SETD1A and Neurodevelopmental delay: Consequently, non-human models have targeted haploinsufficiency (Setd1a+/-), with current mouse models employing either frameshift mutations to exon 7 or 15 or disruption to exon 4 via an upstream LacZ/Neo cassette [17–20] to investigate the mechanisms of Setd1a function and how it might influence NDD.