Sequenom Mulls Change to Down Syndrome Test

Since then, Stylli has been speaking to investors in order to assuage any worries and to explain the advantages of the choosing the DNA-based test over one which relies on RNA.

"The data we've collected to date [on the DNA-based test] is extremely good. You can't tell the difference with the RNA test," he says, referring to its accuracy in detecting Down syndrome.

The DNA-based test is superior to the RNA-based test because it reduces the rate of "no calls" -- or inconclusive results -- for Down syndrome and is able to detect other genetic abnormalities such as Edwards syndrome and Patau syndrome, Stylli adds.

So far, whatever Stylli is saying to investors appears to be working. Since closing Friday at $13.86, Sequenom shares have risen steadily and are up 20% to $16.69 in recent trading.

To date, Sequenom has used the DNA test to analyze 359 blood samples from pregnant woman; another 500 to 1,000 samples will be tested before the DNA-based Down syndrome test is ready for a commercial launch.

If Sequenom can't get this new work done in time for a summer launch, or if the data, once analyzed, reveal a problem with the DNA test, Sequenom may come to regret its decision to switch tests so suddenly.

Down syndrome occurs when a baby has three copies of chromosome 21 instead of the normal two copies. Babies born with Down syndrome grow up with developmental and mental disabilities and abnormal facial appearances.