Sialidosis is a lysosomal storage disease caused by mutations in the NEU1 gene, which encodes sialidase neuraminidase 1. These mutations lead to enzyme deficiency and subsequently accumulation of oligosaccharides and sialylated glycopeptides in tissues and body fluids, which in turn lead to cell and organ dysfunction. There are no approved therapies. 
Three different AAV9 vectors encoding NEU1 were developed and tested by UMass Chan Medical School researchers in the preclinical setting in mice.