Research article

Association of surfactant protein A polymorphisms with otitis media in infants at risk for asthma

Melinda M Pettigrew , Janneane F Gent , Yong Zhu , Elizabeth W Triche , Kathleen D Belanger , Theodore R Holford , Michael B Bracken and Brian P Leaderer

Yale Center for Perinatal, Pediatric and Environmental Epidemiology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT, USA

author email corresponding author email

BMC Medical Genetics 2006, 7:68doi:10.1186/1471-2350-7-68

Published:	2 August 2006

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).

Conclusion

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.