Disclosed are screening methods for determining a human subject's propensity to develop a vascular disorder and/or age-related macular degeneration (AMD), therapeutic or prophylactic compounds for treating disease or inhibiting its development, and methods of treating patients to alleviate symptoms of the disease, prevent or delay its onset, or inhibit its progression. The inventions are based on the discovery that persons with a genome having a deletion of the CFHR-1 and/or CFHR-3 gene, which normally lie on human chromosome 1 between DNA encoding CFH and CFHR-4, are at reduced risk of developing AMD, and elevated risk of developing vascular disease such as aneurysm.
