positive generalized weighted quantile sum (gWQS) regression models to assess the aforementioned associations. Based on additive and interactive negative gWQS models adjusted for maternal age, parental education, child’s parish, and seafood consumption, we found inverse associations of the overall mixture score with ASD [MOR (95 % CI) = 0.70 (0.49, 0.99); P