This report describes long QT syndrome 1 (LQT1), a subtype of long QT syndrome; LQT1 exhibits autosomal dominant inheritance. The human gene implicated in this disease is KCNQ1, which encodes potassium voltage-gated channel subfamily Q member 1, a voltage-gated potassium channel required for repolarization phase of the cardiac action potential; there are multiple members of this family in human. There is one fly gene, Dmel\KCNQ, that is orthologous to KCNQ1, as well as to the other members of the "subfamily Q" potassium voltage-gated channel genes in human. Information about fly models for this and related diseases can be found in the report 'cardiac arrhythmias, KCNQ-related' (FBhh0000733).
[updated Feb. 2018 by FlyBase; FBrf0222196]
Long QT syndrome (LQTS) is a cardiac electrophysiologic disorder, characterized by QT prolongation and T-wave abnormalities on the ECG and the ventricular tachycardia torsade de pointes (TdP). TdP is usually self-terminating, thus causing a syncopal event, the most common symptom in individuals with LQTS. Syncope typically occurs during exercise and high emotions, less frequently at rest or during sleep, and usually without warning. In some instances, TdP degenerates to ventricular fibrillation and causes aborted cardiac arrest (if the individual is defibrillated) or sudden death. Approximately 50% of individuals with a pathogenic variant in one of the genes associated with LQTS have symptoms, usually one to a few syncopal spells. While cardiac events may occur from infancy through middle age, they are most common from the pre-teen years through the 20s. Some types of LQTS are associated with a phenotype extending beyond cardiac arrhythmia. In addition to the prolonged QT interval, associations include muscle weakness and facial dysmorphism in Andersen-Tawil syndrome (LQTS type 7, MIM:170390), hand/foot, facial, and neurodevelopmental features in Timothy syndrome (LQTS type 8, MIM:601005) and profound sensorineural hearing loss in Jervell and Lange-Nielson syndrome (MIM:220400, MIM:612347). [from GeneReviews, Long QT Syndrome, pubmed:20301308 2016.06.07]
Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death (Jongbloed et al., 1999, pubmed:10220144). [From MIM:192500, 2016.06.07]
[LONG QT SYNDROME 1; LQT1](https://omim.org/entry/192500)
[POTASSIUM CHANNEL, VOLTAGE-GATED, KQT-LIKE SUBFAMILY, MEMBER 1; KCNQ1](https://omim.org/entry/607542)
Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death (Jongbloed et al., 1999, pubmed:10220144). [From MIM:192500, 2016.06.07]
Long QT syndrome-1 (LQT1) is caused by heterozygous mutation in KCNQ1, the gene encoding the KQT-like voltage-gated potassium channel-1. [From MIM:192500, 2016.06.07]
KCNQ1 encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. [provided by RefSeq, Aug 2011]
Many to one: 5 human to 1 Drosophila.