title: Association between apolipoprotein E polymorphisms and age-related macular degeneration: A HuGE review and meta-analysis.
abstract: A possible association between apolipoprotein E polymorphisms and age-related macular degeneration has been investigated numerous times, with conflicting results. A previous analysis pooling results from four studies (Schmidt et al., Ophthalmic Genet 2002;23:209-23) suggested an association, but those investigators did not document allele frequencies, the magnitude of the association, or the possible genetic mode of action. Thus, the authors searched MEDLINE from 1966 to December 2005 for any English-language studies reporting genetic associations. Data and study quality were assessed in duplicate. Pooling was performed while checking for heterogeneity and publication bias. Frequencies of the E2 and E4 alleles in Caucasians were approximately 8% and 15%, respectively. Allele- and genotype-based tests of association indicated a risk effect of up to 20% for E2 and a protective effect of up to 40% for E4. E2 appeared to act in a recessive mode and E4 in a dominant mode. There appears to be a differential effect of the E2 and E4 alleles on the risk of age-related macular degeneration, although the possibility of survivor bias needs to be ruled out more definitively.
authors.affiliation: Clinical Epidemiology Unit, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Ammarin
authors.initials: A
authors.lastname: Thakkinstian
authors.forename: Steve
authors.initials: S
authors.lastname: Bowe
authors.forename: Mark
authors.initials: M
authors.lastname: McEvoy
authors.forename: Wayne
authors.initials: W
authors.lastname: Smith
authors.forename: John
authors.initials: J
authors.lastname: Attia
mesh_terms: D000483:Alleles; D001057:Apolipoproteins E / Q000235:genetics*; D044466:Asian People / Q000235:genetics; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000208:ethnology / Q000235:genetics*; D011110:Polymorphism, Genetic; D044465:White People / Q000235:genetics
chemical_list: D001057:Apolipoproteins E