title: Endothelial nitric oxide synthase genotypes in the etiology of retinopathy of prematurity in premature infants.
abstract: OBJECTIVE
  Retinopathy of Prematurity (ROP) is a vasoproliferative disorder affecting preterm infants leading to visual impairment. ROP is more common in Caucasians than African Americans. Very low birth weight infants have immature retinas and are susceptible to ROP. Because of differences in individual responses to the treatment, various genetic factors have been looked into to understand the etiology of ROP. Endothelial nitric oxide (eNO) serves as a vasodilator, relaxes smooth muscle, prevents platelet aggregation, and facilitates improved blood flow and vascular tonicity. Mutant eNO synthase (eNOS) genotypes result in reduced nitric oxide levels by decreasing enzyme activity. Since eNO affects vasculature and ROP is a vascular disease, the present investigation was aimed at studying the association of genotypes with ROP.
  
  
  METHODS
  Two eNOS gene single nucleotide polymorphisms (SNPs) (T-786C, and G894T) were studied by microplate-Restriction Fragment Length Polymorphism Polymerase Chain Reaction (RFLP PCR) method. Genotypes were studied in 146 premature infants.
  
  
  RESULTS
  The present data showed significant differences in the baseline gene frequencies between Caucasians and African Americans. ROP patients displayed 3-fold higher frequencies of mutant -786C and 894T alleles in both ethnicities compared to respective controls.
  
  
  CONCLUSIONS
  The present data suggest ethnic stratification of genotypes. Mutant -786C and 894T alleles are significant risk factors in the development of ROP, and suggest a strong association between eNOS polymorphisms and the disease. It is interesting to know if a larger dataset of ROP patients can confirm our initial findings.
authors.affiliation: Department of Pediatrics, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71103, USA. kyanam@lsuhsc.edu
authors.forename: Krishna
authors.initials: K
authors.lastname: Yanamandra
authors.forename: Dawn
authors.initials: D
authors.lastname: Napper
authors.forename: Arun
authors.initials: A
authors.lastname: Pramanik
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Bocchini
authors.forename: Ramasubbareddy
authors.initials: R
authors.lastname: Dhanireddy
mesh_terms: D001741:Black or African American; D005787:Gene Frequency; D005838:Genotype; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D012178:Retinopathy of Prematurity / Q000201:enzymology / Q000235:genetics*; D044465:White People
chemical_list: D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III