USA Today takes a look at the rapid uptake of chromosomal microarrays for prenatal testing, noting that while the approach can detect more genetic abnormalities than current methods like karyotyping, the significance of many of these variants is often unknown.
"Our capacity to test and our capacity to make sense of the results are not well-aligned," Rachel Grob, the author of a book on prenatal and neonatal genetic testing, tells the paper.
David Kronn, chief of medical genetics at Maria Fareri Children's Hospital, agrees, noting that chromosomal arrays are a "powerful technique, but sometimes we don't know what the information means."
As reported in Daily Scan's sister publication Genome Technology this month, some geneticists say the challenges related to variants of unknown significance may hamper adoption of chromosomal arrays. Dom McMullan, head of molecular cytogenetics at the West Midlands Regional Genetics Laboratory in Birmingham, UK, tells GT that many UK labs are limiting the use of CMAs to pregnancies with an abnormal ultrasound scan.
"Reporting findings of unclear clinical significance has been a difficult area since the introduction of prenatal diagnosis by chromosome analysis," McMullan says. "It is not really a new problem, just likely to be more common with use of arrays and at a different level of resolution."
There are efforts to address these challenges, however. In particular, groups like the International Standards for Cytogenomic Arrays consortium and the Cytogenomics Array Group are developing databases to house new findings that can be shared among geneticists.