Association between HERG K897T polymorphism and QT interval in middle-aged Finnish women.
OBJECTIVE
The aim of this study was to test whether a recently reported polymorphism in the HERG gene coding for the rapidly activating delayed rectifier K+ channel has influence on myocardial repolarization.


BACKGROUND
The length of myocardial repolarization, measured as the QT interval, has a hereditary component, but no genes that would explain the variability of repolarization have been identified in healthy subjects.


METHODS
QT intervals were measured from the 12-lead electrocardiogram in a random middle-aged population (226 men/187 women). The longest QT interval at any of the 12 leads (QTmax), QTV(2), and the Tpeak-Tend interval were used as measures of repolarization. Deoxyribonucleic acid samples were genotyped for the nucleotide 2690A>C variation of the HERG gene, corresponding to the HERG K(lysine)897T(threonine) amino acid polymorphism.


RESULTS
The allele frequencies were 0.84 (A) and 0.16 (C). Females with the genotype AC or CC had longer QTcmax (477 +/- 99 ms) and Tpeak-Tend intervals (143 +/- 95 ms) than females with the genotype AA (441 +/- 69 ms and 116 +/- 65 ms, p = 0.005 and p = 0.025, respectively). In males, the QTcmax and the Tpeak-Tend intervals did not differ between the genotypes. After adjustment for echocardiographic and various laboratory variables, the HERG K897T polymorphism remained as an independent predictor of QTcmax (p = 0.009) and the Tpeak-Tend intervals (p = 0.026) in females. CONCLUSIONS; The common K897T polymorphism of the HERG channel is associated with the maximal duration and transmural dispersion of ventricular repolarization in middle-aged females.
Division of Cardiology, Department of Medicine, University of Oulu, Oulu, Finland.
Eeva
E
Pietilä
Heidi
H
Fodstad
Elmo
E
Niskasaari
Päivi J
PJ
Laitinen P
Heikki
H
Swan
Markku
M
Savolainen
Y Antero
YA
Kesäniemi
Kimmo
K
Kontula
Heikki V
HV
Huikuri
D000328:Adult; D015992:Body Mass Index; D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; D000072237:ERG1 Potassium Channel; D004562:Electrocardiography; D051638:Ether-A-Go-Go Potassium Channels; D005260:Female; D005387:Finland / Q000453:epidemiology; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006339:Heart Rate / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011110:Polymorphism, Genetic / Q000235:genetics*; D015221:Potassium Channels / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D011237:Predictive Value of Tests; D012016:Reference Values; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG; D016387:Women's Health
D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; C072312:ERG protein, human; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human; C092509:KCNH6 protein, human; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG