title: Case-control admixture mapping in Latino populations enriches for known asthma-associated genes.
abstract: BACKGROUND
  Polymorphisms in more than 100 genes have been associated with asthma susceptibility, yet much of the heritability remains to be explained. Asthma disproportionately affects different racial and ethnic groups in the United States, suggesting that admixture mapping is a useful strategy to identify novel asthma-associated loci.
  
  
  OBJECTIVE
  We sought to identify novel asthma-associated loci in Latino populations using case-control admixture mapping.
  
  
  METHODS
  We performed genome-wide admixture mapping by comparing levels of local Native American, European, and African ancestry between children with asthma and nonasthmatic control subjects in Puerto Rican and Mexican populations. Within candidate peaks, we performed allelic tests of association, controlling for differences in local ancestry.
  
  
  RESULTS
  Between the 2 populations, we identified a total of 62 admixture mapping peaks at a P value of less than 10(-3) that were significantly enriched for previously identified asthma-associated genes (P= .0051). One of the peaks was statistically significant based on 100 permutations in the Mexican sample (6q15); however, it was not significant in Puerto Rican subjects. Another peak was identified at nominal significance in both populations (8q12); however, the association was observed with different ancestries.
  
  
  CONCLUSIONS
  Case-control admixture mapping is a promising strategy for identifying novel asthma-associated loci in Latino populations and implicates genetic variation at 6q15 and 8q12 regions with asthma susceptibility. This approach might be useful for identifying regions that contribute to both shared and population-specific differences in asthma susceptibility.
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA 94158, USA. dara.torgerson@ucsf.edu
authors.forename: Dara G
authors.initials: DG
authors.lastname: Torgerson
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Gignoux
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Galanter
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Drake
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Roth
authors.forename: Celeste
authors.initials: C
authors.lastname: Eng
authors.forename: Scott
authors.initials: S
authors.lastname: Huntsman
authors.forename: Raul
authors.initials: R
authors.lastname: Torres
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Avila
authors.forename: Rocio
authors.initials: R
authors.lastname: Chapela
authors.forename: Jean G
authors.initials: JG
authors.lastname: Ford
authors.forename: José R
authors.initials: JR
authors.lastname: Rodríguez-Santana
authors.forename: William
authors.initials: W
authors.lastname: Rodríguez-Cintrón
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Hernandez
authors.forename: Esteban G
authors.initials: EG
authors.lastname: Burchard
mesh_terms: D000293:Adolescent; D000328:Adult; D044467:American Indian or Alaska Native; D001249:Asthma / Q000208:ethnology* / Q000235:genetics*; D044383:Black People / Q000235:genetics; D016022:Case-Control Studies; D002648:Child; D002874:Chromosome Mapping; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006630:Hispanic or Latino / Q000208:ethnology* / Q000235:genetics*; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012307:Risk Factors; D014481:United States / Q000208:ethnology; D044465:White People / Q000235:genetics; D055815:Young Adult; D001741:Black or African American