An Arg528His Mutation of the CACNL1A3 Gene in a Korean Family with Hypokalemic Periodic Paralysis

Abstract

Familial hypokalemic periodic paralysis (HOPP) is an autosomal dominant disorder characterized by episodic attacks of muscle weakness with concomitant hypokalemia (<3.5 mEq/L). The onset of HOPP usually occurs within the first and second decade of life. Mutations in the skeletal muscle calcium (CACNL1A3 ) and sodium channel (SCN4A) genes have been reported to be responsible for familial HOPP. Voltage-sensitive ion channels mediate action potentials in electrically excitable cells and play important roles in signal transduction in other cell types. Therefore, abnormalities in a channel's function lead to disarray of signal transduction and thus various neurological symptoms. Those are called channel diseases, which include familial HOPP. We report a 14-year-old boy with HOPP from a family in which two members of two generations are affected. Genetic examination identified a mutation causing a codon change from arginine to histidine at the amino acid portion #528 (R528H) in the calcium channel gene CACNL1A3.