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SensiGene® Fetal RHD Genotyping
Early detection means better management.

The safe and accurate prenatal test for Rhesus D (RHD) status 

The SensiGene® Fetal RHD Genotyping test, developed and validated by Sequenom Laboratories, analyzes circulating cell-free fetal DNA extracted from a maternal blood sample. It is a noninvasive prenatal blood test to determine the fetal RhD genotype in RhD (-) mothers. The test can detect fetal RHD status as early as the first trimester (10 weeks gestation).

Clinical indications for testing

  • Identify RHD (+) fetus in RhD (-) mother.
  • Direct determination of fetal RHD status without testing the father.
  • Determine fetal RHD status when maternal anti-D titers are unclear.
  • Determine fetal RHD status in RhD(-) sensitized patients.

Clinical Data

The SensiGene Fetal RHD Genotyping test has demonstrated high accuracy, sensitivity and specificity.

  Performance n=199
Sensitivity >99.9% (95% CI: 97.3-100.0%)
Specificity 98.3% (95% CI: 91.0-99.7%)
PPV 99.3% (95% CI: 96.1-99.9%)
NPV >99.9% (95% CI: 93.1-100%)

Bombard AT, Akolekar R, Farkas DH, VanAgtmael AL, et al20. 

 

SensiGene Fetal RHD Genotyping is accurate across all trimesters.

SensiGene Fetal RHD Genotyping test results compared to cord blood phenotyping in newborns.

  1st Trimester Performance 2nd Trimester Performance 3rd Trimester Performance
Sensitivity 99% (95% CI: 93-100%) >99.9% (95% CI: 95-100%) >99.9% (95% CI: 95-100%)
Specificity >99.9% (95% CI: 90-100%) 97% (95% CI: 83-99%) 94% (95% CI: 80-99%)
Accuracy 99% (95% CI: 95-100%) 99% (95% CI: 95-100%) 98% (95% CI: 93-100%)

Moise KJ, Boring NH, O’Shaunessy R, et al21

 

No test is perfect.

The SensiGene Fetal RHD Genotyping test is a highly accurate, noninvasive test. However, false results may occur in rare cases.

Support

Our commitment to scientific integrity is matched only by our commitment to customer support.

Support

When you talk to someone at Sequenom Laboratories, you’re never talking to an outsourced contractor. Whether you're calling about billing, customer service, account management, or anything else, you’re talking to a Sequenom Laboratories specialist who is trained to help.

Education is critical to understanding the usage and benefits of our tests. Thus, we have an entire team of field specialists, medical science liaisons, and national account directors whose job it is to turn you and your staff into experts. We want to ensure that you have all the skills and knowledge you need to optimize your practice.

You will be faxed all results, whether positive or negative. We want to help you with how to best communicate with your patients, so our customer support team is available to answer questions about any test result.

Your Sequenom Laboratories Business Development Manager would be happy to provide you with information to share with your patients, or you can email us at support@laboratories.sequenom.com

Our commitment to you doesn’t end with the test. It begins there. We are committed to providing you with outstanding customer support in all areas, including:

  • Sample collection and logistics.
  • Billing services and reimbursement questions.
  • Genetic counselors to discuss test information and results with health care providers.

Contact our toll-free customer support line at (877) 821-7266.

Technology

Better results born of better science

Proprietary, noninvasive technology enables the detection and analysis of circulating cell-free fetal (ccff) nucleic acids (DNA) in a pregnant woman’s blood sample. Rather than harvesting placental tissue cells or entering the uterus to sample the amniotic fluid, circulating cell-free fetal nucleic acid can be obtained from maternal blood. 

Ccff DNA in maternal plasma is thought to derive from apoptosis of placental and fetal cells and possibly through the breakdown of fetal cells in circulation22 23 , 24.  Recent studies have shown >10% circulating fetal DNA concentration in maternal plasma9.

This test method is designed to detect circulating cell-free fetal DNA from maternal blood and examine multiple regions of the gene that is known to be the most common genetic basis of RhD negative phenotypes. The test interrogates targets within 3 exons located on the RHD gene in chromosome one. The test also incorporates male-specific targets on the Y chromosome because it has been demonstrated that Rh alloimmunization occurs more frequently in male fetuses23. There are quality control metrics added to the reaction to ensure accuracy and a quality control test is used to facilitate the distinction between maternal and female fetal DNA.

Summary of Test Design

This test detects targets within 3 exons of the RHD gene located on chromosome one.

Assay Targets: Exons 4, 5, 7

Psi (Ψ) pseudogene in exon 4

4 Assay Controls: 3 targets on Y chromosome (SRY, TTTY, DBY)

  •      Extraction Control (TGIF)
    • A positive control for successful DNA extraction must be detected to issue a report. Presence or absence of RHD exon targets determines if the specimen will be reported as RHD positive or negative.
    • All RHD negative results are confirmed on a second 4 mL aliquot of submitted plasma.
    • For specimens that generate a fetal RHD negative female result (and thus in need of differentiating mother and fetus), a fetal identifier (FI) control is performed to compare maternal and fetal genotypes.
    • In the FI control, 92 potentially informative DNA markers (single nucleotide polymorphisms) are examined for markers present in the fetal DNA fraction that are absent in the maternal genomic DNA fraction. These markers must therefore be paternally inherited. If six or more markers are observed, the RHD negative female result can be attributed to the true presence of fetal DNA.

 

 

Results Reporting

An easy-to-read one page lab reported will be faxed to your office.

Ordering

Accuracy made easy.

The SensiGene Fetal RHD Genotyping test is easy to implement in your office. 

  • Indicated for use in the 1st or 2nd trimester, >10 weeks’ gestation.
  • Simple collection of 2 x 10mL EDTA lavender top tubes of whole blood (kits provided).
  • Results turnaround in approximately 7 business days from receipt of the sample in the lab.
  • Affordable, patient-friendly billing policy and patient assistance program.

 

How do I get started? 

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Digital test requisition form (TRF) - for your convenience.

This digital TRF is provided for U.S. Physician Use Only.
[Note:  Use of this form requires you to have a Sequenom Laboratories account number and a provider collection kit(s) as a prerequisite].

If you are not currently a Sequenom Laboratories customer, please select the ‘CONTACT US TO ORDER’ button above. If you are an international distributor, please contact us at partnerships@sequenom.com

Sequenom Laboratories TRF