title: Relationship of the Glu298Asp polymorphism of the endothelial nitric oxide synthase gene and early-onset coronary artery disease.
abstract: BACKGROUND
  The Glu298Asp polymorphism of endothelial nitric oxide synthase (eNOS) gene has been associated with coronary artery disease (CAD) in some but not all studies. To determine the impact of the mutant Asp298 eNOS allele on the development of premature CAD, we examined the prevalence of this mutation in patients with early-onset CAD compared with those manifesting CAD later in life. If this mutation confers an increased risk of premature CAD, we hypothesized that the frequency of the homozygous mutation (Asp298Asp298) would be greater among the younger patient group.
  
  
  METHODS
  A total of 299 patients with a history of myocardial infarction (MI) or angina pectoris plus angiographically documented CAD were studied. Patients were divided into 2 groups: group 1 (149 patients) included patients with CAD before the age of 50 years and group 2 (150 patients) included patients with a first presentation of CAD at >65 years old. Prevalence of eNOS Glu298 and Asp298 alleles was assessed by molecular analysis and compared for the 2 groups.
  
  
  RESULTS
  There was no significant difference in the frequency of the mutant Asp298 allele between the 2 groups (G1: 42% vs G2: 42.7%, P =.79). The frequencies of the Glu298Glu298, Glu298Asp298, and Asp298Asp298 genotypes were similar in both groups (34.9%, 46.3%, and 18.8% for G1 and 29.3%, 56%, and 14.7% for G2, respectively, P =.29).
  
  
  CONCLUSIONS
  Our study does not support the conclusion that the eNOS Asp298 allele contributes to the development of premature CAD.
authors.affiliation: Department of Pathology, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada. plmban@qe2-hsc.ns.ca
authors.forename: B A
authors.initials: BA
authors.lastname: Nassar
authors.forename: L D
authors.initials: LD
authors.lastname: Bevin
authors.forename: D E
authors.initials: DE
authors.lastname: Johnstone
authors.forename: B J
authors.initials: BJ
authors.lastname: O'neill
authors.forename: I R
authors.initials: IR
authors.lastname: Bata
authors.forename: S A
authors.initials: SA
authors.lastname: Kirkland
authors.forename: L M
authors.initials: LM
authors.lastname: Title
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D003327:Coronary Disease / Q000201:enzymology / Q000235:genetics*; D004727:Endothelium / Q000201:enzymology; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D019001:Nitric Oxide Synthase