UC Davis

Key PointsThe aetiology of autism spectrum disorder is complex: hundreds of genetic variants and various environmental factors have been implicated as risk factors.Epigenetic mechanisms such as DNA methylation and chromatin structure are optimally poised at the intersection of genes and environment in autism aetiologies.DNA methylation includes multiple modification types, some of which are specifically enriched in the nervous system.The association of DNA methylation with gene expression and the dynamics of modification changes during brain development depend on genomic context.DNA-methylation patterns are highly dynamic across the lifespan, with the biggest changes occurring around implantation and in the transition between fetal to early postnatal life.Alterations in DNA methylation have been observed by both candidate gene and genomic studies of the post-mortem brain in autism. Future investigations of the autistic brain and surrogate tissues using larger sample sizes and whole-genome sequencing approaches hold promise for improved understanding and potential molecular diagnosis of autism risk.