title: Association of apolipoprotein E alleles with susceptibility to age-related macular degeneration in a large cohort from a single center.
abstract: OBJECTIVE
  To examine the effect of apolipoprotein E (APOE) alleles on age-related macular degeneration (AMD) risk and on age at diagnosis of AMD in a large patient cohort recruited from a single center.
  
  
  METHODS
  The frequency of APOE alleles was analyzed in 632 unrelated AMD patients and 206 unrelated controls, all of whom were of white ancestry. The presence or absence of disease symptoms in all patients and controls was based on clinical examination and/or ophthalmic records. The association with APOE was explored in the context of AMD subtypes, family history status, possible interaction with smoking, and distribution of age at diagnosis of AMD.
  
  
  RESULTS
  The frequency of the epsilon4 allele was significantly reduced in patients compared with controls (0.10 vs. 0.14, P < or = 0.02). Gender- and age-adjusted odds ratios indicated that epsilon4-carriers have significantly lower risk of developing AMD compared to epsilon3epsilon3 subjects (OR = 0.55, 95% CI: 0.37-0.82, P = 0.004). In the cohort, AMD patients with a positive family history exhibited a significant 3.5 years earlier age at diagnosis (P = 0.001); however, APOE alleles did not appear to modulate the age at diagnosis of AMD.
  
  
  CONCLUSIONS
  The association between the APOE-epsilon4 allele and a reduced risk of AMD was established in a large cohort with sufficient statistical power. How distinct APOE alleles affect AMD susceptibility warrants further investigation.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48105, USA.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Zareparsi
authors.forename: Adam C
authors.initials: AC
authors.lastname: Reddick
authors.forename: Kari E H
authors.initials: KE
authors.lastname: Branham
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Moore
authors.forename: Laurie
authors.initials: L
authors.lastname: Jessup
authors.forename: Susan
authors.initials: S
authors.lastname: Thoms
authors.forename: Michael
authors.initials: M
authors.lastname: Smith-Wheelock
authors.forename: Beverly M
authors.initials: BM
authors.lastname: Yashar
authors.forename: Anand
authors.initials: A
authors.lastname: Swaroop
mesh_terms: D000368:Aged; D000483:Alleles; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D015331:Cohort Studies; D004247:DNA / Q000032:analysis; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D008297:Male; D012307:Risk Factors
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D004247:DNA