CFHR1 and age-related macular degeneration: To assess the combined effect of variants at the CFH locus, we carried out association analyses of the haplotypes formed by the seven CFH variants considered in our study with AMD and FHR-4/FH levels; we included rs6677604 as proxy for the CFHR1–3 deletion29 to assess its influence on FHR-4/FH levels.