Thomsen disease with ptosis and abnormal MR findings.
Myotonia congenita is a non-dystrophic skeletal muscle disorder characterized by muscle stiffness and an inability of the muscle to relax after voluntary contraction caused by a mutation in the gene encoding skeletal muscle chloride channel-1 (CLCN1). We encountered a case of Thomsen disease with ptosis. A short tau inversion recovery MR imaging demonstrated high-intensity lesions in the levator palpebrae superioris muscles. Molecular genetic testing revealed a heterozygosity for the c.1439C>A (p.P480H) mutation in the CLCN1 gene. The expression level of ClC-1 was significantly reduced on the sarcolemma of the biceps brachii muscle from the patient, compared with that from healthy volunteer. Functional analysis of the p.P480H mutation is required for further elucidating the pathogenesis of Thomsen disease.
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Yukiko
Y
Mori
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan. Electronic address: y-stsh@kumamoto-u.ac.jp.
Satoshi
S
Yamashita
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Mai
M
Kato
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Teruaki
T
Masuda
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Koutaro
K
Takamatsu
Department of Nursing, Kyushu University of Nursing and Social Welfare, 888 Tomio, Tamana 865-0062, Japan.
Toshihide
T
Kumamoto
Department of Neurology, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu 514-8507, Japan.
Ryogen
R
Sasaki
Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Yukio
Y
Ando
D001763:Blepharoptosis / Q000150:complications* / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology; D018118:Chloride Channels / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology*; D009224:Myotonia Congenita / Q000150:complications* / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology; D055815:Young Adult
C086321:CLC-1 channel; D018118:Chloride Channels
Autosomal dominant; Immunohistochemistry; MRI; Myotonia congenita; Skeletal muscle chloride channel-1 (CLCN1); Thomsen disease