2013 Articles

Genome Wide Analysis of Drug-Induced Torsades de Pointes: Lack of Common Variants with Large Effect Sizes

Behr, Elijah R.; Ritchie, Marylyn D.; Tanaka, Toshihiro; Kääb, Stefan; Crawford, Dana C.; Nicoletti, Paola; Floratos, Aristidis; Kannankeril, Prince J.; Sinner, Moritz F.; M. Wilde, Arthur A.; Bezzina, Connie R.; Schulze-Bahr, Eric; Zumhagen, Sven; Guicheney, Pascale; Bishopric, Nanette H.; Marshall, Vanessa; Shakir, Saad; Dalageorgou, Chrysoula; Jamshidi, Yalda; Bevan, Steve; Bastiaenen, Rachel; Myerburg, Robert J.; Schott, Jean-Jacques; Camm, A. John; Steinbeck, Gerhard; Norris, Kris; Altman, Russ B.; Tatonetti, Nicholas P.; Jeffery, Steve; Kubo, Michiaki; Nakamura, Yusuke; Shen, Yufeng; George Jr, Alfred L.; Roden, Dan M.

Marked prolongation of the QT interval on the electrocardiogram associated with the polymorphic ventricular tachycardia Torsades de Pointes is a serious adverse event during treatment with antiarrhythmic drugs and other culprit medications, and is a common cause for drug relabeling and withdrawal. Although clinical risk factors have been identified, the syndrome remains unpredictable in an individual patient. Here we used genome-wide association analysis to search for common predisposing genetic variants. Cases of drug-induced Torsades de Pointes (diTdP), treatment tolerant controls, and general population controls were ascertained across multiple sites using common definitions, and genotyped on the Illumina 610k or 1M-Duo BeadChips. Principal Components Analysis was used to select 216 Northwestern European diTdP cases and 771 ancestry-matched controls, including treatment-tolerant and general population subjects. With these sample sizes, there is 80% power to detect a variant at genome-wide significance with minor allele frequency of 10% and conferring an odds ratio of ≥2.7. Tests of association were carried out for each single nucleotide polymorphism (SNP) by logistic regression adjusting for gender and population structure. No SNP reached genome wide-significance; the variant with the lowest P value was rs2276314, a non-synonymous coding variant in C18orf21 (p  =  3×10−7, odds ratio = 2, 95% confidence intervals: 1.5–2.6). The haplotype formed by rs2276314 and a second SNP, rs767531, was significantly more frequent in controls than cases (p  =  3×10−9). Expanding the number of controls and a gene-based analysis did not yield significant associations. This study argues that common genomic variants do not contribute importantly to risk for drug-induced Torsades de Pointes across multiple drugs.