title: A prospective study of 2 major age-related macular degeneration susceptibility alleles and interactions with modifiable risk factors.
abstract: OBJECTIVE
  To delineate the magnitude of susceptibility to age-related macular degeneration (AMD) due to common variants in the gene for complement factor H (CFH) and the predicted gene LOC387715 and to determine whether these variants interact with modifiable risk factors.
  
  
  METHODS
  We compared cases who developed AMD (n = 457) with 1071 age- and sex-matched control subjects in a prospective nested case-control study within the Nurses' Health Study and the Health Professionals Follow-up Study. We determined the incidence rate ratios and 95% confidence intervals (CIs) for AMD for each genotype and examined the interactions with modifiable risk factors.
  
  
  RESULTS
  Participants with 1 or 2 copies of the Y402H variant of CFH were, respectively, 1.98 (95% CI, 1.64-2.40) and 3.92 (95% CI, 2.69-5.76) times more likely to develop AMD, whereas the incident rate ratios (95% CIs) for 1 and 2 copies of LOC387715 A69S were 2.38 (1.92-2.96) and 5.66 (3.69-8.76), respectively. The fraction of AMD cases attributable to these 2 variants was 63% (95% CI, 58%-68%). Subjects homozygous for both risk alleles had a 50-fold increased risk of AMD (95% CI, 10.8-237), and cigarette smoking and obesity multiplied the risks associated with these variants.
  
  
  CONCLUSIONS
  Age-related macular degeneration has emerged as a paradigmatic example of a common disease caused by the interplay of genetic predisposition and exposure to modifiable risk factors.
authors.affiliation: Division of Preventive Medicine, Brigham and Women's Hospital, Boston, Mass, USA. dschaumberg@rics.bwh.harvard.edu
authors.forename: Debra A
authors.initials: DA
authors.lastname: Schaumberg
authors.forename: Susan E
authors.initials: SE
authors.lastname: Hankinson
authors.forename: Qun
authors.initials: Q
authors.lastname: Guo
authors.forename: Eric
authors.initials: E
authors.lastname: Rimm
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
mesh_terms: D000368:Aged; D000483:Alleles; D016022:Case-Control Studies; D017242:Complement Factor H / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006282:Health Personnel; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: C493495:CFH protein, human; D017242:Complement Factor H