NGLY1 deficiency: Novel variants and literature review

NGLY1 deficiency is a recently described autosomal recessive disorder, involved in deglycosylation of proteins, and for that reason grouped as the congenital disorders of deglycosylation together with the lysosomal storage disorders. The typical phenotype is characterized by intellectual disability, liver malfunctioning, muscular hypotonia, involuntary movements, and decreased or absent tear production. Liver biopsy demonstrates vacuolar amorphous cytoplasmic storage material. NGLY1 deficiency is caused by bi-allelic variants in NGLY1 which catalyzes protein deglycosylation.