Mar 13, 2014 – CF-DNA

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Health newsfeed for Thursday, March 13, 2014

ANCHOR LEAD:  TESTING MATERNAL BLOOD HELPS IDENTIFY GENETIC ABNORMALITIES IN THE BABY, ELIZABETH TRACEY REPORTS

A method for analyzing the mother’s blood for pieces of DNA shed by her fetus has been validated as more accurate in predicting genetic abnormalities than existing methods, a study in the New England Journal of Medicine concludes.  Michael Klag, dean of the Johns Hopkins Bloomberg School of Public Health, explains that the test can identify aneuploidy, where abnormal numbers of chromosomes are present.

KLAG: What we care about in clinical practice is predictive value.  If this test is positive how likely is it that the woman has an aneuploid pregnancy?  If it’s negative how likely is it that the woman has a normal pregnancy?  The results were remarkably better for this than for standard, that if a woman has a positive test for trisomy 21 she has a 45% chance of having an abnormal fetus.  The converse is true though, that a 60% chance exists that its normal.  So this is not a diagnosis it’s truly a screening test.  :30

Confirmation with additional assessments follows.  At Johns Hopkins, I’m Elizabeth Tracey.