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Genetics in Otology and Neurotology
Published in John C Watkinson, Raymond W Clarke, Louise Jayne Clark, Adam J Donne, R James A England, Hisham M Mehanna, Gerald William McGarry, Sean Carrie, Basic Sciences Endocrine Surgery Rhinology, 2018
This is characterized by a congenital hearing loss and an elongation of the QT interval on electrocardiography. Affected individuals have episodal syncope and may have sudden death. The JLNS1 locus in the KVLQT1 gene located on chromosome 11p15.5, or the JLNS2 locus in the KCNE1 (IsK) gene located on chromosome 21q22.1-q22.2 are responsible for the syndrome. These are potassium channel genes.30
Genetics of diabetic pregnancy
Published in Moshe Hod, Lois G. Jovanovic, Gian Carlo Di Renzo, Alberto de Leiva, Oded Langer, Textbook of Diabetes and Pregnancy, 2018
Two of these genes, KCNQ1 and WFS1, are also associated with other genetic syndromes. The KCNQ1 gene encodes for a subunit of a potassium channel (KvLQT1). Mutations in the KCNQ1 gene have been implicated in long- QT syndrome, a group of disorders involving a characteristic cardiac arrhythmia. SNPs in KCNQ1 have also been shown to confer an increased risk of GDM in several different populations.57,58
Use of Biomarkers in Clinical Toxicology and Clinical Trials: A Critical Assessment of QTc Interval Prolongation as a Biomarker
Published in Anthony P. DeCaprio, Toxicologic Biomarkers, 2006
Daniel Bloomfield, John A. Wagner
The evidentiary link between a prolonged QT interval and TdP has been elegantly demonstrated in both animal and human models. When ventricular repolarization is delayed and the QT interval is prolonged, there is an increased risk of ventricular tachyarrhythmia, including TdP. Prolongation of the QT interval on the surface ECG is a reflection of prolongation of ventricular repolarization, as determined by the duration of the cardiac action potential in individual myocytes. This is a complex physiological process integrating the activities of many membrane ion channels and transporters and is affected by multiple factors including, but not limited to, intracellular and extracellular ion concentrations, membrane potential, cell-to-cell electrical coupling, heart rate, and autonomic nervous system activity. The metabolic state (e.g., acid–base balance) and location and type of cardiac cell are also important. Repolarization of the action potential is the result of the efflux of potassium via the rapidly and slowly activating components of the delayed rectifier potassium current, IKr, and IKs. The human ether-a-go-go-related gene (hERG) and KvLQT1 gene encode pore-forming proteins that are thought to represent the α-subunits of the human potassium channels responsible for IKr and IKs, respectively. The most common mechanism of QT interval prolongation by pharmaceuticals is inhibition of the delayed rectifier potassium channel that is responsible for IKr.
Clinical and genetic predictors of diabetes drug’s response
Published in Drug Metabolism Reviews, 2019
Adriana Fodor, Angela Cozma, Ramona Suharoschi, Adela Sitar-Taut, Gabriela Roman
Few studies have reported the association of KCNQ1 variants with a response to SUs in T2D. The KCNQ1 gene encodes the pore-forming subunit of a voltage-gated K + channel (KVLQT1) with a role in cardiac repolarization and probably insulin secretion in pancreatic β-cells. The KCNQ1 gene has been identified as a susceptibility locus for T2D.