Thomsen disease with ptosis and abnormal MR findings

Neuromuscul Disord. 2016 Nov;26(11):805-808. doi: 10.1016/j.nmd.2016.08.016. Epub 2016 Sep 3.

Abstract

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.

Keywords: Autosomal dominant; Immunohistochemistry; MRI; Myotonia congenita; Skeletal muscle chloride channel-1 (CLCN1); Thomsen disease.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blepharoptosis / complications*
  • Blepharoptosis / diagnostic imaging*
  • Blepharoptosis / genetics
  • Blepharoptosis / pathology
  • Chloride Channels / genetics*
  • Chloride Channels / metabolism
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology*
  • Myotonia Congenita / complications*
  • Myotonia Congenita / diagnostic imaging*
  • Myotonia Congenita / genetics
  • Myotonia Congenita / pathology
  • Young Adult

Substances

  • CLC-1 channel
  • Chloride Channels