title: Association of surfactant protein A polymorphisms with otitis media in infants at risk for asthma.
abstract: BACKGROUND
  Otitis media is one of the most common infections of early childhood. Surfactant protein A functions as part of the innate immune response, which plays an important role in preventing infections early in life. This prospective study utilized a candidate gene approach to evaluate the association between polymorphisms in loci encoding SP-A and risk of otitis media during the first year of life among a cohort of infants at risk for developing asthma.
  
  
  METHODS
  Between September 1996 and December 1998, women were invited to participate if they had at least one other child with physician-diagnosed asthma. Each mother was given a standardized questionnaire within 4 months of her infant's birth. Infant respiratory symptoms were collected during quarterly telephone interviews at 6, 9 and 12 months of age. Genotyping was done on 355 infants for whom whole blood and complete otitis media data were available.
  
  
  RESULTS
  Polymorphisms at codons 19, 62, and 133 in SP-A1, and 223 in SP-A2 were associated with race/ethnicity. In logistic regression models incorporating estimates of uncertainty in haplotype assignment, the 6A4/1A5haplotype was protective for otitis media among white infants in our study population (OR 0.23; 95% CI 0.07,0.73).
  
  
  CONCLUSIONS
  These results indicate that polymorphisms within SP-A loci may be associated with otitis media in white infants. Larger confirmatory studies in all ethnic groups are warranted.
authors.affiliation: Yale Center for Perinatal, Pediatric and Environmental Epidemiology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT, USA. melinda.pettigrew@yale.edu
authors.forename: Melinda M
authors.initials: MM
authors.lastname: Pettigrew
authors.forename: Janneane F
authors.initials: JF
authors.lastname: Gent
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhu
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Triche
authors.forename: Kathleen D
authors.initials: KD
authors.lastname: Belanger
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Holford
authors.forename: Michael B
authors.initials: MB
authors.lastname: Bracken
authors.forename: Brian P
authors.initials: BP
authors.lastname: Leaderer
mesh_terms: D000483:Alleles; D001249:Asthma / Q000150:complications*; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007223:Infant; D008297:Male; D010033:Otitis Media / Q000150:complications / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics*; D012306:Risk; D044465:White People / Q000235:genetics
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A