Original Investigation
52 Genetic Loci Influencing Myocardial Mass

https://doi.org/10.1016/j.jacc.2016.07.729Get rights and content
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Abstract

Background

Myocardial mass is a key determinant of cardiac muscle function and hypertrophy. Myocardial depolarization leading to cardiac muscle contraction is reflected by the amplitude and duration of the QRS complex on the electrocardiogram (ECG). Abnormal QRS amplitude or duration reflect changes in myocardial mass and conduction, and are associated with increased risk of heart failure and death.

Objectives

This meta-analysis sought to gain insights into the genetic determinants of myocardial mass.

Methods

We carried out a genome-wide association meta-analysis of 4 QRS traits in up to 73,518 individuals of European ancestry, followed by extensive biological and functional assessment.

Results

We identified 52 genomic loci, of which 32 are novel, that are reliably associated with 1 or more QRS phenotypes at p < 1 × 10−8. These loci are enriched in regions of open chromatin, histone modifications, and transcription factor binding, suggesting that they represent regions of the genome that are actively transcribed in the human heart. Pathway analyses provided evidence that these loci play a role in cardiac hypertrophy. We further highlighted 67 candidate genes at the identified loci that are preferentially expressed in cardiac tissue and associated with cardiac abnormalities in Drosophila melanogaster and Mus musculus. We validated the regulatory function of a novel variant in the SCN5A/SCN10A locus in vitro and in vivo.

Conclusions

Taken together, our findings provide new insights into genes and biological pathways controlling myocardial mass and may help identify novel therapeutic targets.

Key Words

electrocardiogram
genetic association study
heart failure
left ventricular hypertrophy
QRS

Abbreviations and Acronyms

DHS
deoxyribonuclease hypersensitivity sites
ECG
electrocardiogram
eQTL
expression quantitative trait locus
GWAS
genome-wide association study
LD
linkage disequilibrium
RNAi
ribonucleic acid interference
SNP
single nucleotide polymorphism
TF
transcription factor

Cited by (0)

Dr. Abecasis has served on the scientific advisory board for Regeneron Genetics Center. Dr. Haugen’s current employer (Altius Institute) receives research funding from GlaxoSmithKline. Dr. Pennacchio is a salaried employee and owns stock in Metabiota. Dr. Stamatoyannopoulos is the director of a nonprofit research institute. Dr. Psaty has served on the data and safety monitoring board for a clinical trial funded by Zoll LifeCor; and has served on the steering committee of the Yale Open Data Access project funded by Johnson & Johnson. Dr. de Bakker is currently an employee of and owns equity in Vertex Pharmaceuticals. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. van der Harst, van Setten, Verweij, Vogler, Franke, Maurano, Wang, Mateo Leach, Chambers, Jamshidi, Visel, Christoffels, Isaacs, Samani, and de Bakker contributed equally to this work.

Listen to this manuscript's audio summary by JACC Editor-in-Chief Dr. Valentin Fuster.