Microarray Analysis May Add to Karyotyping for Prenatal Testing
(HealthDay News) – Microarray analysis can be a useful addition to karyotyping in prenatal testing and appears to be helpful in the investigation of stillbirth, according to two studies published in the Dec. 6 issue of the New England Journal of Medicine.
In the first study, Ronald J. Wapner, MD, from the Columbia University Medical Center in New York City, and colleagues compared standard karyotyping and chromosomal microarray analysis on fetal samples from 4,406 women who were undergoing prenatal testing. The researchers found that microarray analysis was successful on 98.8% of samples. Of 3,822 samples with a normal karyotype, microarray analysis showed genomic alterations in 2.5%. Microarray analysis showed alterations in 6.0% of fetuses with a structural abnormality and in 1.7% of women who had undergone testing due to advanced age or a positive screening result.
In the second study, Uma M. Reddy, MD, MPH, from the National Institutes of Health in Bethesda, MD, and colleagues compared karyotyping and single-nucleotide polymorphism array analysis using samples from 532 stillbirths. The researchers found that microarray analysis produced results significantly more often (87.4 vs. 70.5%) and detected genetic abnormalities significantly more often (8.3 vs. 5.8%). Microarray analysis was significantly better able to detect genetic abnormalities in antepartum stillbirths and in those with congenital anomalies.
"Both pretest and post-test counseling by trained genetics counselors and geneticists are critical," Lorraine Dugoff, MD, from the University of Pennsylvania in Philadelphia, writes in an accompanying editorial in reference to the first study. Regarding the second study, she suggests that "the identification of an abnormal result may provide comfort, end the search for a cause, and help with the assessment of risk and the development of a plan of care for future reproduction."
Authors from both studies disclosed financial ties to the biotechnology industry.