title: The relationship between BCMO1 gene variants and macular pigment optical density in persons with and without age-related macular degeneration.
abstract: BACKGROUND
  Recent evidence indicates that gene variants related to carotenoid metabolism play a role in the uptake of macular pigments lutein (L) and zeaxanthin (Z). Moreover, these pigments are proposed to reduce the risk for advanced age-related macular degeneration (AMD). This study provides the initial examination of the relationship between the gene variants related to carotenoid metabolism, macular pigment optical density (MPOD) and their combined expression in healthy humans and patients with AMD.
  
  
  METHODS
  Forty-four participants were enrolled from a general population and a private practice including 20 healthy participants and 24 patients with advanced (neovascular) AMD. Participants were genotyped for the three single nucleotide polymorphisms (SNPs) upstream from BCMO1, rs11645428, rs6420424 and rs6564851 that have been shown to either up or down regulate beta-carotene conversion efficiency in the plasma. MPOD was determined by heterochromatic flicker photometry.
  
  
  RESULTS
  Healthy participants with the rs11645428 GG genotype, rs6420424 AA genotype and rs6564851 GG genotype all had on average significantly lower MPOD compared to those with the other genotypes (p<0.01 for all three comparisons). When combining BCMO1 genotypes reported to have "high" (rs11645428 AA/rs6420424 GG/rs6564851 TT) and "low" (rs11645428 GG/rs6420424 AA/rs6564851 GG) beta-carotene conversion efficiency, we demonstrate clear differences in MPOD values (p<0.01). In patients with AMD there were no significant differences in MPOD for any of the three BCMO1 gene variants.
  
  
  CONCLUSIONS
  In healthy participants MPOD levels can be related to high and low beta-carotene conversion BCMO1 genotypes. Such relationships were not found in patients with advanced neovascular AMD, indicative of additional processes influencing carotenoid uptake, possibly related to other AMD susceptibility genes. Our findings indicate that specific BCMO1 SNPs should be determined when assessing the effects of carotenoid supplementation on macular pigment and that their expression may be influenced by retinal disease.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia ; School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia ; Queensland Eye Institute, Brisbane, QLD, Australia.
authors.forename: Beatrix
authors.initials: B
authors.lastname: Feigl
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia ; School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: C Phillip
authors.initials: CP
authors.lastname: Morris
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia ; School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: Joanne
authors.initials: J
authors.lastname: Voisey
authors.affiliation: Queensland Eye Institute, Brisbane, QLD, Australia ; Faculty of Health Sciences, University of Queensland, Brisbane, QLD, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Kwan
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia ; School of Optometry and Vision Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Zele
mesh_terms: D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D065348:Macular Pigment / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D050559:beta-Carotene 15,15'-Monooxygenase / Q000235:genetics*
chemical_list: D065348:Macular Pigment; C493358:BCO1 protein, human; D050559:beta-Carotene 15,15'-Monooxygenase