A 2-bp deletion in exon 74 of the dystrophin gene does not clearly induce muscle weakness.
Duchenne muscular dystrophy (DMD) is caused by mutation of the dystrophin gene. Cases of dystrophinopathy with a 2-bp deletion in the dystrophin gene commonly result in DMD. We report here a case of dystrophinopathy in a 9-years-old boy with a 2-bp deletion in exon 74 of the dystrophin gene; however, the boy had no clear clinical signs of muscle weakness. Immunohistochemical studies with N-terminal (DYS3) and rod-domain anti-dystrophin (DYS1) antibodies revealed that the dystrophin signals were weaker than in the control sample (non-dystrophinopathy) at the sarcolemma of myofibers, and the studies with C-terminus anti-dystrophin antibody (DYS2) were negative. Our patient's mutation is located between the binding sites of alpha-syntrophin and alpha-dystrobrevin. These results suggest that this mutation does not clearly induce muscle weakness at least through the age of 9 years.
Kimura
Shigemi
S
Department of Child Development, Kumamoto University Graduate School, 1-1-1 Honjou, Kumamoto 860-0811, Japan. kimusige@kumamoto-u.ac.jp
Ito
Kaori
K
Ueno
Hiroe
H
Ikezawa
Makoto
M
Takeshima
Yasuhiro
Y
Yoshioka
Kowashi
K
Ozasa
Shiro
S
Nakamura
Kyoko
K
Nomura
Keiko
K
Matsukura
Makoto
M
Mitsui
Koichi
K
Matsuo
Masafumi
M
Miike
Teruhisa
T
D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002648:Child; D016189:Dystrophin / Q000235:genetics* / Q000378:metabolism; D049029:Dystrophin-Associated Proteins / Q000378:metabolism; D005091:Exons; D005796:Genes; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D018908:Muscle Weakness / Q000235:genetics* / Q000503:physiopathology; D012508:Sarcolemma / Q000378:metabolism; D017384:Sequence Deletion
D002135:Calcium-Binding Proteins; D016189:Dystrophin; D049029:Dystrophin-Associated Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; C098885:dystrobrevin; C091825:syntrophin alpha1