Abstract
Purpose: :
Age-related macular degeneration (AMD) is the most common cause of blindness in developed countries; several genes have been implicated in this complex disease. We recently identified the SERPING1 gene as being associated with AMD in a UK cohort, and replicated our result in a US cohort. The current study aims to comprehensively scan the region, rule out other genes and confirm SERPING1 as the most likely causal gene.
Methods: :
Previously 11 SNPs were genotyped across the gene, this study analyses a further 50 SNPs including 4 additional SNPs within the gene, 2 in the nearby TIMM10 gene, the expression of which has been shown to be associated with SNPs close to the SERPING1 gene, and 44 HapMap tagging SNPs. The region analysed was selected on the basis of linkage disequilibrium (LD), is 546 kilobase pairs and contains 21 genes (NCBI, 36.3). Association tests were conducted on all SNPs and haplotypes.
Results: :
The highest association with AMD remained in the SERPING1 gene, the most strongly associated SNP was rs2511989 (Χ218.4, corrected p 1.1E-03). No stronger association was identified in any of the adjacent genes. One haplotype containing the SERPING1 gene was found to be the most highly associated, however the result was only marginally more significant (Χ2 20.8, corrected p 2.0E-04) than the single SNP test, suggesting no extra information is gained from haplotype analysis in this case.
Conclusions: :
Other genes are ruled out by this high density scan of the region. This study confirms that rs2511989 is the strongest signal in the extended region, strongly implicating the SERPING1 gene.
Keywords: age-related macular degeneration • genetics