AAV9-based PMM2 gene replacement augments PMM2 expression and improves glycosylation in primary fibroblasts of patients with phosphomannomutase 2 deficiency (PMM2-CDG).

Inherited deficiency of phosphomannomutase 2 (PMM2) (aka PMM2-CDG) is the most common congenital disorders of glycosylation (CDG) and has no cure. With debilitating morbidity and significant mortality, it is imperative to explore novel, safe, and effective therapies for the disease. Our Proof-of-Concept study showed that AAV9-PMM2 infection of patient fibroblasts augmented PMM2 expression and improved glycosylation. Thus, AAV9-PMM2 gene replacement is a promising therapeutic strategy for PMM2-CDG patients.