CDG-Id caused by homozygosity for an ALG3 mutation due to segmental maternal isodisomy UPD3(q21.3-qter)

Identification of the Gene Encoding the α1,3-Mannosyltransferase (ALG3) inArabidopsisand Characterization of DownstreamN-Glycan Processing

“…In humans, a defect in the ALG3 gene causes congenital disorder of glycosylation-type Id. At present, only four patients have been described in the literature (Stibler et al, 1995;Korner et al, 1999;Denecke et al, 2004Denecke et al, , 2005Schollen et al, 2005;Sun et al, 2005). All known patients are homozygous for the mutation in the ALG3 gene, but all were shown to have leaky ALG3 expression.…”

Congenital Disorders of N-Glycosylation Including Diseases Associated With O- as Well as N-Glycosylation Defects

“…More recent patient reports (43)(44)(45) confirm that CDG-1d, apparent from the early weeks of life, is a severe encephalopathy, reminiscent of CDG-Ia and associated with dysmorphic facial and limb features that point at the prenatal expression of this inborn error of metabolism. In one patient the OFC at birth was small (43) and in another it was large (44).…”

“…They prove that prenatal diagnosis also of CDG-Id must depend solely on molecular screening of the ALG3 mutations. For details regarding the more recently reported mutant alleles, reading the original reports (41)(42)(43)(44)(45)(46) and consultation of OMIM is recommended.…”

Enrichment proteomics challenges and perspectives : analysis of the N-glycoproteome and plasma membrane proteome in glycosylation mutants and plant-pathogen interactions

“…Mutations in mammalian cells that affect N-glycan processing are linked to very severe phenotypes (Type II congenital disorders (Grunewald et al, 2002;Schollen et al, 2005)). In contrast, eliminating overall modifications to complex type N-glycans on plant glycoproteins has no or little effect on plant growth.…”

“…In eukaryotes N-glycans are involved in protein folding, protein folding quality control, polar protein localization and stability, ligand binding, endocytosis, immune recognition, inflammation and pathogenicity, cell signalling and cell motility (Varki, 1993;Parodi, 2000;Schollen et al, 2005;Sun et al, 2005). The importance of N-glycan modifications in mammalian cells is exemplified by the strong congenital disorders resulting from mutations in N-glycan processing (Grunewald et al, 2002;Schollen et al, 2005). In contrast, in plants the structure of mannose type glycans in the ER seems to be non-essential as for example in the alg3-2 mutant, where no clear phenotype can be observed (Henquet et al, 2008).…”