title: Pseudometabolic presentation of dystrophinopathy due to a missense mutation.
abstract: Exercise intolerance with myalgia, muscle stiffness, and recurrent rhabdomyolysis due to mutations in the DMD gene can mimic metabolic myopathies leading to delayed or inaccurate diagnoses. In this retrospective chart review, we report 3 unrelated boys with exertional myalgia, muscle stiffness, myoglobinuria, and normal neurological examination due to an identical point mutation in the DMD gene: a hemizygous T-to-C change in exon 15 (c.1724T>C) resulting in an amino acid substitution of leucine to proline at codon 575. Two of the 3 boys had normal dystrophin immunostaining and Western blot analysis in muscle. This missense mutation has been reported twice before, with at least 1 patient exhibiting rhabdomyolysis. Our report, however, is the first to describe in detail the clinical findings associated with this specific mutation. Further studies and clinical reports are needed to better understand the pathogenicity of the mutation.
authors.affiliation: Swami Clinic, Jayam Diabetic Center, Nalladai Road, Sembanarkoil, Nagai Dt., Tamilnadu 609309, India.
authors.forename: Aravindhan
authors.initials: A
authors.lastname: Veerapandiyan
authors.forename: Vandana
authors.initials: V
authors.lastname: Shashi
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Jiang
authors.forename: William Brian
authors.initials: WB
authors.lastname: Gallentine
authors.forename: Kelly
authors.initials: K
authors.lastname: Schoch
authors.forename: Edward Clinton
authors.initials: EC
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D002648:Child; D016189:Dystrophin / Q000235:genetics* / Q000378:metabolism; D015444:Exercise; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology*; D009135:Muscular Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D020125:Mutation, Missense; D009212:Myoglobinuria / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
chemical_list: C484258:DMD protein, human; D016189:Dystrophin