A child with Down's syndrome (C) participates in a performance during a humanitarian concert for children with Down's syndrome, (File)
A child with Down's syndrome (C) participates in a performance during a humanitarian concert for children with Down's syndrome, (File)

Researchers in Cyprus say a simple blood test can predict whether a baby is likely to be born with a form of mental retardation known as "Down syndrome." The breakthrough could put an end to risky tests that have been blamed for causing miscarriages in pregnant women.

After five-years of intensive research, doctors in Cyprus concluded that DNA differences between the mother and the fetus can accurately predict whether a fetus is at risk of developing Down syndrome.

The research was led by Dr. Philippos Patsalis, medical director of the Cyprus Institute of Neurology and Genetics. He said the new test could mean the end of existing invasive testing procedures.

"I think the breakthrough here is that we open up a new way of pre-natal testing," he said. "We are probably in the beginning of closing the chapter of invasive pre-natal diagnosis, which requires the introduction of a needle in the uterus and the collection of fetal cells, which is associated with 1-2 percent of spontaneous miscarriages.".

A procedure called amniocentesis is currently performed to determine if a baby is likely to be born with Down syndrome.  It is usually conducted at 16 weeks gestation and involves taking fluid from the amniotic sac surrounding the developing fetus by inserting a hollow needle into the mother's uterus.

Patsalis? says his method involves taking a small amount of fetal DNA from the mother?s blood during the tenth or eleventh week of her pregnancy to detect extra copies of chromosome 21 in the fetus.

"With the new tool you can only take 5 mili-litres of peripheral blood from the hand of a pregnant woman and can say with certainty, first about the Down syndrome and in the future about other genetic diseases," Patsalis explains. "Now the major advantages of this milestone are that the new tests are non-invasive, it will be offered potentially to all pregnant women, not only high risk, which means all pregnant women will have the opportunity to have this information about a healthy pregnancy or not."

In the initial, small trial of 40 pregnant women, researchers were able to correctly diagnose 14 cases of extra copies of the chromosome, and 26 normal fetuses, highlighting its clinical potential.

Patsalis says he hopes to have the test available to the public within two years. "This research took us five years, now we have to carry out a large clinical trial of 1,000 pregnancies to extract some further information and introduce these parameters in the test and then I believe in less than two years it will be available to the public," Patsalis states.

Patsalis said the new test will be affordable and the results can be obtained within 4-5 days.