title: Muscle phosphorylase b kinase deficiency revisited.
abstract: Muscle phosphorylase b kinase (PHK) deficiency (glycogenosis type VIII) is a rare disorder caused by mutations in the PHKA1 gene encoding the alpha(M) subunit of PHK. Only 5 patients with molecular defects in the X-linked PHKA1 gene have been described until now, and they all presented with exercise intolerance. Here, we report a patient with a new mutation in the PHKA1 gene who presented with PHK deficiency, cognitive impairment, but no overt myopathy. This report supports the concept that PHK deficiency is a mild metabolic myopathy and suggests that PHK mutations may interfere with normal brain function.
authors.affiliation: Département de Neurologie, Hôpital Civil, BP426, 67091 Strasbourg, France. Echaniz-Laguna@medecine.u-strasbg.fr
authors.forename: Andoni
authors.initials: A
authors.lastname: Echaniz-Laguna
authors.forename: Hasan O
authors.initials: HO
authors.lastname: Akman
authors.forename: Michel
authors.initials: M
authors.lastname: Mohr
authors.forename: Christine
authors.initials: C
authors.lastname: Tranchant
authors.forename: Violaine
authors.initials: V
authors.lastname: Talmant-Verbist
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Rolland
authors.forename: Salvatore
authors.initials: S
authors.lastname: Dimauro
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence / Q000235:genetics; D001706:Biopsy; D001921:Brain / Q000201:enzymology / Q000503:physiopathology; D018389:Codon, Nonsense / Q000235:genetics; D003072:Cognition Disorders / Q000201:enzymology* / Q000235:genetics* / Q000503:physiopathology; D003402:Creatine Kinase / Q000097:blood; D004252:DNA Mutational Analysis; D004576:Electromyography; D017079:Exercise Tolerance / Q000235:genetics; D006012:Glycogen Storage Disease Type V / Q000150:complications / Q000201:enzymology* / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology; D007360:Intelligence / Q000235:genetics; D008297:Male; D018908:Muscle Weakness / Q000201:enzymology / Q000235:genetics; D018482:Muscle, Skeletal / Q000201:enzymology / Q000503:physiopathology; D010764:Phosphorylase Kinase / Q000172:deficiency* / Q000235:genetics*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism
chemical_list: D018389:Codon, Nonsense; D021122:Protein Subunits; D010764:Phosphorylase Kinase; D003402:Creatine Kinase