Researchers at Massachusetts General Brigham have engineered a bespoke CRISPR-Cas9 base editor to precisely correct the ACTA2 mutation causing multisystemic smooth muscle dysfunction syndrome (MSMDS), a rare pediatric vascular disease with no effective treatment. Using mouse models and AAV delivery, the gene editing therapy improved survival and reduced disease phenotypes. The study, published in Nature Biomedical Engineering, demonstrates the potential of precision gene editing for devastating genetic vascular disorders.