Abstract
Mutations in the skeletal muscle voltage-gated sodium channel α- subunit gene (SCN4A) have been associated with a spectrum of inherited nondystrophic myotonias and periodic paralyses. Most disease-associated SCN4A alleles occur in portions of the gene that encode the third and fourth repeat domains with the conspicuous absence of mutations in domain 1. Here we describe a family segregating an unusual autosomal dominant congenital myotonia associated with debilitating pain especially severe in the intercostal muscles. A novel SCN4A mutation causing the replacement of Val445 in the sixth transmembrane segment of domain 1 with methionine was discovered in all affected individuals and is the likely genetic basis for the syndrome. Myotonia was resistant to treatment; however, the most severely affected family member responded dramatically to the sodium channel blocking agent flecainide.
Original language | English (US) |
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Pages (from-to) | 811-814 |
Number of pages | 4 |
Journal | Annals of neurology |
Volume | 42 |
Issue number | 5 |
DOIs | |
State | Published - Nov 1997 |
ASJC Scopus subject areas
- Clinical Neurology
- Neurology