Mutations in Complement Genes Increase Risk for aHUS.

A single mutation in the CFH, C3, or CFB complement genes conferred an increased risk of atypical hemolytic uremic syndrome (aHUS) in a recentJASN study of 795 aHUS patients and their relatives. Also, a mutation in theMCP or CFI complement genes in combination with mutations in other complement genes significantly increased aHUS risk, and 50% of patients with a combination of mutations in MCP and other complement genes developed kidney failure within 3 years of aHUS onset. Those with a combined MCP mutation were also more likely to experience disease recurrence after a kidney transplant.