MOGS-CDG: quantitative analysis of the diagnostic Glc3 Man tetrasaccharide and clinical spectrum of six new cases

Congenital disorders of glycosylation (CDG) are a clinically and biochemically heterogenous subgroup of inherited metabolic disorders. Most CDG with abnormal N-glycosylation can be detected by transferrin screening, however, MOGS-CDG escapes this routine screening. Combined with the clinical heterogeneity of reported cases, diagnosing MOGS-CDG can be challenging. Here, we clinically characterize ten MOGS-CDG cases, six previously unreported individuals, showing a phenotype characterized by dysmorphic features, global developmental delay, muscular hypotonia, and seizures in all patients and in a minority vision problems and hypogammaglobulinemia.