Scientists work on blood test to detect Down Syndrome

A CHEAP, safe blood test that can tell a woman if she is pregnant with a Down Syndrome baby is being developed by scientists.

Researchers hope it will offer a better alternative to invasive tests which rely on collecting samples of womb fluid or placental tissue.

So far the test has been shown to work in principle using a simplified version to identify DNA from the male Y chromosome.

In future, the same method is expected to detect the extra chromosome called “trisomy 21” that leads to Down Syndrome.

The test may also be refined to reveal two other chromosomal disorders, Patau and Edward’s Syndromes.

Scientists hope it will be available to clinics in two to five years time.

Dr Suzanna Frints, leading the research team at Maastricht University Medical Centre in the Netherlands, said: “It is inexpensive compared to the costs of invasive pre-natal diagnosis, and could easily be implemented costing between €30-150 per kit per person, with a small apparatus in every hospital in the world.

“I’d like all women to have the choice to be able to have this test.”

The technology, called “multiplex ligation-dependent probe amplification” (MLPA), is already widely used to detect chromosomal abnormalities in invasively obtained test samples.

However the new test is able to identify foetal DNA in blood. Results can be delivered in just 24 to 62 hours, Dr Frints told the annual meeting of the European Society of Human Reproduction and Embryology in Rome.

Currently pregnant women who suspect they might be carrying a Down Syndrome baby can have one of two invasive tests to provide a definite answer.

Amniocentesis involves inserting a needle and drawing off fluid from the amniotic sac enclosing the baby. For the other test, chorionic villus sampling, a fragment of the placenta is removed with forceps.

Both procedures carry a small risk of miscarriage.