Hypokalaemic periodic paralysis and myotonia in a patient with homozygous mutation p.R1451L in Na_V1.4.

ABSTRACT: Dominantly inherited channelopathies of the skeletal muscle voltage-gated sodium channel Na_V1.4 include hypokalaemic and hyperkalaemic periodic paralysis (hypoPP and hyperPP) and myotonia. HyperPP and myotonia are caused by Na_V1.4 channel overactivity and overlap clinically. Instead, hypoPP is caused by gating pore currents through the voltage sensing domains (VSDs) of Na_V1.4 and seldom co-exists clinically with myotonia. Recessive loss-of-function Na_V1.4 mutations have been described in congenital myopathy and myasthenic syndromes. We report two families with the Na_V1.4 mutation p.R1451L, located in VSD-IV. Heterozygous carriers in both families manifest with myotonia and/or hyperPP. In contrast, a homozygous case presents with both h

SUBMITTER: Luo S 

PROVIDER: S-EPMC6018793 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature