title: Genotype-phenotype correlation in adult-onset acid maltase deficiency.
abstract: We performed a clinical, biochemical, and genetic study in 16 patients from 11 families with adult-onset acid maltase deficiency. All patients were compound heterozygotes and carried the IVS1(-13T --> G) transversion on one allele; the second allele harbored either a deletion of a T at position 525 in exon 2 (7 probands, 64%) or a deletion of exon 18 (1 proband, 9%). Deterioration of handicap was related to age, and decrease in vital capacity to duration of the symptomatic stage. Respiratory insufficiency was never the first manifestation. The levels of activity of serum creatine kinase and of alpha-glucosidase in peripheral blood cells or muscle were helpful for the diagnosis, but did not have prognostic value. The adult form of acid maltase deficiency appears to be both clinically and genetically rather homogeneous; decrease of alpha-glucosidase activity is the final common pathway leading to destruction of muscle fibers and progression of muscle weakness over a period of years.
authors.affiliation: Rudolf Magnus Institute of the Neurosciences, Laboratory of Neuromuscular Disorders, University Utrecht, Netherlands.
authors.forename: J H
authors.initials: JH
authors.lastname: Wokke
authors.forename: M G
authors.initials: MG
authors.lastname: Ausems
authors.forename: M J
authors.initials: MJ
authors.lastname: van den Boogaard
authors.forename: E F
authors.initials: EF
authors.lastname: Ippel
authors.forename: O
authors.initials: O
authors.lastname: van Diggelene
authors.forename: M A
authors.initials: MA
authors.lastname: Kroos
authors.forename: M
authors.initials: M
authors.lastname: Boer
authors.forename: F G
authors.initials: FG
authors.lastname: Jennekens
authors.forename: A J
authors.initials: AJ
authors.lastname: Reuser
authors.forename: H K
authors.initials: HK
authors.lastname: Ploos van Amstel
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000483:Alleles; D001483:Base Sequence; D004247:DNA / Q000032:analysis; D005260:Female; D005838:Genotype; D005087:Glucan 1,4-alpha-Glucosidase / Q000172:deficiency / Q000235:genetics*; D006009:Glycogen Storage Disease Type II / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D000520:alpha-Glucosidases
chemical_list: D004247:DNA; D000520:alpha-Glucosidases; D005087:Glucan 1,4-alpha-Glucosidase