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Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Relationship of common candidate gene variants to electrocardiographic T-wave peak to T-wave end interval and T-wave
Kimmo Porthan1, Annukka Marjamaa, Matti Viitasalo
1Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland. kimmo.porthan@fimnet.fi
Background:
Single-nucleotide polymorphisms (SNPs) in genes encoding cardiac ion channels and nitric oxide synthase-1 adaptor protein (NOS1AP) are associated with electrocardiographic (ECG) QT-interval duration, but the association of these SNPs with new, prognostically important ECG measures of ventricular repolarization is unknown.
Objective:
The purpose of this study was to examine the relationship of SNPs to ECG T-wave peak to T-wave end (TPE) interval and T-wave morphology parameters.
Methods:
We studied 5,890 adults attending the Health 2000 Study, a Finnish epidemiologic survey. TPE interval and four T-wave morphology parameters were measured from digital 12-lead ECGs and related to the seven SNPs showing a phenotypic effect on QT-interval duration in the Health 2000 Study population.
Results:
In multivariable analyses, the KCNH2 K897T minor allele was associated with a 1.2-ms TPE-interval shortening (P = .00005) and the KCNH2 intronic rs3807375 minor allele was associated with a 0.8-ms TPE-interval prolongation (P = .001), whereas the KCNE1 D85N variant had no TPE-interval effect (P = .20). NOS1AP minor alleles (rs2880058, rs4657139, rs10918594, rs10494366) were associated with a shorter TPE interval (effects from 0.5 to 0.8 ms, P from .032 to .002), which resulted from their stronger effects on QT(peak) than QT(end) interval. None of the SNPs showed a consistent association with T-wave morphology parameters.
Conclusion:
KCNH2 K897T and rs3807375 as well as the four studied NOS1AP variants have modest effects on ECG TPE interval but are not related to T-wave morphology measures. The previously observed prognostic value of T-wave morphology parameters likely is not based on these SNPs.
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