KCNQ1 mutations associated with Jervell and Lange-Nielsen syndrome and autosomal recessive Romano-Ward syndrome in India-expanding the spectrum of long QT syndrome type 1.
Although L1825P generates late sodium current typical of SCN5A-linked long-QT syndrome (LQT3) in vitro, the patient reported had a normal QT interval before administration of the drug.
One form of hereditary long QT (LQT3) has been linked to a mutation in the gene encoding the human heart voltage-gated sodium-channel alpha-subunit (SCN5A on chromosome 3p21).
Ranolazine reduces late sodium channel current, and we hypothesized that ranolazine would have beneficial effects on electrical and mechanical cardiac function in LQT3 patients with the SCN5A-DeltaKPQ mutation.
The SCN5A mutations have been associated with a variety of arrhythmic disorders, including type 3 long QT syndrome (LQT3), Brugada syndrome and inherited cardiac conduction defects.
Mutations in the SCN5A gene have been linked to Brugada syndrome (BrS), conduction disease, Long QT syndrome (LQT3), atrial fibrillation (AF), and to pre- and neonatal ventricular arrhythmias.
The objective of the current study was to evaluate the long-term safety and efficacy of flecainide therapy in patients with LQT3 who carry the D1790GSCN5A mutation.
The purpose of this study was to describe the first family associating LQT-3 and AF due to a gain-of-function mutation in SCN5A and assess the usefulness of the sodium blocker flecainide in individuals with both phenotypes.