The NGLY1 gene provides instructions for making an enzyme called N-glycanase 1. This enzyme is involved in a process called deglycosylation, by which chains of sugar molecules (glycans) are removed from proteins. Specifically, N-glycanase 1 removes glycans from misfolded proteins. This step is thought to be essential for certain abnormal proteins to be broken down (degraded).
At least 13 mutations in the NGLY1 gene have been found to cause NGLY1-congenital disorder of deglycosylation (NGLY1-CDDG). This condition affects many body systems, causing delayed development, movement abnormalities, problems with liver function, eye abnormalities, and a reduction or absence of tears (hypolacrima or alacrima). These mutations impair production of the N-glycanase 1 enzyme, resulting in a severe reduction or absence of the enzyme's function. Without the removal of glycans, certain misfolded proteins cannot be broken down. It is thought that the abnormal proteins accumulate and form clumps (aggregates) in cells. These aggregates may damage cells in the brain, liver, and eyes, leading to the signs and symptoms of NGLY1-CDDG.
- peptide-N(4)-(N-acetyl-beta-glucosaminyl)asparagine amidase isoform 1