We generated human induced pluripotent stem cells (hiPSCs) from a symptomatic Long QT Syndrome (LQTS) type 1 patient, belonging to a South African (SA) founder population segregating the heterozygous mutation c.1022C > T p.A341V on the KCNQ1 gene.
We generated PSMi001-A and PSMi008-A hiPSC lines from two individuals belonging to a South African (SA) founder population in which the malignant KCNQ1-A341V mutation cosegregates with the Long QT Syndrome (LQTS) phenotype.
This study tested the hypothesis that vagal and sympathetic control, as assessed by spectral analysis of spontaneous beat-to-beat variability of RR and QT intervals from standard 24-h electrocardiogram Holter recordings, could modulate the severity of LQTS type 1 (LQT1) in 46 members of a South-African LQT1 founder population carrying the clinically severe KCNQ1 A341V mutation.
We studied 169 LQTS genotype-positive patients < 50 years of age who performed an ExStrT with the same protocol, on and off β-blockers including 47 South African LQT1 patients all harboring the KCNQ1-A341V mutation and 122 Italian LQTS patients with impaired (I(Ks)-, 66 LQT1) or normal (I(Ks)+, 50 LQT2 and 6 LQT3) I(Ks) current.
In a South African (SA) founder population, we identified a common LQTS type 1 (LQT1)-causing mutation (KCNQ1-A341V) associated with high clinical severity.
The common long-QT syndrome mutation KCNQ1/A341V causes unusually severe clinical manifestations in patients with different ethnic backgrounds: toward a mutation-specific risk stratification.
One of the most common and potentially life-threatening electrolyte disturbances is hypokalemia, characterized by low concentrations of K<sup>+</sup> Using a multielectrode array platform and current clamp technique, we investigated the effect of low extracellular K<sup>+</sup> concentration ([K<sup>+</sup>]<sub>Ex</sub>) on the electrophysiological properties of hiPSC-derived cardiomyocytes (CMs) generated from a healthy control subject (WT) and from two symptomatic patients with type 1 of LQTS carrying G589D (LQT1A) or IVS7-2A>G mutation (LQT1B) in <i>KCNQ1</i> The baseline prolongations of field potential durations (FPDs) and action potential durations (APDs) were longer in LQT1-CMs than in WT-CMs.
One of the most common and potentially life-threatening electrolyte disturbances is hypokalemia, characterized by low concentrations of K<sup>+</sup> Using a multielectrode array platform and current clamp technique, we investigated the effect of low extracellular K<sup>+</sup> concentration ([K<sup>+</sup>]<sub>Ex</sub>) on the electrophysiological properties of hiPSC-derived cardiomyocytes (CMs) generated from a healthy control subject (WT) and from two symptomatic patients with type 1 of LQTS carrying G589D (LQT1A) or IVS7-2A>G mutation (LQT1B) in <i>KCNQ1</i> The baseline prolongations of field potential durations (FPDs) and action potential durations (APDs) were longer in LQT1-CMs than in WT-CMs.
We examined the role of a novel synonymous <i>KCNQ1</i> p.L353L variant on the splicing of exon 8 and on heart rate corrected QT interval (QTc) in a population known to have a pathogenic LQTS type 1 (LQTS1) causative mutation, p.V205M, in <i>KCNQ1</i>-encoded Kv7.1.