title: A NOS1 gene polymorphism associated with asthma and specific immunoglobulin E response to mite allergens in a Colombian population.
abstract: BACKGROUND
  Nitric oxide (NO) is involved in asthma pathogenesis and is synthesized by three isoforms of NO synthase, one of them encoded by NOS1 gene. The CA-repeat and the C5266T SNP in NOS1 exon 29 have been associated with asthma and IgE levels. We thought to test the association of asthma and asthma-related phenotypes with the exon 29 CA-repeat and the C5266T SNP in a Colombian population sample.
  
  
  METHODS
  The CA-repeat and the C5266T SNP were genotyped in 167 asthmatics and 166 controls using PCR-based fragment length polymorphism and TaqMan assay. We also determined total and mite-specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus.
  
  
  RESULTS
  Three new CA-repeat alleles, 14, 23 and 24 repeats were detected. Allele comprising 16 repeats was associated with asthma (OR: 1.90 (CI 1.22-2.97, p(c) = 0.028) and low total (p(c) = 0.02) and specific IgE to B. tropicalis (p(c) < 0.0001) and D. pteronyssinus (p(c) < 0.0001). We found no association of the C5266T SNP and asthma or IgE levels.
  
  
  CONCLUSIONS
  NOS1 exon 29 CA-repeat may be a risk factor for asthma susceptibility and mite specific IgE response in a Colombian population.
authors.affiliation: Institute for Immunological Research, University of Cartagena, Cartagena, Colombia.
authors.forename: B
authors.initials: B
authors.lastname: Martínez
authors.forename: K
authors.initials: K
authors.lastname: Barrios
authors.forename: C
authors.initials: C
authors.lastname: Vergara
authors.forename: D
authors.initials: D
authors.lastname: Mercado
authors.forename: S
authors.initials: S
authors.lastname: Jiménez
authors.forename: L
authors.initials: L
authors.lastname: Gusmão
authors.forename: L
authors.initials: L
authors.lastname: Caraballo
mesh_terms: D000053:Acari; D000328:Adult; D000483:Alleles; D000485:Allergens / Q000276:immunology*; D000818:Animals; D001249:Asthma / Q000235:genetics* / Q000276:immunology; D003105:Colombia; D040002:Dermatophagoides pteronyssinus; D018900:Dinucleotide Repeats / Q000235:genetics; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D052248:Nitric Oxide Synthase Type I / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D000485:Allergens; D007073:Immunoglobulin E; C496320:NOS1 protein, human; D052248:Nitric Oxide Synthase Type I