Rugonersen sodium is a locked-nucleic acid (LNA)- modified antisense oligonucleotides (ASOs), and results in reduction of ubiquitin-protein ligase E3A (UBE3A) silencing. Angelman syndrome (AS) sodium is a severe neurodevelopmental disorder caused by the loss ofneuronal E3 ligase UBE3A, Rugonersen has been used for AS reasearch.