Researchers have come up with a new DNA test that helps detect Down Syndrome and other diseases more accurately in foetus compared to the standard procedures followed at present.
The results are also available in around 9-10 weeks, which is earlier than the time taken for the traditional method. This also gives mothers more time to decide about whether to continue or abort the foetus.
In the DNA test, a sample of mother's blood is taken followed by testing the DNA coming off the placenta. The DNA sequence is then compared to the normal chromosome counts for its respective stage of pregnancy.
Diana W. Bianchi led a team of researchers, MD; Executive Director of the Mother Infant Research Institute at Floating Hospital for Children located at Tufts Medical Center said, 'We found that the major advantage of non-invasive prenatal DNA testing was the significant reduction of the false positive rate. The test could eliminate the need for many of the invasive diagnostic procedures such as amniocentesis."
In case of Down Syndrome, the new test resulted in only six false positive cases, whereas for the old test the figure stood at 69.
The DNA test uses the mother's plasma cell-free DNA and thus it is 10 times more accurate, thus reducing the rate of false alarm. This also avoids the need of the next step, the invasive amniocentesis test, which gives more positive result, but can lead to miscarriages also.
Down Syndrome is a genetic disorder which causes physical growth delays and mild to moderate intellectual disability. The study was published in New England Journal of Medicine.
But at present, the cost of the DNA test is between $1,200 and $2,700, while the traditional tests range from $200 to $300. The research can throw open a new market for biotechnology firms. The new test can be a boon for mothers at high risk, including those over 35 years.