Antisense oligonucleotides (ASOs) are a promising therapeutic modality for monogenic disorders, offering precise RNA-targeting strategies to modulate gene expression. Despite challenges in delivery, toxicity, and off-target effects, ASO therapies have advanced rapidly, with several approved treatments and numerous candidates in clinical development. Their application spans neurogenetic, metabolic, and oncologic disorders, also with emerging n-of-1 approaches for ultra-rare conditions. This review describes the different mechanism of how ASOs work depending on their chemistry and discusses the considerations of which patients could be amendable for treatment highlighting the role of human genetics for decision making.