Genetic Correction of the Most Common Mutation Causing Primary Hyperoxaluria Restores Enzyme Localization and Oxalate Metabolism

Our research aimed to model primary hyperoxaluria type 1 in vitro using a stem cell model and assess the potential of adenine base editors in correcting the most common pathogenic AGXT genetic variant, c.508G>A (Gly170Arg), which leads to oxalate accumulation due to alanine‐glyoxylate aminotransferase mislocalization. Patient‐derived fibroblasts were induced to pluripotent stem cells, genetically corrected with adenine base editing, and subsequently differentiated into hepatocyte‐like cells in parallel with their non‐corrected isogenic counterparts. Enzyme localization was assessed through immunocytochemistry and confocal microscopy. The key metabolites associated with the disease were analyzed using liquid chromatography‐mass spectrometry to evaluate the metabolic phenotype. Finally, lipid nanoparticle formulations were designed and tested as an in vivo‐applicable delivery method for base editors. All induced pluripotent stem cell lines successfully differentiated into hepatocyte‐like cells and expressed essential hepatocyte markers, including ALB, HNF1A , and AGXT . Adenine base editor‐mediated genetic correction of the pathogenic AGXT mutation restored enzyme localization into peroxisomes and diminished oxalate accumulation without significant off‐target effects. Base editor mRNA and AGXT variant targeting single guide RNA encapsulated within lipid nanoparticles mediated gene correction in the hepatocyte‐like cell model. Using an in vitro model of primary hyperoxaluria type 1, we showed that base editor‐mediated genetic correction of the most common hyperoxaluria‐causing variant corrects enzyme mislocalization from mitochondria to peroxisomes and improves metabolic function. These results propose gene correction as a potential therapeutic approach to hyperoxaluria.