A Korean Family with Arg1448Cys Mutation of SCN4A Channel Causing Paramyotonia Congenita: Electrophysiologic, Histopathologic, and Molecular Genetic Studies.
10.3346/jkms.2002.17.6.856
- Author:
Dae Seong KIM
1
;
Eun Joo KIM
;
Dae Soo JUNG
;
Kyu Hyun PARK
;
In Joo KIM
;
Ki Young KWAK
;
Cheol Min KIM
;
Hyun Yoon KO
Author Information
1. Department of Neurology, College of Medicine, Pusan National University, Busan, Korea.
- Publication Type:Case Report
- Keywords:
Myotonic Disorders;
Sodium Channels
- MeSH:
Adult;
Arginine/*chemistry;
Cell Nucleus/metabolism;
Creatine Kinase/blood;
Cysteine/*chemistry;
DNA Mutational Analysis;
Exercise;
Female;
Humans;
Korea;
Male;
*Mutation, Missense;
Myotonic Disorders/*genetics;
Pedigree;
Phenotype;
Sodium Channels/*genetics/metabolism
- From:Journal of Korean Medical Science
2002;17(6):856-860
- CountryRepublic of Korea
- Language:English
-
Abstract:
A family with paramyotonia congenita (PC) is presented. At least 10 family members were affected in an autosomal dominant inheritance pattern. The proband had cold-sensitive muscle stiffness, paradoxical myotonia, and intermittent muscle weakness since childhood. The serum level of creatine kinase was mildly elevated and short exercise test with cooling revealed a drastic reduction of compound muscle action potentials with repetitive discharges. Muscle biopsy revealed marked variation in the fiber size and increased internal nuclei. The molecular biological study revealed a common missense mutation (Arg1448Cys) at the voltage-gated sodium channel gene (SCN4A). The repetitive CMAP discharges during short exercise test with cooling observed in the proband has not been reported previously. This observation needs to be confirmed among PC patients with different mutations. This is the first report on a PC family confirmed by the molecular biological technique in Korea.
