A Bit Clearer

At the Society for Maternal-Fetal Medicine meeting this week, Columbia University Medical Center's Ronald Wapner presented his finding that chromosomal microarrays are more powerful than karotypes are for detecting fetal anomalies. "With karyotyping, we can see only when pieces of the genome of about 5 million base pairs are missing from a chromosome. With CMA [chromosomal microarray], we can see missing pieces of fewer than 100,000 base pairs," Wapner said in a statement. His study included more than 4,000 participants. Their blinded samples were split up and sent to one of four labs for chromosomal microarray analysis and to another lab for standard karyotyping. "For prenatal testing, karyotyping and CMA are equally effective in identifying aneuploidy. Microarray detects additional clinically relevant information both in cases with structural anomalies and in those sampled for routine indications," Wapner reported in his meeting abstract.