NGLY1 deficiency is a complex neurological syndrome resulting from a shortage of the enzyme N-glycanase 1. This enzyme assists in the removal of dysfunctional proteins from the body, and has other regulatory functions. Symptoms and severity of this disorder can vary dramatically among affected individuals and have been reported to include developmental delays, movement disorder, weak muscle tone, liver abnormalities, seizures and an inability to produce tears.
NGLY1 deficiency is the first known congenital disorder of deglycosylation (CDDG), as opposed to other known congenital disorders of glycosylation (CDGs). The disorder is inherited in an autosomal recessive genetic manner, meaning that a child is affected when each parent passes on one copy of the damaged gene.