ThusC163S mutation is a pathogenic mutation frequently observed in N(4)-(beta-N-acetylglucosaminyl)-L-asparaginase (AGA, PDB Id: 1APY, 1APZ), which leads to aspartylglucosaminuria (AGU), an autosomal recessive inherited disorder of glycoprotein degradation. This evidence concerns the gene AGA and aspartylglucosaminuria.