Similar strain dependencies occur across multiple models: Scn2a Q54 variants show mild phenotypes on C57BL/6J but severe epilepsy on SJL/J backgrounds due to dominant modifier alleles [100,191], while Scn8a V929F variants produce more severe spike-wave discharges on C3HeB/FeJ compared with C57BL/6J backgrounds [192]. Here, SCN2A is linked to epilepsy.