title: Age-related macular degeneration: the importance of family history as a risk factor.
abstract: BACKGROUND
  Family history is considered a risk factor for age-related macular degeneration (AMD). With the advent of effective therapy for the disease, the importance of family history merits further investigation. This study quantifies the risk associated with family history, first, by a case-control study of reported family history and, second, by examining the siblings of AMD cases.
  
  
  METHODS
  The authors recruited cases with advanced AMD, spouses and siblings. All subjects were carefully phenotyped. Clinical findings in the siblings were compared with spouses. Information about family history was collected. The ORs for reported family history of AMD were calculated. Analyses were adjusted for age, smoking and genotype.
  
  
  RESULTS
  495 AMD cases, 259 spouses and 171 siblings were recruited. The OR for AMD was 27.8 (CI 3.8 to 203.0; p=0.001) with a reported family history of an affected parent and 12.0 (CI 3.7 to 38.6; p<0.0001) with a history of an affected sibling. ORs adjusted for age and smoking were higher. Examination of siblings confirmed their increased risk with 23% affected by AMD and an OR of 10.8 (4.5 to 25.8; p<0.0001). Adjusting for age increased the OR to 16.1 (6.2 to 41.8).
  
  
  CONCLUSIONS
  The risk of AMD is greatly increased by having an affected first-degree relative. Those at risk need to be made aware of this and AMD patients should advise siblings and children to seek prompt ophthalmological advice if they develop visual symptoms of distortion or reduced vision.
authors.affiliation: Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK. hummashahid@hotmail.com
authors.forename: Humma
authors.initials: H
authors.lastname: Shahid
authors.forename: Jane C
authors.initials: JC
authors.lastname: Khan
authors.forename: Valentina
authors.initials: V
authors.lastname: Cipriani
authors.forename: Tiina
authors.initials: T
authors.lastname: Sepp
authors.forename: Baljinder K
authors.initials: BK
authors.lastname: Matharu
authors.forename: Catey
authors.initials: C
authors.lastname: Bunce
authors.forename: Simon P
authors.initials: SP
authors.lastname: Harding
authors.forename: David G
authors.initials: DG
authors.lastname: Clayton
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Moore
authors.forename: John R W
authors.initials: JR
authors.lastname: Yates
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003176:Complement C3 / Q000235:genetics; D011415:Complement Factor B / Q000235:genetics; D017242:Complement Factor H / Q000235:genetics; D005192:Family Health; D005260:Female; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D011506:Proteins / Q000235:genetics; D012307:Risk Factors; D012801:Sibling Relations; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000453:epidemiology* / Q000235:genetics
chemical_list: C514392:ARMS2 protein, human; C493495:CFH protein, human; D003176:Complement C3; D011506:Proteins; D017242:Complement Factor H; D011415:Complement Factor B