HDAC8 and Cornelia de Lange syndrome: Longitudinal investigations with larger samples of patients with CdLS-causing gene variants (e.g., inclusion of those with pathogenic variants in HDAC8, SMC3, etc.), comparison groups of idiopathic autism spectrum disorder and/or intellectual disability, and other clinical groups with overlapping CdLS-like features, such as pathogenic variants in EP300, AFF4, NAA10, and TAF6, are necessary to disentangle the different disease pathways that underline the CdLS neurobehavioral phenotype.