Eighteen German families with a history of paramyotonia congenita (PC) were characterised by genetic and mutational analysis at the SCN4A locus, which encodes the alpha-subunit of the adult skeletal muscle sodium channel.
The inherited diseases hyperkalemic periodic paralysis and paramyotonia congenita are caused by mutations in the adult skeletal muscle sodium channel gene.
We tested the hypothesis that hyperkalemic periodic paralysis (without myotonia) and paramyotonia congenita are tightly linked to the tetrodotoxin-sensitive adult skeletal muscle sodium channel gene on chromosome 17q23-25 in two large pedigrees.