DNA methylation signatures (“episignatures”) can be used as biomarkers of genetic aberrations, clinical phenotypes, and environmental exposures in rare diseases. Episignatures are utilized in molecular diagnostics and can clarify variants of uncertain significance. A growing number of disease genes, including epilepsy genes, exhibit robust and reproducible episignatures. However, whether SCN1A, the most prominent epilepsy gene, has one or more episignatures has not yet been determined. …