Patients with glycogen storage disease (GSD) type 1b have shown normal activity of glucose-6-phosphatase (EC 3.1.3.9) as assayed in frozen liver, though their clinical and biochemical findings were similar to those of patients with GSD 1a (McKusick 23220) (Senior and Loridan, 1968).
Experimentally induced GSD-like conditions have been described in the rat (Acarbose-induced GSD II-like conditions, iodoacetate-induced symptoms of myophosphorylase (GSD V) and myophosphofructokinase (GSD VII) deficiency) and the chicken (ochratoxin A-induced symptoms of cyclic AMP-dependent protein kinase deficiency).
Experimentally induced GSD-like conditions have been described in the rat (Acarbose-induced GSD II-like conditions, iodoacetate-induced symptoms of myophosphorylase (GSD V) and myophosphofructokinase (GSD VII) deficiency) and the chicken (ochratoxin A-induced symptoms of cyclic AMP-dependent protein kinase deficiency).
The understanding of type 1 glycogen storage diseases (GSDs) has been greatly hindered by a lack of knowledge of the molecular basis of glucose-6-phosphatase (Glc-6-P'ase).
The characterization of the murine glucose-6-phosphatase gene opens the way for studying the molecular basis of GSD type 1a in humans and its etiology in an animal model.
Our results show that the G6Pase gene of GSD type 1b and 1c patients is normal, consistent with the translocase-catalytic unit model of G6Pase catalysis.
Sixteen mutations were uncovered that were shown by expression to abolish or greatly reduce G6Pase activity and that therefore are responsible for the GSD type 1a disorder.
Polymerase chain reaction (PCR) and nucleotide sequence analysis were used to identify the location and nature of mutations at the G6Pase locus in two siblings affected with type 1a GSD.
DNA analysis indicated that the fetus was a heterozygous carrier of type Ia GSD with a mutant G6Pase allele at exon 2 and a normal G6Pase allele at exon 5.
To investigate whether apolipoprotein E polymorphism modulates the susceptibility to GSD at the population level and to study the possible associations between impaired glucose tolerance, diabetes, and GSD.
Demonstration by molecular biology techniques of a mutation in both alleles of the G6Pase gene establishes the diagnosis of GSD Type Ia, obviating the need for a liver biopsy.
Comparative biochemical and histopathological evidence suggests that a deficiency in the glycogen branching enzyme, encoded by the GBE1 gene, is responsible for a recently identified recessive fatal fetal and neonatal glycogen storage disease (GSD) in American Quarter Horses termed GSD IV.
Glycogen storage diseases (GSDs) are characterized by abnormal inherited glycogen metabolism in the liver, muscle, and brain and divided into types 0 to X. GSD type I, glucose 6-phosphatase system, has types Ia, Ib, Ic, and Id, glucose 6-phosphatase, glucose 6-phosphate translocase, pyrophosphate translocase, and glucose translocase deficiencies, respectively.
Glycogen storage diseases (GSDs) are characterized by abnormal inherited glycogen metabolism in the liver, muscle, and brain and divided into types 0 to X. GSD type I, glucose 6-phosphatase system, has types Ia, Ib, Ic, and Id, glucose 6-phosphatase, glucose 6-phosphate translocase, pyrophosphate translocase, and glucose translocase deficiencies, respectively.