Search tips
Search criteria

Results 1-3 (3)

Clipboard (0)
Year of Publication
Document Types
jtitle_s:("Acta mol")
2.  A novel N440K sodium channel mutation causes myotonia with exercise-induced weakness - exclusion of CLCN1 exon deletion/duplication by MLPA 
Acta Myologica  2011;30(2):133-137.
We report a 4-generation Turkish family with 10 affected members presenting with myotonia and potassium- and exerciseinduced paralytic attacks. The clinical presentation was neither typical for the chloride channel myotonias Thomsen and Becker nor for the separate sodium channel myotonia entities potassiumaggravated myotonia, paramyotonia congenita, and hyperkalemic periodic paralysis. It is best described by a combination of potassium-aggravated myotonia and hyperkalemic periodic paralysis. We excluded exonic chloride channel mutations including CLCN1 exon deletion/duplication by MLPA. Instead we identified a novel p.N440K sodium channel mutation that is located at the inner end of segment S6 of repeat I. We discuss the genotype phenotype relation.
PMCID: PMC3235863  PMID: 22106717
chloride channel myotonia Thomsen and Becker; sodium channel myotonia; hyperkalemic periodic paralysis; potassiumaggravated myotonia; paramyotonia congenita; CLCN1; MLPA
3.  State of the art in hereditary muscle channelopathies  
Acta Myologica  2010;29(2):343-350.
A combination of electrophysiological and genetic studies has resulted in the identification of several skeletal muscle disorders to be caused by pathologically functioning ion channels and has led to the term channelopathies. Typical hereditary muscle channelopa thies are congenital myasthenic syndromes, non-dystrophic myotonias, periodic paralyses, malignant hyperthermia, and central core disease. Most muscle channelopathies are commonly considered to be benign diseases. However, lifethreatening weakness episodes or progressive permanent weakness may make these diseases severe, particularly the periodic paralyses (PP). Even in the typical PP forms characterized by episodic occurrence of weakness, up to 60% of the patients suffer from permanent weakness and myopathy with age. In addition, some PP patients present with a predominant progressive muscle weakness phenotype. The weakness can be explained by strongly depolarized fibers that take up sodium and water and that are electrically inexcitable. Drugs that repolarize the fiber membrane can restore muscle strength and may prevent progression.
PMCID: PMC3040592  PMID: 21314017
Congenital myasthenic syndromes; non-dystrophic myotonias; periodic paralyses; susceptibility to malignant hyperthermia; central core disease

Results 1-3 (3)