Ordering Recommendation

Determine the number of copies of the RHD gene. Does not identify or distinguish between partial and weak RHD genotypes. A fetal sample is required for determination of fetal RHD genotype.

Mnemonic

RHD

Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Varies

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 Cultured amniocytes: Two T-25 flasks at 80 percent confluency.
OR cultured CVS: 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 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 amniotic fluid in a sterile container. (Min: 5 mL)
Cultured amniocytes AND cultured CVS: 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

Amniotic fluid, cultured amniocytes and cultured CVS: 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

Frozen specimens in glass collection tubes.

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

Amniotic fluid, cultured amniocytes and cultured CVS Fetal Specimen: 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

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the U.S. Food and Drug Administration. This test was performed in a CLIA- certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)

Note

Whole blood is acceptable for paternal specimens.

Hotline History

N/A

CPT Codes

81403

Components

Component Test Code* Component Chart Name LOINC
0050422 RhD Gene (RHD) Copy Number 35465-4
0051369 RhD Gene (RHD) Copy Number Specimen 66746-9
* 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

  • RHD Gene
  • RHD genotyping
RhD Gene (RHD) Copy Number