2013), CREBBP (Codina‐Sola et al. 2015), CHD2 (O'Roak et al. 2014), PRRG4 (Yamamoto et al. 2014), and TSC1, at 9q34 (Henske et al. 2016). Notably, reduced expression of UBE3A has been associated not only with autism, but also with sleep homeostasis (Ehlen et al. 2015), a common feature altered in Kleefstra Syndrome. Here, PRRG4 is linked to Kleefstra syndrome.