Interestingly, while the typical mutations of KCNT1 leading to EIFMS are gain of function and KCNT1 would be even more tolerant than KCNT2 to loss-of-function variants (pLI score at 0.01 at the ExAC database, http://exac.broadinstitute.org/), a Phe932Ile loss of function variant in KCNT1 was reported in a patient with severe epilepsy, delayed myelination and leukoencephalopathy (Vanderver et al., 2014; Evely et al., 2017), further indicating that decreased activity of KNa channels can indeed be associated with severe neurological manifestations including epilepsy. The gene discussed is KCNT1; the disease is Leukoencephalopathy.