Background: Results are presented from a nested association study of the complement factor H (CFH) gene region using a novel methodology which employs a high resolution genetic linkage disequilibrium map to estimate a point location for a causal mutation.
Methods: Age-related macular degeneration (AMD) case-control data from a genome wide single nucleotide polymorphism (SNP) panel were used to identify the target interval to be genotyped at higher density in a second independent panel. The pattern of linkage disequilibrium (LD) and segmental duplications across this region are described in detail.
Results: Our data are consistent with other studies in that strong association between the Y402H variant and AMD is observed. However, composite likelihood analysis which combines association data from all SNPs in the region, and uses genetic locations on a high-resolution LD map, gives a point location for a causal variant between exons 1 and 2 of the CFH gene.
Conclusions: Our findings imply that, in addition to the widely described Y402H variant, there is at least one and, most likely, several other mutations in the CFH gene which determine disease manifestation in AMD.
- linkage disequilibrium mapping