Abstract | BACKGROUND AND PURPOSE: METHODS: Six unrelated Korean patients with periodic paralysis or nondystrophic myotonia associated with SCN4A mutations were included in the study. For the mutational analysis of SCN4A, we performed a full sequence analysis of the gene using the patients' DNA. We also analyzed the patients' clinical history, physical findings, laboratory tests, and responses to treatment. RESULTS: We identified four different mutations (one of which was novel) in all of the patients examined. The novel heterozygous missense mutation, p.R225W, was found in one patient with mild nonpainful myotonia. Our patients exhibited various clinical phenotypes: pure myotonia in four, and PMC in one, and HYPP in one. The four patients with pure myotonia were initially diagnosed as having myotonia congenita (MC), but a previous analysis revealed no CLCN1 mutation. CONCLUSIONS: Clinical differentiating between sodium-channel myotonia (SCM) and MC is not easy, and it is suggested that a mutational analysis of both SCN4A and CLCN1 is essential for the differential diagnosis of SCM and MC.
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Authors | Sang-Chan Lee, Hyang-Sook Kim, Yeong-Eun Park, Young-Chul Choi, Kyu-Hyun Park, Dae-Seong Kim |
Journal | Journal of clinical neurology (Seoul, Korea)
(J Clin Neurol)
Vol. 5
Issue 4
Pg. 186-91
(Dec 2009)
ISSN: 2005-5013 [Electronic] Korea (South) |
PMID | 20076800
(Publication Type: Journal Article)
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