Genome-wide association study and admixture mapping reveal new loci associated with total IgE levels in Latinos

J Allergy Clin Immunol. 2015 Jun;135(6):1502-10. doi: 10.1016/j.jaci.2014.10.033. Epub 2014 Dec 6.

Abstract

Background: IgE is a key mediator of allergic inflammation, and its levels are frequently increased in patients with allergic disorders.

Objective: We sought to identify genetic variants associated with IgE levels in Latinos.

Methods: We performed a genome-wide association study and admixture mapping of total IgE levels in 3334 Latinos from the Genes-environments & Admixture in Latino Americans (GALA II) study. Replication was evaluated in 454 Latinos, 1564 European Americans, and 3187 African Americans from independent studies.

Results: We confirmed associations of 6 genes identified by means of previous genome-wide association studies and identified a novel genome-wide significant association of a polymorphism in the zinc finger protein 365 gene (ZNF365) with total IgE levels (rs200076616, P = 2.3 × 10(-8)). We next identified 4 admixture mapping peaks (6p21.32-p22.1, 13p22-31, 14q23.2, and 22q13.1) at which local African, European, and/or Native American ancestry was significantly associated with IgE levels. The most significant peak was 6p21.32-p22.1, where Native American ancestry was associated with lower IgE levels (P = 4.95 × 10(-8)). All but 22q13.1 were replicated in an independent sample of Latinos, and 2 of the peaks were replicated in African Americans (6p21.32-p22.1 and 14q23.2). Fine mapping of 6p21.32-p22.1 identified 6 genome-wide significant single nucleotide polymorphisms in Latinos, 2 of which replicated in European Americans. Another single nucleotide polymorphism was peak-wide significant within 14q23.2 in African Americans (rs1741099, P = 3.7 × 10(-6)) and replicated in non-African American samples (P = .011).

Conclusion: We confirmed genetic associations at 6 genes and identified novel associations within ZNF365, HLA-DQA1, and 14q23.2. Our results highlight the importance of studying diverse multiethnic populations to uncover novel loci associated with total IgE levels.

Keywords: Hispanics; IgE; Latinos; admixture mapping; allergy; asthma; genome-wide association study; minority populations; next-generation sequencing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Black or African American
  • Child
  • Chromosome Mapping
  • Chromosomes, Human, Pair 14 / chemistry
  • DNA-Binding Proteins / genetics
  • Female
  • Genetic Loci*
  • Genome, Human
  • Genome-Wide Association Study*
  • Genotype*
  • HLA-DQ alpha-Chains / genetics
  • Hispanic or Latino*
  • Humans
  • Immunoglobulin E / genetics*
  • Male
  • Polymorphism, Single Nucleotide*
  • Transcription Factors / genetics
  • White People

Substances

  • DNA-Binding Proteins
  • HLA-DQ alpha-Chains
  • HLA-DQA1 antigen
  • Transcription Factors
  • ZNF365 protein, human
  • Immunoglobulin E

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