Multi-Ethnic Genome-Wide Association Study of Decomposed Cardioelectric Phenotypes Illustrates Strategies to Identify and Characterize Evidence of Shared Genetic Effects for Complex Traits

Circ Genom Precis Med. 2020 Aug;13(4):e002680. doi: 10.1161/CIRCGEN.119.002680. Epub 2020 Jun 30.

Abstract

Background: We examined how expanding electrocardiographic trait genome-wide association studies to include ancestrally diverse populations, prioritize more precise phenotypic measures, and evaluate evidence for shared genetic effects enabled the detection and characterization of loci.

Methods: We decomposed 10 seconds, 12-lead electrocardiograms from 34 668 multi-ethnic participants (15% Black; 30% Hispanic/Latino) into 6 contiguous, physiologically distinct (P wave, PR segment, QRS interval, ST segment, T wave, and TP segment) and 2 composite, conventional (PR interval and QT interval) interval scale traits and conducted multivariable-adjusted, trait-specific univariate genome-wide association studies using 1000-G imputed single-nucleotide polymorphisms. Evidence of shared genetic effects was evaluated by aggregating meta-analyzed univariate results across the 6 continuous electrocardiographic traits using the combined phenotype adaptive sum of powered scores test.

Results: We identified 6 novels (CD36, PITX2, EMB, ZNF592, YPEL2, and BC043580) and 87 known loci (adaptive sum of powered score test P<5×10-9). Lead single-nucleotide polymorphism rs3211938 at CD36 was common in Blacks (minor allele frequency=10%), near monomorphic in European Americans, and had effects on the QT interval and TP segment that ranked among the largest reported to date for common variants. The other 5 novel loci were observed when evaluating the contiguous but not the composite electrocardiographic traits. Combined phenotype testing did not identify novel electrocardiographic loci unapparent using traditional univariate approaches, although this approach did assist with the characterization of known loci.

Conclusions: Despite including one-third as many participants as published electrocardiographic trait genome-wide association studies, our study identified 6 novel loci, emphasizing the importance of ancestral diversity and phenotype resolution in this era of ever-growing genome-wide association studies.

Keywords: cardiovascular diseases; electrophysiology; epidemiology; genome-wide association study; population.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • African Americans / genetics
  • CD36 Antigens / genetics
  • Cardiovascular Diseases / ethnology
  • Cardiovascular Diseases / genetics*
  • Cardiovascular Diseases / physiopathology
  • Electrocardiography*
  • Gene Frequency
  • Genetic Loci
  • Genome-Wide Association Study*
  • Genotype
  • Hispanic or Latino / genetics
  • Homeodomain Proteins / genetics
  • Humans
  • Membrane Glycoproteins / genetics
  • Molecular Chaperones / genetics
  • Phenotype
  • Polymorphism, Single Nucleotide
  • Transcription Factors / genetics
  • Whites / genetics

Substances

  • CD36 Antigens
  • EMB protein, human
  • Homeodomain Proteins
  • Membrane Glycoproteins
  • Molecular Chaperones
  • Transcription Factors
  • homeobox protein PITX2

Grant support