Undetectable dystrophin can still result in a relatively benign phenotype of dystrophinopathy.
We present here a 28-year-old male patient with Becker muscular dystrophy whose skeletal muscle showed an absence of dystrophin. He has had progressive and predominantly proximal muscular wasting since 5 years of age, but was able to walk until 26 years of age. He showed hypertrophic calves, cardiomyopathy, and an elevated serum creatine kinase level (934 U/1). A skeletal muscle biopsy revealed advanced chronic myopathic changes. Immunohistochemical examination using anti-dystrophin antibodies against C-terminus showed deficiency of the protein. Rod domain and N-terminus were also absent in almost all muscle fibers, but only in a small part of the sample, they were faintly stained. beta-Dystroglycan and utrophin were present only in a small number of muscle fibers. DNA and RT-PCR analysis showed a frame-shift deletion of exons 3-7 in the dystrophin gene. In such an exceptional case as this one, it is important to investigate the factors which determine the severity of dystrophinopathy.
Hattori
N
N
Department of Neurology, Osaka Prefectural General Hospital, Japan.
Kaido
M
M
Nishigaki
T
T
Inui
K
K
Fujimura
H
H
Nishimura
T
T
Naka
T
T
Hazama
T
T
D000328:Adult; D015153:Blotting, Western; D004247:DNA / Q000032:analysis / Q000235:genetics; D016189:Dystrophin / Q000737:chemistry* / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018908:Muscle Weakness / Q000209:etiology / Q000235:genetics / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009136:Muscular Dystrophies / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016189:Dystrophin; D004247:DNA