Deletion of the CFHR-1 and CFHR-3 genes decreases the risk of immunoglobulin A nephropathy and AMD (23, –, 26) but predisposes to systemic lupus erythematosus and atypical hemolytic uremic syndrome (aHUS), a form of thrombotic micoangiopathy leading to end-stage renal failure (27). This evidence concerns the gene CFHR3 and atypical hemolytic-uremic syndrome.