title: Genetic admixture and asthma-related phenotypes in Mexican American and Puerto Rican asthmatics.
abstract: Genetic association studies in admixed populations may be biased if individual ancestry varies within the population and the phenotype of interest is associated with ancestry. However, recently admixed populations also offer potential benefits in association studies since markers informative for ancestry may be in linkage disequilibrium across large distances. In particular, the enhanced LD in admixed populations may be used to identify alleles that underlie a genetically determined difference in a phenotype between two ancestral populations. Asthma is known to have different prevalence and severity among ancestrally distinct populations. We investigated several asthma-related phenotypes in two ancestrally admixed populations: Mexican Americans and Puerto Ricans. We used ancestry informative markers to estimate the individual ancestry of 181 Mexican American asthmatics and 181 Puerto Rican asthmatics and tested whether individual ancestry is associated with any of these phenotypes independently of known environmental factors. We found an association between higher European ancestry and more severe asthma as measured by both forced expiratory volume at 1 second (r=-0.21, p=0.005) and by a clinical assessment of severity among Mexican Americans (OR: 1.55; 95% CI 1.25 to 1.93). We found no significant associations between ancestry and severity or drug responsiveness among Puerto Ricans. These results suggest that asthma severity may be influenced by genetic factors differentiating Europeans and Native Americans in Mexican Americans, although differing results for Puerto Ricans require further investigation.
authors.affiliation: Department of Medicine, University of California, San Francisco, California 94143-1732, USA.
authors.forename: Keyan
authors.initials: K
authors.lastname: Salari
authors.forename: Shweta
authors.initials: S
authors.lastname: Choudhry
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
authors.forename: Mariam
authors.initials: M
authors.lastname: Naqvi
authors.forename: Denise
authors.initials: D
authors.lastname: Lind
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Avila
authors.forename: Natasha E
authors.initials: NE
authors.lastname: Coyle
authors.forename: Ngim
authors.initials: N
authors.lastname: Ung
authors.forename: Sylvette
authors.initials: S
authors.lastname: Nazario
authors.forename: Jesus
authors.initials: J
authors.lastname: Casal
authors.forename: Alfonso
authors.initials: A
authors.lastname: Torres-Palacios
authors.forename: Suzanne
authors.initials: S
authors.lastname: Clark
authors.forename: Angie
authors.initials: A
authors.lastname: Phong
authors.forename: Ivan
authors.initials: I
authors.lastname: Gomez
authors.forename: Henry
authors.initials: H
authors.lastname: Matallana
authors.forename: Eliseo J
authors.initials: EJ
authors.lastname: Pérez-Stable
authors.forename: Mark D
authors.initials: MD
authors.lastname: Shriver
authors.forename: Pui-Yan
authors.initials: PY
authors.lastname: Kwok
authors.forename: Dean
authors.initials: D
authors.lastname: Sheppard
authors.forename: William
authors.initials: W
authors.lastname: Rodriguez-Cintron
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Risch
authors.forename: Esteban González
authors.initials: EG
authors.lastname: Burchard
authors.forename: Elad
authors.initials: E
authors.lastname: Ziv
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000208:ethnology* / Q000235:genetics*; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002648:Child; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects / Q000235:genetics; D005819:Genetic Markers; D005838:Genotype; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000235:genetics; D015810:Linkage Disequilibrium / Q000235:genetics*; D008297:Male; D017058:Mexican Americans / Q000235:genetics*; D010641:Phenotype; D011647:Puerto Rico / Q000208:ethnology; D012720:Severity of Illness Index
chemical_list: D001993:Bronchodilator Agents; D005819:Genetic Markers; D007073:Immunoglobulin E