NSD2 and microcephaly: Loss of function mutations in NSD2 have been associated with ASD across multiple genetics studies (De Rubeis et al., 2014; Wang et al., 2016; Yuen et al., 2017), and replicate several of the clinical presentations of Wolf–Hirschhorn syndrome including microcephaly, global developmental delay, and ID, but do not present seizures (Boczek et al., 2018; Barrie et al., 2019; Wiel et al., 2022).