Aspartylglucosaminuria (AGU, OMIM 208400) is a rare lysosomal storage disorder that is caused by a deficiency of the aspartylglucosaminidase (AGA; N4-(β-N-acetylglucosaminyl)-L-asparaginase, EC 3.5.1.26) enzyme. This evidence concerns the gene AGA and lysosomal storage disease.