Walton et al. (2017) reported that DNA methylation at birth differentiated ADHD-related trajectories in a population-based cohort across multiple genomic locations implicating e.g. genes coding for SKI (involved in neural tube development), ZNF544 (previously linked to ADHD), and ST3GAL3 (mutations cause intellectual disability), although none of these genes maintained an association with ADHD trajectories at age 7 years. Here, SKI is linked to attention deficit-hyperactivity disorder.