The strongest evidence comes from recurrent de novo variants that alter E237 of KIF5C and are associated with a neurodevelopmental syndrome that includes epilepsy, intellectual disability, autistic features and absent language (Cavallin et al., 2016; Michels et al., 2017; Poirier et al., 2013; Willemsen et al., 2014). The gene discussed is KIF5C; the disease is epilepsy.