Hyperkalemic Periodic Paralysis and the Adult Muscle Sodium Channel α-Subunit Gene

TLDR

Hyperkalemic periodic paralysis is an autosomal dominant disorder causing episodic muscle weakness from depolarization linked to high serum potassium, and electrophysiological studies implicate the adult muscle sodium channel. Portions of the adult muscle sodium channel α‑subunit gene were cloned and mapped near the GH1 locus on chromosome 17. In a large pedigree with HYPP and myotonia, the sodium channel α‑subunit gene and GH1 locus showed tight linkage with no recombinants, indicating the mutation lies in the sodium channel gene.

Abstract

Hyperkalemic periodic paralysis (HYPP) is an autosomal dominant disorder characterized by episodes of muscle weakness due to depolarization of the muscle cell membrane associated with elevated serum potassium. Electrophysiological studies have implicated the adult muscle sodium channel. Here, portions of the adult muscle sodium channel α-subunit gene were cloned and mapped near the human growth hormone locus ( GH1 ) on chromosome 17. In a large pedigree displaying HYPP with myotonia, these two loci showed tight linkage to the genetic defect with no recombinants detected. Thus, it is likely that the sodium channel α-subunit gene contains the HYPP mutation.