Sequenom, Inc. announced the launch of the SensiGene Fetal RHD Genotyping test by Sequenom's CAP accredited and CLIA-certified laboratory, Sequenom Center for Molecular Medicine (Sequenom CMM). This is the company's first laboratory developed test powered by its SEQureDx technology.
In the United States, there are approximately 528,000 pregnancies in Rhesus D (RhD) negative women every year, and almost all of these women could benefit from an assessment of the RhD type of the foetus. RhD type can be determined by an invasive procedure, such as amniocentesis or chorionic villus sampling (CVS), but both procedures involve risk to the foetus. Currently in the United States, most RhD negative women are managed without knowing the fetal RHD status.
The benefits of the noninvasive SensiGene Fetal RHD Genotyping test include: Aid to physicians in creating a more informed strategy to manage the care of pregnant RhD negative women; Reduction in need for invasive procedures, such as amniocentesis or CVS; First trimester detection; Fetal identifiers - a control to confirm the presence of fetal DNA thus ensuring that a RHD negative result for a female foetus is due to the measurement of fetal rather than maternal nucleic acid in the sample.
"The introduction of this test is an important development in improving patient care for pregnant women in both the United States and in Europe," said Dr. Wolfgang Holzgreve, director at the University Hospital, Freiburg and Sequenom clinical advisory board member. "Fetal RHD genotyping utilizing real-time PCR has been widely used in Europe for over a decade, and has led to better patient management and is even considered for reduction of unnecessary treatment with Anti-D immune globulin. Based upon Sequenom's validation study, the SensiGene Fetal RHD Genotyping test appears to offer a higher level of sensitivity and specificity compared with the real-time PCR methodology."
"Launching the first test based on our SEQureDx technology is an important milestone for Sequenom and our CLIA lab - the Sequenom Center for Molecular Medicine," stated Shawn M. Marcell, vice president, molecular diagnostics. "We believe this test represents a significant and important advancement for prenatal care. Our ability to launch this test and bring it to patients is, in no small part, directly related to the strong support of the Fetal Medicine Foundation, UK, which supplied clinical samples to us."
The new SensiGene Fetal RHD Genotyping test is designed to detect circulating cell-free fetal (ccff) DNA from maternal blood and examine multiple regions of the gene that are known to be the most common genetic basis of RhD negative phenotypes. The test interrogates four targets within three exons located on the RHD gene on 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 foetuses. A quality control metric is also included to ensure detection of DNA. A fetal identifier control is further employed as a reflex control assay that detects fetal DNA in a sample within a large background of maternal DNA. The test is performed on Sequenom's proprietary MassARRAY system, which allows direct mass measurement of nucleic acids.
During the development course of feasibility, optimization, verification and validation more than 500 clinical samples were tested. The final blinded validation study, in which over 200 samples were evaluated, was performed in conjunction with the Fetal Medicine Foundation, and un-blinding was performed by Dr. Arnold Cohen, chairman of obstetrics and gynaecology at the Albert Einstein Medical Center, in Philadelphia. In this validation study the SensiGene Fetal RHD Genotyping test demonstrated: Sensitivity of 97.2% (92.9% - 98.9%) at a 95% confidence interval; Specificity of 96.9% (89.5% - 99.2%) at a 95% confidence interval.
"Successfully completing the fetal RHD genotyping validation study is a major achievement for our CLIA-certified laboratory," said Allan Bombard, MD, chief medical officer of Sequenom. "Our fetal RHD genotyping test, with the significant clinical improvement of first trimester detection, compared to current standard of care in the US, should become an important tool for the Ob/Gyn community. The ability to test for RhD incompatibility earlier in pregnancy than is currently possible, with potentially greater accuracy, is noteworthy."
People have one of four blood types, A, B, AB or O. Each of these is further classified according to the presence or absence of Rh factor proteins on the surface of one's red blood cells, which carry the Rhesus antigens. One of the main antigens is D. Those positive for the D protein are called RhD positive; absent the D protein one is RhD negative. About 85% of Caucasians are RhD positive, while 92-98% of African American and Hispanic populations and 98-99% of Asian and Native American populations are RhD positive. Between half and all the children born to an RhD negative mother and RhD positive father will be RhD positive.
RhD incompatibility in pregnancy occurs when the mother is negative for the Rhesus D factor and the baby is positive. During pregnancy the baby's blood cells may enter the mother's bloodstream causing the mother to produce antibodies that destroy and eliminate the baby's red blood cells. This immune response may lead to RhD disease. RhD disease can result in jaundice, anaemia, brain damage, heart failure or even fetal death. Without treatment, severe cases may result in stillborn deliveries.
Sequenom, Inc. s a life sciences company committed to improving healthcare through revolutionary genetic analysis solutions. Sequenom develops innovative technology, products and diagnostic tests that target and serve discovery & clinical research, and molecular diagnostics markets.