We explored the hypothesis that SETD1A haploinsufficiency contributes to neurodevelopmental disruptions associated with schizophrenia risk via alterations in DNA methylation.<h4>Study design</h4>We profiled DNA methylation in the frontal cortex of Setd1a+/- mice across prenatal and postnatal development using Illumina Mouse Methylation arrays. This evidence concerns the gene SETD1A and schizophrenia.