Some were based on the detection of a de novo CNV, which led to the description of more patients with CNVs or mutations at the ARID1B locus or focused on a closely defined CSS cohort (Santen et al., 2012, 2013; Wieczorek et al., 2013), whereas other studies reported on cohorts defined by the common feature of autism spectrum disorder (ASD) or ID. Here, ARID1B is linked to atrial septal defect.