To replicate the relationship of complement system variants with preeclampsia and to determine whether mutations in complement regulatory proteins are present in non-autoimmune patients with severe preeclampsia and/or HELLP, we screened 59 patients and 143 ethnically matched healthy controls with normal pregnancies from the Universal Samples Database at the University of Utah for mutations in MCP, CFI, and CFH. Here, CD46 is linked to preeclampsia.