Becker muscular dystrophy or spinal muscular atrophy?--Dystrophin studies resolve conflicting results of electromyography and muscle biopsy.
We studied a 29-year-old man with slowly progressive proximal leg weakness, calf hypertrophy, and high serum levels of creatine kinase activity. Clinically, it was not possible to identify his as a sporadic instance of Becker muscular dystrophy (BMD) or one of spinal muscular atrophy. The problem arose because electromyography and elevated creatine kinase suggested a myopathy whereas changes in the muscle biopsy resembled a neurogenic disorder. The diagnosis of BMD was made by DNA analysis which detected a deletion at Xp21 and by immunoelectrophoresis and immunohistochemical tests that identified an abnormal form of gene product, dystrophin. These studies were important for genetic counselling, identifying an X-linked disease instead of one that is autosomal recessive.
McDonald
T D
TD
Department of Neurology, Columbia Presbyterian Medical Center, New York, NY 10032.
Medori
R
R
Younger
D S
DS
Chang
H W
HW
Minetti
C
C
Uncini
A
A
Bonilla
E
E
Hays
A P
AP
Lovelace
R E
RE
D000328:Adult; D015153:Blotting, Western; D004247:DNA / Q000032:analysis / Q000235:genetics; D016189:Dystrophin / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D004576:Electromyography; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007122:Immunoelectrophoresis; D007150:Immunohistochemistry; D008297:Male; D009134:Muscular Atrophy, Spinal / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009136:Muscular Dystrophies / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology
D016189:Dystrophin; D004247:DNA