title: Comparing age-related macular degeneration phenotype in probands from singleton and multiplex families.
abstract: OBJECTIVE
  To compare age-related macular degeneration (AMD) phenotype between probands in singleton and multiplex families to determine whether data from these two groups may be combined for consolidated genetic analyses.
  
  
  METHODS
  Retrospective case-control study.
  
  
  METHODS
  Individuals 55 years of age or older with AMD were identified. Complete histories and examinations were recorded, 35-mm fundus photographs obtained, and macular findings graded. Detailed information was recorded, including the presence of extramacular and peripheral drusen, peripheral reticular pigmentary change, posterior vitreous detachment, and iris color. Comparisons were performed between probands from singleton and multiplex families.
  
  
  RESULTS
  There was no statistically significant difference in grade between the 411 singleton and 125 multiplex probands (P = .52), and the distribution of grades was similar between the two groups. No statistically significant difference was found between proband groups with respect to the presence or extent of small (P = .48), intermediate (P = .72), and large drusen (P = .74) and retinal pigment epithelium hyper- (P = .76) and hypopigmentation (P = .55); in the presence or grade of peripheral reticular pigment change; the presence of geographic atrophy in exudative disease, extramacular drusen, or posterior vitreous detachment; lens status; iris color; visual acuity; intraocular pressure; optic nerve cupping; and body mass index. A statistically significant difference between the two groups was noted in the presence of peripheral drusen (P = .0001).
  
  
  CONCLUSIONS
  Singleton and multiplex AMD probands share a similar phenotype. This suggests that multiplex and singleton data can be combined for consolidated genetic analyses.
authors.affiliation: Duke University Eye Center, Box 3802, Durham, NC 27710, USA. poste002@mc.duke.edu
authors.forename: Eric A
authors.initials: EA
authors.lastname: Postel
authors.forename: Anita
authors.initials: A
authors.lastname: Agarwal
authors.forename: Silke
authors.initials: S
authors.lastname: Schmidt
authors.forename: Yu-Ti R
authors.initials: YT
authors.lastname: Fan
authors.forename: William K
authors.initials: WK
authors.lastname: Scott
authors.forename: John R
authors.initials: JR
authors.lastname: Gilbert
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Haines
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Pericak-Vance
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000145:classification / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009679:Nuclear Family; D010641:Phenotype; D012189:Retrospective Studies