Abstract
Purpose: :
Genes related to inflammation and retinal disease have been associated with age-related macular degeneration (AMD). These genes have also been shown to interact with smoking to increase risk. This study examines single nucleotide polymorphisms (SNPs) in apolipoprotein E (APOE), complement component 2 (C2), complement factor H (CFH), C-reactive protein (CRP), and EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) in relation to AMD risk.
Methods: :
Prevalent AMD cases (n=218) and control subjects (n=218) were ascertained from the Los Angeles Latino Eye Study (LALES). AMD cases were identified by an age related eye disease study scale (AREDS) score ≥7. Controls had an AREDS score=0. Subjects were categorized as smokers if former or current smoking was reported during the study visit. Genotyping was carried out using the Illumina platform with tag SNPs selected to characterize ≥80% of the variation in each gene. Analyses were conducted assuming an additive model where the least frequent genotype conferred the greatest risk.
Results: :
After adjusting for age, 15 SNPs in APOE, C2, and CFH were nominally (p<0.05) associated with AMD. Of these, 6 appear to be protective and 9 increase risk. Interaction with smoking status yielded nominally significant associations with 11 SNPs in EFEMP1 and CFH of which 10 were protective. After correction for multiple comparisons no main effects or interactions remained significant.
Conclusions: :
Four of the genes examined reveal potential significant associations with AMD. Notably, many of these main effects and interactions appear to protect against the disease.
Keywords: age-related macular degeneration • genetics