ENU mutagenesis induced a A to T transversion at base pair 101,035,624 (v38) on Chromosome 15, or base pair 165,802 in the GenBank genomic region NC_000081. The mutation corresponds to residue 4861 in the mRNA sequence NM_001077499 (isoform 1) within exon 26 of 27 total exons and residue 4762 in the mRNA sequence NM_011323 (isoform 2) within exon 25 of 26 total exons. The mutation results in substitution of a lysine (K) for a premature stop codon (*) at amino acid 1570 in both isoforms of the SCN8A sodium channel. This model was generated at UT Southwestern Medical Center at Dallas.