Because of known associations between the genes SCN1A and SCN5A and sudden death, and shared mechanisms and patterns of expression in genes encoding many voltage‐gated sodium channels (VGSCs), we hypothesized that individuals dying from SUDP have pathogenic variants across the entire family of cardiac arrhythmia‐ and epilepsy‐associated VGSC genes. Here, SCN5A is linked to cardiac arrhythmia.