Preferred Minimum: 8 mL whole blood Absolute Minimum: 4 mL whole blood

MCP (MCP) The MCP gene contains 14 exons that encode the 392 amino acid protein Membrane Cofactor Protein (MCP; CD46). MCP is a locally synthesized membrane bound complement regulator with co-factor activity for Factor I (CFI)-mediated cleavage of C3b and C4b. Over 30 mutations in the MCP gene have been identified in persons with aHUS. Mutation screening of MCP is indicated in persons with aHUS. Atypical Hemolytic Uremic Syndrome The clinical manifestations of hemolytic-uremic syndrome (HUS) include hemolytic anemia, thrombocytopenia and acute renal failure. Most cases are associated with epidemics of diarrhea caused by verocytotoxin-producing bacteria. Atypical hemolytic uremic syndrome (aHUS) is a rarer disease. It is not associated with Stx-HUS infection and neither does it present with watery, bloody diarrhea (Warwicker et al., 1998). It can be either sporadic or familial, and has an extremely unfavorable prognosis, with about 50% of persons progressing to ESRD and 25% dying during the acute illness; transplantation in many survivors is unsuccessful (Schieppati et al., 1992; Taylor et al., 2004). Genetic studies have shown that approximately 50% of cases of aHUS are caused by mutations in MCP, CFH and IF (Caprioli et al., 2006). Identifying the genetic cause of aHUS is extremely important as it can help to direct clinical treatment decisions. Sensitivity is greater than 99%.