title: Coding variant Met72Thr in the PEDF gene and risk of neovascular age-related macular degeneration and polypoidal choroidal vasculopathy.
abstract: OBJECTIVE
  Using a candidate-gene approach, a recent case-control study identified a previously unknown association between neovascular age-related macular degeneration (AMD) and the coding Met72Thr variant in the pigment epithelium-derived factor (PEDF) gene in a Taiwan Chinese population. However, a subsequent replication study failed to see this association in a white European population. We noted an important difference in the sample ascertainment scheme between these two studies. The original study did not consider findings of indocyanine green (ICG) angiography for disease classification, which is the only way to obtain a clear image of polypoidal choroidal vasculopathy (PCV) lesions. This suggests that their cohort might include a considerable amount of PCV, given its high prevalence in the Chinese population. In contrast, the replication study intentionally excluded PCV from the case cohort on the basis of ICG angiograms. Therefore, the inconsistent finding might be caused by potential sample heterogeneity between these two studies. In this respect, this association needed to be examined in a case series of clearly defined individuals with neovascular AMD and PCV. The aim of this study was to validate the previously reported association of the PEDF Met72Thr variant in a well characterized Japanese population with neovascular AMD and PCV.
  
  
  METHODS
  We genotyped the Met72Thr variant (rs1136287) in 116 patients with neovascular AMD, 140 patients with PCV, and 189 control participants in a Japanese population. Genotyping was performed using TaqMan technology. We tested for an association of this variant with neovascular AMD and PCV separately. We also evaluated population stratification in our study cohort.
  
  
  RESULTS
  We found no statistically significant evidence for association between rs1136287 and either neovascular AMD or PCV under any genetic models (trend, genotypic, dominant, and recessive genetic models; p>0.05). Population structure analyses excluded stratification artifact in our study population.
  
  
  CONCLUSIONS
  We report a lack of association between the PEDF Met72Thr variant and either neovascular AMD or PCV in a Japanese population. We conclude that the Met72Thr variant does not play a significant role in the risk of developing neovascular AMD or PCV.
authors.affiliation: Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Bessho
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kondo
authors.forename: Shigeru
authors.initials: S
authors.lastname: Honda
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kuno
authors.forename: Akira
authors.initials: A
authors.lastname: Negi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China; D002829:Choroid / Q000098:blood supply*; D015862:Choroid Diseases / Q000235:genetics*; D003627:Data Interpretation, Statistical; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D007564:Japan; D015810:Linkage Disequilibrium; D008268:Macular Degeneration / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D009154:Mutation; D009414:Nerve Growth Factors / Q000235:genetics*; D011123:Polyploidy; D015203:Reproducibility of Results; D015843:Serpins / Q000235:genetics*; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor