SCN2A and ethylmalonic encephalopathy: Interestingly, gating changes leading to a persistent current seem to be a recurrent pathomechanism for SCN2A variants detected in EE patients, as this dysfunction has also been described previously as the mechanism of disease for the EE variants A263V (Liao, Anttonen, et al. 2010a) and V423L (Wolff et al. 2017).