The University of Iowa (UIHC)
Department of Pathology
LABORATORY SERVICES HANDBOOK


MCP CD46 (Renal Genetic Test)
Order Code: MCPCD46
Epic Lab Code: LAB7299
Order Form: A-1a Miscellaneous Request or Epic Req
  Commercial "Mail-out" Laboratory
6240 RCP
356-3527
Specimen:
Whole Blood
Collection Medium:
or
Pink top tube (EDTA sprayed) Lavender top tube (EDTA)
Minimum:
Preferred Minimum:  8 mL whole blood
Absolute Minimum:  4 mL whole blood
Analytic Time:
3 months
Reference Range:
None detected
Interpretive Data:
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%.
Comments:
Please print, complete and submit the Kidney Testing Requisition 
from the Molecular Otolaryngology & Renal Research Laboratory, to 
Specimen Control/Mailouts with the specimen and the Epic Requisition.
Methodology:
Oligonucleotide primers have been designed to amplify each exon of MCP.  
Because MCP contains many non-disease causing polymorphisms, it is 
sequenced directly using overlapping primer sets.
CPT Code:
83891, 83894, 83898 (x13), 83904 (x13), 83912

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Updated: 11/13/2009

Note: The information contained in this handbook is for use by personnel of University of Iowa Health Care. No other use is implied or intended.