Protein-activated kinases mediate spine morphogenesis and synaptic plasticity. PAK3 is part of the p21-activated kinases (PAKs) family of Ras-signaling serine/threonine kinases. Pathogenic variants in the X-linked gene PAK3 have been described in patients with neurodevelopmental syndromes. We analyzed an Italian family with sleep-related hypermotor epilepsy, intellectual disability, psychiatric and behavioral problems, and dysmorphic facial features. A novel PAK3 c.342_344del …