Would you want to know if your unborn baby is at risk of autism?
Researchers wrapping up a 4,406-patient study say that a new genetic test that analyzes fetal DNA in more detail than current prenatal tests, can detect additional abnormalities, including those associated with autism and other intellectual disabilities, making them a potentially more accurate way of predicting disease risk.
Chromosomal microarray analysis, which compares specific regions of an unborn baby’s DNA to that of a normal genome, should be offered to all expectant mothers, say researchers at Columbia University who led the study. The current method of prenatal testing for genetic diseases, known as karyotyping, involves a cruder analysis of DNA as it is packaged in chromosomes in fetal cells. Karyotyping can identify broad abnormalities such as changes in the number of chromosomes or structural aberrations; it is used to diagnose conditions such as Down syndrome, for example, which results from an extra chromosome. Microarray testing, which uses the same invasive methods as karyotyping — by sampling the chorionic villus cells from the placenta, or amniocentesis, which extracts cells and fetal DNA from amniotic fluid—can do that and more, says Dr. Ronald Wapner, director of reproductive genetics at Columbia University Medical Center and lead author of the study published in the New England Journal of Medicine.
“Karyotyping has been the gold standard for 60 years,” he says. “Microarray identifies everything a karyotype identifies and more, so why wouldn’t people want more information?The article merely describes current research and does not suggest that prenatal testing is in the near future. But the possibility of such a test, of course, could raise the issue of abortion.