RhCc Antigen (RHCE) Genotyping
0050421
Ordering Recommendation
Assess risk for alloimmune hemolytic disease of the newborn. Test may be ordered for parental or fetal genotyping.
Mnemonic
RH C
Methodology
Polymerase Chain Reaction/Fluorescence Monitoring
Performed
Tue, Thu, Sat
Reported
2-7 days  
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
  
Collect
Fetal Genotyping: Amniotic fluid OR two T-25 flasks at 80 percent confluency of cultured amniocytes. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787.
WITH Maternal Cell Contamination Specimen
 (see Remarks): Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Parental Genotyping:
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Amniotic Fluid: Transport 10 mL unspun fluid. (Min: 5 mL)
Cultured Amniocytes:
Fill flasks with culture media. Transport two T-25 flasks at 80 percent confluency of cultured amniocytes filled with culture media. Backup cultures must be retained the client's institution until testing is complete.
Maternal Cell Contamination Specimen:
Transport 3 mL whole blood (Min: 1 mL)
Whole Blood (Parental Genotyping):
Transport 3 mL whole blood. (Min: 1 mL)  
Storage/Transport Temperature
Amniotic fluid: Room temperature.
Cultured Amniocytes:
 CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to liability of cells.
Whole Blood or Maternal Cell Contamination Specimen:
 Refrigerated.  
Unacceptable Conditions
  
Remarks
Maternal specimen is recommended for proper test interpretation if contamination of the fetal specimen from the mother is suspected. Order Maternal Cell Contamination. Patient History Form is available on the ARUP website or by contacting ARUP Client Services.  
Stability
Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Whole Blood or Maternal Cell Contamination Specimen:
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
By report  
Interpretive Data
Background Information for RhCc Antigen (RHCE) Genotyping
Characteristics:
Fetal or neonatal alloimmune hemolytic disease, erythroblastosis, hydrops
Incidence:
13 percent of hydrops fetalis is caused by antigen-antibody mediated red cell hemolysis.
Inheritance:
Autosomal recessive.
Cause:
Maternal-Fetal Rh C/c antigen incompatibility.
Polymorphisms Tested: c.48C>G (p.W16C); c.201A>G (p.S67S), c.203A>G (p. N68S) and an intron 2 insertion.
Clinical Sensitivity: Unknown.
Methods:
PCR of exons 1 and 2 and intron 2 of RHCE gene followed by fluorescent monitoring.
Analytic Sensitivity and Specificity:
98 percent.
Limitations:
Bloody amniotic fluid specimens may give false-negative results because of maternal cell contamination; specificity may be compromised by mutations in primer sites or those outside the RHCE exons examined; fetuses predicted to be unaffected should continue to be monitored by noninvasive means. Diagnostic errors can occur due to rare sequence variations.

For quality assurance purposes, ARUP Laboratories will confirm the above result at no charge following delivery. Order Confirmation of Fetal Testing and include a copy of the original fetal report (or the mother's name and date of birth) with the test submission. Please contact an ARUP genetic counselor at (800) 242-2787 extension 2141 prior to specimen submission.

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc..



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS  
Note
For the Delta OD 450 nm, refer to Amniotic Bilirubin Scan (0080276).
CPT Code(s)
81479
Components
Component Test Code*Component Chart Name
0050421RhCc Antigen (RHCE) Genotyping
0051761RhCc Antigen (RHCE) Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • RHCE genotyping