|January 2007 · Vol. 19, No. 01
UPDATENEW DEVELOPMENTS THAT ARE CHANGING PATIENT CARE
“Molecular karyotyping” opens a new avenue of prenatal diagnosis
Five years from now, look for array CGH to provide:
So-called copy number polymorphisms are common in molecular karyotyping but often of no clinical significance
An imbalance in the genome of the fetus may play a larger role than we’ve thought in 1st-trimester loss
Medical Director, Center for Fetal Medicine, Brigham and Women’s Hospital, and Associate Professor and Division Director, Maternal-Fetal Medicine and Reproductive Genetics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston
Prenatal diagnosis became a reality almost 40 years ago, when advances in microscopy and cell culture made it possible to examine chromosomes in fetal cells drawn from amniotic fluid—the familiar karyotype analysis. Technical advances continue to sharpen the resolution of routine karyotype analysis on amniotic fluid or a specimen of chorionic villus, and to raise the level of detail obtained from such a study.
Yet examining chromosomes by light microscopy remains time- and labor-intensive. A cell culture typically requires 2 weeks before growth of cells is sufficient to undertake a karyotype analysis—after which the microscopic evaluation requires further time and significant skill to perform.