Single-gene manipulations of developmental epileptic encephalopathies (e.g., SCN1A, SCN1B, SCN8A, and DEPDC5) and long-QT syndromes (e.g., KCNA1 and KCNQ1) have been used to model SUDEP.6,42 In these studies, the contribution of a single gene to SUDEP can be demonstrated, but these models lack consideration of the genetic complexity of the SUDEP response.43–46 We identified several novel inbred mouse strains with extreme sensitivity to seizure-induced sudden death, modelling SUDEP, and with likely different causal mechanisms. Here, SCN1A is linked to developmental and epileptic encephalopathy.