Office of Technology Development (OTD)

Aoy Mitchell, PhD

About 6.4 million women become pregnant in the U.S. each year, and about 70% of those women have maternal serum screening and/or an ultrasound test in an attempt to determine risks for common birth defects, such as those resulting from 10 trisomy 13, 18, and 21 (Down Syndrome). The best current non-invasive tests lead to a false positive rate between 7 and 20%. This high false positive rate has two consequences for American families and society. First, amniocentesis can carry a fetal loss rate of 0.5-1.0%. Second, the high false positive rate of non-invasive testing heightens maternal anxiety and stress in the large and fixed proportion of pregnant American women who receive false positive results.

Both the sensitivity and specificity of common non-invasive screening tools are extremely poor. The best current non-invasive tests lead to a false positive rate between 7 and 20%. This high false positive rate has two catastrophic consequences for American families and society. First, it creates the requirement for the two invasive diagnostic tests: chorionic villus 15 sampling (CVS) and amniocentesis, which each carry a fetal loss rate of 0.5% -1 %. Second, the high false positive rate heightens maternal anxiety and stress in the large and fixed proportion of pregnant American women who receive false positive results.

A diagnostic method using DNA present in the mother’s blood with an expected detection rate of about 99% and expected 0% false positive rate. Simple modification to off-the-shelf equipment and reagents are used for the diagnostic test. Unique primers, established as part of this intellectual property, are required to achieve results for the diagnostic test.

• Expected 99% detection rate
• Expected 0% false positives
• No danger to or loss of fetus
• Stress free testing for Down Syndrome

A method that allows the accurate detection and quantification of fetal DNA in maternal serum has been developed. The method is being expanded for comprehensiveness and development in a high-throughput setting.