title: Homozygous deletion of exon 18 leads to degradation of the lysosomal alpha-glucosidase precursor and to the infantile form of glycogen storage disease type II.
abstract: We describe two unrelated Dutch patients with typical symptoms of infantile glycogen storage disease type II (GSD II) and virtual absence of acid alpha-glucosidase activity in leukocytes and cultured skin fibroblasts. The patients were identified as homozygotes for a deletion of exon 18 of the acid alpha-glucosidase gene (GAA). The in-frame deletion manifests at the protein level in a characteristic way: the enzyme precursor is smaller than normal and degraded in the endoplasmic reticulum or Golgi complex. These case present an evident example of a genotype-phenotype correlation in glycogen storage disease type II.
authors.affiliation: Clinical Genetics Centre Utrecht, The Netherlands.
authors.forename: M G
authors.initials: MG
authors.lastname: Ausems
authors.forename: M A
authors.initials: MA
authors.lastname: Kroos
authors.forename: M
authors.initials: M
authors.lastname: Van der Kraan
authors.forename: J A
authors.initials: JA
authors.lastname: Smeitink
authors.forename: W J
authors.initials: WJ
authors.lastname: Kleijer
authors.forename: H K
authors.initials: HK
authors.lastname: Ploos van Amstel
authors.forename: A J
authors.initials: AJ
authors.lastname: Reuser
mesh_terms: D002872:Chromosome Deletion; D004792:Enzyme Precursors / Q000378:metabolism*; D005091:Exons; D006009:Glycogen Storage Disease Type II / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D008247:Lysosomes / Q000201:enzymology*; D008297:Male; D010375:Pedigree; D000520:alpha-Glucosidases / Q000172:deficiency* / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D000520:alpha-Glucosidases