Referenced in: none

Automatically associated channels: Nav1.4

Title: Paralysis periodica paramyotonica caused by SCN4A Arg1448Cys mutation.

Authors: Wei-Chih Hsu, Yung-Chuan Huang, Chung-Wei Wang, Chia-Hsiang Hsueh, Ling-Ping Lai, Jiann-Horng Yeh

Journal, date & volume: J. Formos. Med. Assoc., 2006 Jun , 105, 503-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16801039

Abstract
Paralysis periodica paramyotonica is an overlapping disease that shares the features of paramyotonia characteristic of paramyotonia congenita (PC) and periodic paralysis characteristic of hyperkalemic periodic paralysis. We report the case of a 23-year-old man with paralysis periodica paramyotonica. His father and a younger brother also exhibited a similar phenotype. A SCN4A Arg1448Cys mutation was detected in this family. The affected family members exhibited marked shifts in compound muscle action potential amplitudes on exercise test, and muscle weakness could be induced by potassium loading and cold exposure. This case demonstrates that SCN4A Arg1448Cys can produce paralysis periodica paramyotonica. Other genetic or environmental factors may modulate the manifestation of SCN4A Arg1448Cys mutation.