Researchers led by UC San Diego reported that personalized antisense oligonucleotides reduced seizure frequency in two boys with SCN2A-related developmental and epileptic encephalopathies, as published in Nature Medicine. The study used individualized ASO designs matched to inherited disease variants, including a gain-of-function SCN2A mutation. In one case, the therapy enabled independent walking, while both children had seizures refractory to more than 10 antiseizure medications. Ionis Pharmaceuticals supported design and testing, underscoring how ASOs can target root genetic mechanisms for rare, ultra-rare neurological disorders.