Because we previously reported an association between ADHD and DNA methylation at sites annotated to VIPR2 and MYT1L specifically in boys31, we first examined sex-by-diagnosis interaction effects among all probes annotated to these two genes (239 probes) at an adjusted significance threshold of p < 0.0002 (0.05/239). This evidence concerns the gene MYT1L and attention deficit-hyperactivity disorder.