title: Association of Insulin-Like Growth Factor-1 Gene Polymorphisms with Different Types of Myopia in Egyptian Patients.
abstract: OBJECTIVE
  To investigate the effect of the insulin-like growth factor-1 (IGF-1) gene's rs6214 and rs5742632 polymorphisms on IGF-1 expression levels and their association with different types of myopia in Egyptian patients.
  
  
  METHODS
  A case-control format was used that included 272 patients with myopia and 136 controls. The IGF-1 gene rs6214 and rs5742632 polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses. IGF-1 levels were measured by an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  In patients with high-grade myopia, the frequencies of the IGF-1 rs6214 GA and AA genotypes, and the A allele were significantly increased compared to the control group: 41.9% vs. 33.8%, 17.7% vs. 8.9%, and 38.9% vs. 25.7%, respectively. Subjects with the GA and AA genotypes and carriers of A allele were significantly more likely to have high-grade myopia: odds ratios (OR) = 1.75, 95% confidence interval (CI) = 1.03-2.9, and p = 0.03; OR = 2.8, 95% CI = 1.3-6.0, and p = 0.003; and OR = 1.8, 95% CI = 1.25-2.61, and p = 0.001, respectively. A nonsignificant association of the IGF-1 gene rs5742632 polymorphism with the two myopia groups was also observed. The IGF-1 levels were significantly increased in patients with high-grade myopia and simple myopia compared to the control group (p < 0.05). In addition, our results showed a nonsignificant association of the IGF-1 (rs6214-rs5742632) haplotype with either simple myopia or high-grade myopia.
  
  
  CONCLUSIONS
  We found a significant association of the IGF-1 gene rs6214 polymorphism in Egyptian patients with simple myopia and high-grade myopia. IGF-1 levels were significantly increased in relation to the IGF-1 rs6214 genotypes, while a nonsignificant association was found between IGF-1 level and the IGF-1 (rs5742632) genotypes.
authors.affiliation: 1 Medical Biochemistry Department, Faculty of Medicine, Zagazig University , Zagazig, Egypt .
authors.forename: Haidy E
authors.initials: HE
authors.lastname: Zidan
authors.affiliation: 1 Medical Biochemistry Department, Faculty of Medicine, Zagazig University , Zagazig, Egypt .
authors.forename: Noha A
authors.initials: NA
authors.lastname: Rezk
authors.affiliation: 2 Department of Ophthalmology, Faculty of Medicine, Zagazig University , Zagazig, Egypt .
authors.forename: Sameh M
authors.initials: SM
authors.lastname: Fouda
authors.affiliation: 2 Department of Ophthalmology, Faculty of Medicine, Zagazig University , Zagazig, Egypt .
authors.forename: Hala K
authors.initials: HK
authors.lastname: Mattout
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D004534:Egypt; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide
chemical_list: D007334:Insulin-Like Growth Factor I