Defective DPAGT1 causes CDG-1j, CMSTA2

UDP-N-acetylglucosamine--dolichyl-phosphate N-acetylglucosaminephosphotransferase (DPAGT1) catalyses the initial committed step in the biosynthesis of dolichyl pyrophosphate-oligosaccharides. Defects in DPAGT1 cause congenital disorder of glycosylation 1j (DPAGT1-CDG, previously known as CDG-1j; MIM:608093), a multisystem disorder characterised by under-glycosylated serum glycoproteins. Congenital disorders of glycosylation result in a wide variety of clinical features, such as defects in the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency. Defects in DPAGT1 can also cause myasthenic syndrome, congenital, with tubular aggregates, 2 (CMSTA2; MIM:614750), characterised by muscle weakness of mainly the proximal limb muscles, with tubular aggregates present on muscle biopsy. Sufferers find walking difficult and fall frequently. Younger sufferers show hypotonia and poor head control. A disorder of neuromuscular transmission is detected on electromyography.

Summary from Reactome (R-HSA-4549356), read 2026-09-23.