Company Sequenom has launched the first commercial non-invasive prenatal test for trisomy 21 (Down’s Syndrome) in the US.
The MaterniT21 test will be available in 20 regions of the country, although access will be available only via doctors and not direct-to-consumers. The test is expected to cost around $1900, a similar cost to that of invasive testing, though women may be able to receive it via their health insurance.
The clinical validation study behind the new text has been simultaneously published in the journal Genetics in Medicine (see previous news), demonstrating a detection rate of 98.6% in women with high-risk pregnancies of 10-22 weeks’ gestation. At this stage, the non-invasive approach is unlikely to replace the ‘gold standard’ of invasive testing and karyotyping, doctors hope that it will reduce the number of high-risk women who undergo invasive testing unnecessarily.
Invasive testing has an associated risk of miscarriage, and currently results in the deaths of significant numbers of healthy fetuses, since the accuracy of Down’s Syndrome screening tests (to identify high-risk pregnancies) is not perfect. However, karyotyping does have the added benefit of diagnosing additional chromosomal abnormalities that may be present. The ideal product would be a highly accurate, non-invasive test for a range of serious chromosomal defects, but whilst this scenario may eventually be fulfilled, the science is not there yet.
Comment: The publication and product launch mean that Sequenom is currently the market leader in non-invasive testing despite a delay of more than two years beyond their original planned launch date. This followed retraction of previously published study data, apparently due to inaccurate reporting of results. However, rival offerings may be close behind; companies including Verinata Health and Gene Security Network are said to be planning to launch similar products next year.