title: Toll-like receptor polymorphisms and age-related macular degeneration.
abstract: OBJECTIVE
  Evidence from genetic-association studies in conjunction with the demonstration of complement deposition in the retina and choroid implicates noncellular pathways of innate immunity in the pathogenesis of age-related macular degeneration (AMD). The purpose of this study was to determine whether common variation in the 10 human toll-like receptors (TLRs) alters the risk of AMD.
  
  
  METHODS
  Sixty-eight SNPs were iteratively genotyped across the TLR genes in a cohort of 577 subjects, with and without AMD. Two additional cohorts were used for replication studies. Standard genetic-association methods were used to analyze the results for association with disease and interaction with other loci.
  
  
  RESULTS
  Coding SNPs in TLR3 (rs3775291) and TLR7 (rs179008) showed association with AMD in one group (P = 0.01 and P = 0.02, respectively) before correction for multiple testing. For both SNPs, the association with AMD arose due to an excess of heterozygotes compared with homozygotes for the major allele. The two coding SNPs were not associated with AMD in another case-control cohort or an extended-family cohort. Although an intronic SNP in TLR4 was associated marginally with AMD (P = 0.03), it was not possible to replicate a previous association with the rare coding SNP D299G in this gene (P = 0.6).
  
  
  CONCLUSIONS
  Although borderline support for association between polymorphisms in TLR genes and AMD was reported for some cohorts, these initial observations of coding SNPs in TLR3, TLR4, and TLR7 were not replicated. TLR variants are unlikely to have a major impact on overall AMD risk, and the common variants studied were not associated with AMD.
authors.affiliation: Department of Ophthalmology, Mayor Clinic, Rochester, MN 55905, USA. edwardslab@mayo.edu
authors.forename: Albert O
authors.initials: AO
authors.lastname: Edwards
authors.forename: Dequan
authors.initials: D
authors.lastname: Chen
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Fridley
authors.forename: Katherine M
authors.initials: KM
authors.lastname: James
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Wu
authors.forename: Goncalo
authors.initials: G
authors.lastname: Abecasis
authors.forename: Anand
authors.initials: A
authors.lastname: Swaroop
authors.forename: Mohammad
authors.initials: M
authors.lastname: Othman
authors.forename: Kari
authors.initials: K
authors.lastname: Branham
authors.forename: Sudha K
authors.initials: SK
authors.lastname: Iyengar
authors.forename: Theru A
authors.initials: TA
authors.lastname: Sivakumaran
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: Barbara E K
authors.initials: BE
authors.lastname: Klein
authors.forename: Nirubol
authors.initials: N
authors.lastname: Tosakulwong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008268:Macular Degeneration / Q000235:genetics*; D008875:Middle Aged; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D051193:Toll-Like Receptors / Q000235:genetics*
chemical_list: D051193:Toll-Like Receptors