EE patients display severe and often drug-resistant neonatal seizures and psychomotor retardation (Weckhuysen et al., 2012), and de novo EE mutations in KCNQ2 and KCNQ3 induce multiple defects in current and surface expression of Kv7 channels (Weckhuysen et al., 2012, 2013; Milh et al., 2013; Miceli et al., 2015; Kim et al., 2018; Zhang et al., 2020). The gene discussed is KCNQ3; the disease is ethylmalonic encephalopathy.