title: Dinucleotide repeat polymorphisms in EDN1 and NOS3 are not associated with severe diabetic retinopathy in type 1 or type 2 diabetes.
abstract: OBJECTIVE
  Endothelin-1, and constitutive endothelial nitric oxide synthase, have been implicated in the pathogenesis of diabetic retinopathy. We therefore screened polymorphisms within the genes encoding these two vasoactive agents in a sample of individuals with 15 years of diabetes and no retinopathy (ETDRS level 10 or better) and those with severe retinopathy (ETDRS level 50 or worse).
  
  
  METHODS
  PCR primers for highly polymorphic sites within the EDN1 and NOS3 genes were used to genotype individuals with type 1 or type 2 diabetes with severe or no retinopathy. Allele frequencies were compared between groups using chi-squared analysis and adjusting for multiple comparisons.
  
  
  RESULTS
  No significant differences were observed in allele frequencies for these two markers between the patients who had retinopathy and the patients who did not.
  
  
  CONCLUSIONS
  Polymorphic variability in the EDN1 and NOS3 genes does not appear to have a major impact on determining susceptibility or resistance to diabetic retinopathy.
authors.affiliation: Division of Ophthalmology and Vision Sciences Queen's University, Belfast, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Warpeha
authors.forename: F
authors.initials: F
authors.lastname: Ah-Fat
authors.forename: S
authors.initials: S
authors.lastname: Harding
authors.forename: C C
authors.initials: CC
authors.lastname: Patterson
authors.forename: W
authors.initials: W
authors.lastname: Xu
authors.forename: P M
authors.initials: PM
authors.lastname: Hart
authors.forename: U
authors.initials: U
authors.lastname: Chakravarthy
authors.forename: A E
authors.initials: AE
authors.lastname: Hughes
mesh_terms: D000328:Adult; D000483:Alleles; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D003930:Diabetic Retinopathy / Q000235:genetics*; D018900:Dinucleotide Repeats; D019332:Endothelin-1 / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052250:Nitric Oxide Synthase Type III; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
chemical_list: D019332:Endothelin-1; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III