CFHR1 and age-related macular degeneration: Due to high population frequency and effect sizes, SNPs in the cluster of genes CFH-CFHR1-5 on chromosome 1, near the age-related maculopathy susceptibility 2 (ARMS2) and high-temperature requirement factor A1 (HTRA1) genes on chromosome 10 contribute nearly 80% of AMD's genetic risk6,9–11.