Mapping the 17q12-21.1 Locus for Variants Associated with Early-Onset Asthma in African Americans

Am J Respir Crit Care Med. 2021 Feb 15;203(4):424-436. doi: 10.1164/rccm.202006-2623OC.


Rationale: The 17q12-21.1 locus is one of the most highly replicated genetic associations with asthma. Individuals of African descent have lower linkage disequilibrium in this region, which could facilitate identifying causal variants.Objectives: To identify functional variants at 17q12-21.1 associated with early-onset asthma among African American individuals.Methods: We evaluated African American participants from SAPPHIRE (Study of Asthma Phenotypes and Pharmacogenomic Interactions by Race-Ethnicity) (n = 1,940), SAGE II (Study of African Americans, Asthma, Genes and Environment) (n = 885), and GCPD-A (Study of the Genetic Causes of Complex Pediatric Disorders-Asthma) (n = 2,805). Associations with asthma onset at ages under 5 years were meta-analyzed across cohorts. The lead signal was reevaluated considering haplotypes informed by genetic ancestry (i.e., African vs. European). Both an expression-quantitative trait locus analysis and a phenome-wide association study were performed on the lead variant.Measurements and Main Results: The meta-analyzed results from SAPPHIRE, SAGE II, and the GCPD-A identified rs11078928 as the top association for early-onset asthma. A haplotype analysis suggested that the asthma association partitioned most closely with the rs11078928 genotype. Genetic ancestry did not appear to influence the effect of this variant. In the expression-quantitative trait locus analysis, rs11078928 was related to alternative splicing of GSDMB (gasdermin-B) transcripts. The phenome-wide association study of rs11078928 suggested that this variant was predominantly associated with asthma and asthma-associated symptoms.Conclusions: A splice-acceptor polymorphism appears to be a causal variant for asthma at the 17q12-21.1 locus. This variant appears to have the same magnitude of effect in individuals of African and European descent.

Keywords: African Americans; GSDMB; ORMDL3; asthma; chromosome 17.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Asthma / genetics
  • Black or African American / genetics*
  • Child
  • Child, Preschool
  • Chromosome Mapping
  • Chromosomes, Human, Pair 17*
  • Female
  • Genetic Association Studies*
  • Genetic Predisposition to Disease / genetics*
  • Genetic Variation
  • Humans
  • Infant
  • Infant, Newborn
  • Linkage Disequilibrium
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide
  • Quantitative Trait Loci
  • United States
  • White People / genetics*
  • Young Adult