Gene:
sodium channel, voltage-gated, type V, alpha (long QT syndrome 3)
Description:
The protein encoded by this gene is an integral membrane protein and tetrodotoxin-resistant voltage-gated sodium channel subunit. The encoded protein is found primarily in cardiac muscle and is responsible for the initial upstroke of the action potential in an electrocardiogram. Defects in this gene are a cause of long QT syndrome type 3 (LQT3), an autosomal dominant cardiac disease. Alternative splicing results in two transcript variants encoding separate isoforms which differ by a single amino acid. Mutation nomenclature has been assigned with respect to the longer isoform.