In response to the recent launch of Sequenom's MaterniT21 test to detect trisomy 21 by sequencing maternal plasma, the International Society for Prenatal Diagnosis said that while the test is "not fully diagnostic" and "constitutes an advanced screening test," it nevertheless offers "substantial new opportunities to improve prenatal screening."
The ISPD "accepts that with suitable genetic counseling," a sequencing-based test "can be helpful for women who have been determined to be high risk," it wrote in a statement released on its website.
However, it advised that a positive result must still be confirmed with invasive methods such as amniocentesis or chorionic villus sampling.
Currently, the ISPD does not endorse the use of the test for women determined to be at low risk, nor does it endorse the use of the test outside of a protocol that considers the "overall best combination of tests, their impact on screening performance, and patient acceptability."
Additionally, it recommends that all women considering the test first receive genetic counseling, which should include providing the woman with information about the test's accuracy as well as the possibility of receiving a positive result and having to wait for further confirmatory test results. Genetic counseling should also inform women that the test only screens for Down syndrome, which constitutes about half of fetal aneuploidy, and cannot test for Mendelian disorders, microdeletion syndromes, or other syndromes.
The ISPD recommends that before the test is implemented on a broad basis outside of high-risk pregnancies, it would need to demonstrate efficacy in low-risk populations and in diverse populations such as twins and in vitro fertilization pregnancies. Additionally, it would have to show that when used with other tests, the results can be combined to provide a "composite risk estimate."
Analyst David Ferreiro of Oppenheimer wrote in a research note that the statement is "an early positive" for the MaterniT21 test, which was launched last week (CSN 10/19/2011).
Additionally, Ferreiro reiterated expectations that for 2012 and 2013, Sequenom would recognize revenue from the test only in high-risk populations, billing just over 10,000 tests in 2012 for $15.3 million in revenue and around 37,000 tests in 2013 for $55 million in revenue.