title: Human muscle glycogenosis due to phosphorylase kinase deficiency associated with a nonsense mutation in the muscle isoform of the alpha subunit.
abstract: Heritable phosphorylase kinase (Phk) deficiency is responsible for several forms of glycogen storage disease in humans and animals that differ in mode of inheritance and tissue-specificity. Mutations affecting different subunits and isoforms of Phk are expected to contribute to this heterogeneity. In the present study, we have investigated a case of muscle-specific, adult-onset Phk deficiency. The coding sequences of three candidate genes were analyzed by RT-PCR and sequencing: the muscle isoform of the alpha subunit (alpha M), a muscle-specifically expressed exon of the beta subunit, and the muscle isoform of the gamma subunit. Whereas the latter two sequences were found to be normal, we identified a nonsense mutation in alpha M. The condition of this patient therefore is a human homolog of the X-linked muscle Phk deficiency of I-strain mice. To our knowledge, this is the first description of a human Phk deficiency mutation.
authors.affiliation: Institut für Physiologische Chemie, Ruhr-Universität Bochum, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Wehner
authors.forename: P R
authors.initials: PR
authors.lastname: Clemens
authors.forename: A G
authors.initials: AG
authors.lastname: Engel
authors.forename: M W
authors.initials: MW
authors.lastname: Kilimann
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018740:Genetic Heterogeneity; D006008:Glycogen Storage Disease / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009135:Muscular Diseases / Q000201:enzymology / Q000235:genetics*; D010764:Phosphorylase Kinase / Q000172:deficiency* / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction
chemical_list: D007527:Isoenzymes; D010764:Phosphorylase Kinase