Myotonia congenita (MC) is a genetic disease caused by mutations in the skeletal muscle chloride channel gene (CLCN1) encoding the skeletal muscle chloride channel (ClC-1). Mutations of CLCN1 result in either autosomal dominant MC (Thomsen disease) or autosomal recessive MC (Becker disease). The ClC-1 protein is a homodimer with a separate ion pore within each monomer. Mutations causing recessi...

Myotonic dystrophy type 2 (DM2) is caused by CCTG-repeat expansions. Occurrence of splicing and mutations in the muscle chloride channel gene CLCN1 have been reported to contribute to the phenotype. To examine the effect of CLCN1 in DM2 in Germany, we determined the frequency of a representative ClC1 mutation, R894X, and its effect on DM2 clinical features. Then, we examined CLCN1 mRNA splice v...

Myotonic dystrophy type 1 (DM1) is a genetic disorder characterized by muscle wasting, myotonia, cataracts, cardiac arrhythmia, hyperinsulinism and intellectual deficits, and is caused by expansion of a CTG repeat in the 3'UTR of the Dystrophia Myotonica-Protein Kinase (DMPK) gene. The DMPK transcripts containing expanded CUG repeats accumulate in nuclear foci and ultimately cause mis-splicing ...

Becker myotonia is a recessive muscle disease with prevalence of > 1:50,000. It is caused by markedly reduced function of the chloride channel encoded by CLCN1. We describe a Polish patient with severe myotonia, transient weakness, and muscle cramps who only responds to lidocaine. In addition, the patient has Prinzmetal angina pectoris and multiple lipomatosis. He is compound heterozygeous for ...

INTRODUCTION Myotonia Congenita is an inherited myotonia that is due to a mutation in the skeletal muscle chloride channel CLCN1. These mutations lead to reduced sarcolemmal chloride conductance, causing delayed muscle relaxation that is evident as clinical and electrical myotonia. METHODS We report the clinical presentations of two individuals with Myotonia Congenita (MC). RESULTS Patient ...

OBJECTIVE The objective of this study was to validate the immunohistochemical assay for the diagnosis of nondystrophic myotonia and to provide full clarification of clinical disease to patients in whom basic genetic testing has failed to do so. METHODS An immunohistochemical assay of sarcolemmal chloride channel abundance using 2 different ClC1-specific antibodies. RESULTS This method led t...

Myotonia congenita is a human muscle disorder caused by mutations in CLCN1, which encodes human chloride channel 1 (CLCN1). Zebrafish is becoming an increasingly useful model for human diseases, including muscle disorders. In this study, we generated transgenic zebrafish expressing, under the control of a muscle specific promoter, human CLCN1 carrying mutations that have been identified in huma...

BACKGROUND Paroxysmal kinesigenic dyskinesia (PKD) is the most common subtype of paroxysmal dyskinesias and is caused by mutations in PRRT2 gene. The majority of familial PKD was identified to harbor PRRT2 mutations. However, over two-third of sporadic PKD patients did not carry anyPRRT2 mutation, suggesting an existence of additional genetic mutations or possible misdiagnosis due to clinical o...

Myotonia congenita (MC) is a skeletal muscle channelopathy characterized by inability of the muscle to relax following voluntary contraction. Worldwide population prevalence in humans is 1:100,000. Studies in mice, dogs, humans and goats confirmed myotonia associated with functional defects in chloride channels and mutations in a skeletal muscle chloride channel (CLCN1). CLCN1 encodes for the m...