Abstract
Purpose: :
To investigate the relationship between macular pigment optical density (MPOD), and complement factor H (CFH) and/or LOC387715 genotype.
Methods: :
We recruited 270 healthy subjects for this study. Demographic and health details were recorded. MPOD was measured by heterochromatic flicker photometry (HFP) using the Macular Metrics DensitometerTM. Genotype data for each locus was downloaded from HapMap for the CEU population. Haploview was used to determine haplotypic structure and identify tagged SNPs across loci. SNaPshot (ABI) primer and probe combinations were identified and synthesized for each locus. The following SNP sites were assessed: CFH- rs419137, rs6677604, rs2284664, rs3753396, rs1061170, rs800292; LOC387715- rs10490924, rs2736911, rs10490923. Genotyping was performed using SNaPshot assays on an ABI 3100 genetic analyser. Some samples were replicated to assess accuracy of genotype calling.
Results: :
More than 90% of subjects with family history of AMD had at least one CFH Y402H variant allele; 65.4% of subjects with no family history had at least one CFH Y402H variant allele. This difference was statistically significant (contingency table chi-square test, p<0.001). Nearly 51% of subjects with a family history of AMD had at least one LOC387715 variant allele, compared with 37.2% of subjects with no family history (borderline significant, contingency table chi-square test, p=0.053). Controlling for age, BMI, dietary lutein and zeaxanthin, sex, smoking, and family history, no direct relationship was found between MPOD and either CFH or LOC.
Conclusions: :
Family history of AMD is strongly associated with presence of the CFH Y402H variant allele, and marginally associated with the LOC 387715 allele. There does not appear to be a relationship between either of these AMD risk alleles and MPOD. However, we await further genotype results, and analysis of a larger subject population.
Keywords: macular pigment • age-related macular degeneration • genetics