New Less Invasive Down's Syndrome Test Created

Down's Syndrome, also known as Trisomy 21, is a genetic disorder caused by a third copy of the twenty first chromosome. Down's is generally associated with a decrease in cognitive function along with an impairment to physical development. Diagnostic tests have been available for years. The problem with these tests is that they carry a relatively high risk of miscarriage.  There are two main methods that are currently used; the first requires a drawing of amniotic fluid a carries a 1 in 100 chance of miscarriage. The second, which offers a worse 1 in 50 chance of miscarriage, utilizes chorionic villus sampling, taking a tissue sample from within the womb. 

Because of these high risks, a new method has been developed by Stanford University. This method requires just a blood sample from the mother. Known as a "shotgun sequencing test," the method sequences the mother's genes. DNA from the baby is found in the mother's blood through the placenta. The trial, which was done on 18 women was extremely successful, correctly identifying even the smallest amount of increase of the 21st chromosome.  The next step is a larger study but this method could easily be implemented in the next few years, allowing parents to know as soon as possible. 

BBC