Ordering Recommendation

Assess risk for alloimmune hemolytic disease of the fetus and newborn (HDFN) or hemolytic transfusion reaction. May be ordered for parental or fetal genotyping. 

Mnemonic

RHC GENO

Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Varies

Reported

3-10 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Fetal genotyping: Amniotic fluid.
OR Cultured amniocytes: Two T-25 flasks at 80 percent confluency. 
If the client is unable to culture, order test Cytogenetics Grow and Send (ARUP test code 0040182) in addition to this test and ARUP will culture upon receipt (culturing fees will apply).  If you have any questions, contact ARUP's Genetics Processing at 800-522-2787 ext. 3301.
WITH maternal cell contamination specimen
(see Note): Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).
Parental genotyping:
Lavender (K2EDTA), Pink (K2EDTA)

Specimen Preparation

Amniotic fluid: Transport 10 mL amniotic fluid in a sterile container. (Min: 5 mL).
Cultured amniocytes: Transport two T-25 flasks at 80 percent confluency filled with culture media. Backup cultures must be retained at 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

Cultured amniocytes: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to lability of cells.
Whole blood or maternal cell contamination specimen:
Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin tubes.

Remarks

Patient History Form is available on the ARUP website or by contacting ARUP Client Services.

Stability

Fetal specimens: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Whole blood or maternal cell contamination specimen:
Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month

Reference Interval

By report

Interpretive Data

Refer to report

Compliance Category

FDA

Note

Maternal specimen is recommended for proper test interpretation if contamination of the fetal specimen from the mother is suspected. Order Maternal Cell Contamination.

Hotline History

N/A

CPT Codes

0001U

Components

Component Test Code* Component Chart Name LOINC
3002016 RHC GENO Specimen 31208-2
3002017 RhCc Genotype 46731-6
* 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
RhC/c (RHCE) Antigen Genotyping