title: Follow-up of three patients with a large in-frame deletion of exons 45-55 in the Duchenne muscular dystrophy (DMD) gene.
abstract: We review the clinical status of skeletal involvement and cardiac function in three unrelated patients harboring an in-frame deletion of exons 45 to 55 in the DMD gene followed up for 2 to 7 years. Two younger patients diagnosed as having X-linked dilated cardiomyopathy (XLDCM) developed congestive heart failure without overt skeletal myopathy. Heart failure recurred after viral infection but responded well to diuretics and angiotensin-converting enzyme inhibitors. One older patient diagnosed with Becker muscular dystrophy showed limb-girdle muscular atrophy and weakness at the age of 50, but did not have any cardiac symptoms. Skeletal muscle involvement in each patient remained unchanged, and cardiac function did not worsen in any of the patients during the study. In a younger XLDCM patient, the amount and molecular weight of mutant dystrophin were equally slightly decreased in both skeletal and cardiac muscles. Immunostaining for dystrophin and dystrophin-associated proteins was slightly reduced in both skeletal and cardiac muscle, with no discernible difference between the two. The phenotype of this dystrophinopathy can manifest as XLDCM in younger patients; however, careful attention to cardiac management may result in a favorable prognosis.
authors.affiliation: Department of Neurology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan. anakamu@ncnp.go.jp
authors.forename: Akinori
authors.initials: A
authors.lastname: Nakamura
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Hideho
authors.initials: H
authors.lastname: Ueda
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Urasawa
authors.forename: Jun
authors.initials: J
authors.lastname: Koyama
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yazaki
authors.forename: Masahide
authors.initials: M
authors.lastname: Yazaki
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Sakai
authors.forename: Seiichi
authors.initials: S
authors.lastname: Haruta
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Takeda
authors.forename: Shu-Ichi
authors.initials: S
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D018450:Disease Progression; D016189:Dystrophin / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005500:Follow-Up Studies; D017353:Gene Deletion; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009136:Muscular Dystrophies / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D010641:Phenotype
chemical_list: C484258:DMD protein, human; D016189:Dystrophin; D005819:Genetic Markers