CFHR1 and systemic lupus erythematosus: The absence of both copies of CFHR3 and CFHR1 is also associated with a lower risk of age-related macular degeneration (AMD) (Hughes et al., 2006) and IgA nephropathy (Gharavi et al., 2011), and a higher risk of atypical haemolytic uremic syndrome (aHUS) (Moore et al., 2010) and systemic lupus erythematosus (SLE) (Zhao et al., 2011).