Sodium channel gene mutations in hypokalemic periodic paralysis: an uncommon cause in the UK.

Eleven of 36 families with hypokalemic periodic paralysis (hypoPP) harbored mutations in the skeletal muscle calcium channel gene (CACNA1S). The authors screened the skeletal muscle sodium channel gene (SCN4A) in the remainder. One family harbored a new heterozygous point mutation C2014A in exon 12 (R672S) of SCN4A. The authors identified the genetic defect underlying hypoPP in 33% of individuals tested. The authors conclude that SCN4A mutations are an uncommon cause of hypoPP in this UK population.