Carbohydrate-deficient glycoprotein syndrome is group of disorders that present in infancy with failure to thrive, multiple organ system involvement and severe neurologic manifestations. The underlying metabolic defects are in the multi-step, complex synthesis of N-linked oligosaccharides, distinct multisugar structures that have important biologic functions. One enzyme, phosphomannomutase, has been hypothesized to be deficient for some CDGS patients. The biochemical characterization of phosphomannomutase (PMM) via the development of a new enzyme assay has elucidated the complexity of this particular metabolic defect. Molecular biologic techniques have revealed that American CDGS patients have both previously reported and novel base changes. The reported gene and its surrounding sequence is being analyzed. The remarkable clinical heterogeneity of the American CDGS population is being studied. Two American Type 4 CDGS patients have recently been identified, which doubles the world population. Biochemical studies on skin fibroblasts and lymphoblasts from these patients are being used to explore the synthesis of N-linked oligosaccharides in these Type 4 children. The clinical, molecular and biochemical characterization of CDGS provides insight into the important role of N-linked oligosaccharides in human physiology.

Agency
National Institute of Health (NIH)
Institute
National Human Genome Research Institute (NHGRI)
Type
Intramural Research (Z01)
Project #
1Z01HG000100-01
Application #
6162607
Study Section
Molecular Genetics B Study Section (MGB)
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
1997
Total Cost
Indirect Cost
Name
National Human Genome Research Institute
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Huizing, Marjan; Krasnewich, Donna M (2009) Hereditary inclusion body myopathy: a decade of progress. Biochim Biophys Acta 1792:881-7
Galeano, Belinda; Klootwijk, Riko; Manoli, Irini et al. (2007) Mutation in the key enzyme of sialic acid biosynthesis causes severe glomerular proteinuria and is rescued by N-acetylmannosamine. J Clin Invest 117:1585-94
Krasnewich, Donna; O'Brien, Kevin; Sparks, Susan (2007) Clinical features in adults with congenital disorders of glycosylation type Ia (CDG-Ia). Am J Med Genet C Semin Med Genet 145C:302-6
Sparks, Susan; Rakocevic, Goran; Joe, Galen et al. (2007) Intravenous immune globulin in hereditary inclusion body myopathy: a pilot study. BMC Neurol 7:3
Kranz, Christian; Sun, Liangwu; Eklund, Erik A et al. (2007) CDG-Id in two siblings with partially different phenotypes. Am J Med Genet A 143A:1414-20
Ries, Markus; Moore, David F; Robinson, Chevalia J et al. (2006) Quantitative dysmorphology assessment in Fabry disease. Genet Med 8:96-101
Savelkoul, Paul J M; Manoli, Irini; Sparks, Susan E et al. (2006) Normal sialylation of serum N-linked and O-GalNAc-linked glycans in hereditary inclusion-body myopathy. Mol Genet Metab 88:389-90
Sparks, Susan E; Ciccone, Carla; Lalor, Molly et al. (2005) Use of a cell-free system to determine UDP-N-acetylglucosamine 2-epimerase and N-acetylmannosamine kinase activities in human hereditary inclusion body myopathy. Glycobiology 15:1102-10
Huizing, Marjan; Rakocevic, Goran; Sparks, Susan E et al. (2004) Hypoglycosylation of alpha-dystroglycan in patients with hereditary IBM due to GNE mutations. Mol Genet Metab 81:196-202
Orvisky, E; Stubblefield, B; Long, R T et al. (2003) Phosphomannomutase activity in congenital disorders of glycosylation type Ia determined by direct analysis of the interconversion of mannose-1-phosphate to mannose-6-phosphate by high-pH anion-exchange chromatography with pulsed amperometric detection. Anal Biochem 317:12-8

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