title: HyperCKemia as the only sign of McArdle's disease in a child.
abstract: An asymptomatic 13-year-old boy, who never complained of exercise intolerance or myalgia, was found to have markedly elevated serum creatine kinase (CK) levels during a routine check-up. General physical and neurologic examinations were normal. Surprisingly, histochemical and biochemical analysis of muscle showed myophosphorylase deficiency and genetic analysis showed that the patient was homozygous for the most common mutation encountered in McArdle's disease (R49X). This case illustrates the fuzzy correlation between molecular defect and clinical phenotype in patients with McArdle's disease, and suggests that a thorough study of the muscle biopsy is important in patients with idiopathic hyperCKemia for correct diagnosis and careful follow-up.
authors.affiliation: Department of Neurology, Columbia University, New York, NY, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bruno
authors.forename: E
authors.initials: E
authors.lastname: Bertini
authors.forename: F M
authors.initials: FM
authors.lastname: Santorelli
authors.forename: S
authors.initials: S
authors.lastname: DiMauro
mesh_terms: D000293:Adolescent; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D006012:Glycogen Storage Disease Type V / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D006005:Phosphorylases / Q000172:deficiency
chemical_list: D006005:Phosphorylases; D003402:Creatine Kinase