In contrast, when crossed with C57BL/6J (B6) mice, the resulting [B6 × 129]F1.Scn1a+/− mice recapitulated core features of Dravet syndrome, including spontaneous seizures and epilepsy, and a high incidence of SUDEP-like death in the first month of life (Miller et al. 2014). This evidence concerns the gene SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.