Dysferlin mutations in Japanese Miyoshi myopathy: relationship to phenotype.
OBJECTIVE
To study dysferlin gene mutations and genotype-phenotype correlations in Japanese patients with Miyoshi myopathy (MM).


BACKGROUND
MM is an autosomal recessive distal muscular dystrophy that arises from mutations in the dysferlin gene. This gene is also mutated in families with limb girdle muscular dystrophy 2B.


METHODS
The authors examined 25 Japanese patients with MM. Genomic DNA was extracted from the peripheral lymphocytes of the patients. The PCR products of each of 55 exons were screened by single strand conformation polymorphism or direct sequencing from the PCR fragments.


RESULTS
The authors identified 16 different mutations in 20 patients with MM; 10 were novel. Mutations in Japanese patients are distributed along the entire length of the gene.


CONCLUSIONS
Four mutations (C1939G, G3370T, 3746delG, and 4870delT) are relatively more prevalent in this population, accounting for 60% of the mutations in this study. This study revealed that the G3370T mutation was associated with milder forms of MM and the G3510A mutation was associated with a more severe form.
Takahashi
T
T
Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
Aoki
M
M
Tateyama
M
M
Kondo
E
E
Mizuno
T
T
Onodera
Y
Y
Takano
R
R
Kawai
H
H
Kamakura
K
K
Mochizuki
H
H
Shizuka-Ikeda
M
M
Nakagawa
M
M
Yoshida
Y
Y
Akanuma
J
J
Hoshino
K
K
Saito
H
H
Nishizawa
M
M
Kato
S
S
Saito
K
K
Miyachi
T
T
Yamashita
H
H
Kawai
M
M
Matsumura
T
T
Kuzuhara
S
S
Ibi
T
T
Sahashi
K
K
Nakai
H
H
Kohnosu
T
T
Nonaka
I
I
Arahata
K
K
Brown
R H
RH
Saito
H
H
Itoyama
Y
Y
D000328:Adult; D003402:Creatine Kinase / Q000097:blood; D004252:DNA Mutational Analysis; D000073939:Dysferlin; D005260:Female; D005838:Genotype; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D009136:Muscular Dystrophies / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D011110:Polymorphism, Genetic
C114839:DYSF protein, human; D000073939:Dysferlin; D008565:Membrane Proteins; D009124:Muscle Proteins; D003402:Creatine Kinase