Abnormal synthesis of mannose 1-phosphate derived carbohydrates in carbohydrate-deficient glycoprotein syndrome type I fibroblasts with phosphomannomutase deficiency

Glycobiology. 1998 Feb;8(2):165-71. doi: 10.1093/glycob/8.2.165.


In fibroblasts from five patients with carbohydrate-deficient glycoprotein syndrome type 1, the incorporation of [2-3H] mannose into mannose phosphates, GDP-mannose, GDP-fucose, dolichol-P-mannose, lipid-linked oligosaccharides, and glycoprotein fraction was determined. We observed a 3- to 5-fold reduction of incorporation of radioactivity into mannose 1-phosphate, GDP-mannose, GDP-fucose, dolichol-P-mannose, and nascent glycoproteins. The incorporation of radioactivity into mannose 6-phosphate was normal. The formation of lipid linked oligosaccharides was only slightly affected (</=20%), but their size was severely reduced, mostly containing five or fewer residues. As a consequence, truncated oligosaccharides were transferred to newly synthesized glycoproteins. The metabolic changes can be explained by a deficiency of phosphomannomutase activity, which was reduced to </=10% of control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrates / biosynthesis*
  • Carbohydrates / deficiency
  • Cells, Cultured
  • Congenital Disorders of Glycosylation / enzymology*
  • Congenital Disorders of Glycosylation / metabolism*
  • Congenital Disorders of Glycosylation / pathology
  • Dolichol Monophosphate Mannose / metabolism
  • Fibroblasts / enzymology
  • Fibroblasts / metabolism
  • Guanosine Diphosphate Fucose / biosynthesis
  • Guanosine Diphosphate Mannose / biosynthesis
  • Humans
  • Lipopolysaccharides / biosynthesis
  • Mannosephosphates / biosynthesis
  • Mannosephosphates / metabolism*
  • Phosphotransferases (Phosphomutases) / deficiency*


  • Carbohydrates
  • Lipopolysaccharides
  • Mannosephosphates
  • lipid-linked oligosaccharides
  • Guanosine Diphosphate Fucose
  • mannose 1-phosphate
  • Guanosine Diphosphate Mannose
  • Dolichol Monophosphate Mannose
  • Phosphotransferases (Phosphomutases)
  • phosphomannomutase