Fetal DNA Analyzed in Plasma from a Mother’s Three Consecutive Pregnancies to Detect Paternally Inherited Aneuploidy

Abstract

The recent demonstration of fetal DNA in maternal plasma and serum at concentrations much higher than those present in the cellular fraction has introduced new possibilities for noninvasive prenatal diagnosis of paternally inherited dominant disorders (1)(2)(3). To date, prenatal detection of fetal aneuploidy in maternal blood has focused on searching intact cells using fluorescence in situ hybridization. The use of fetal DNA in maternal plasma to determine fetal aneuploidy has rarely been described. We previously reported prenatal detection of a paternally inherited fetal aneuploidy from fetal DNA in maternal plasma (4). Here we report the application of such a technique in an additional case involving a mother’s three consecutive pregnancies. We studied fetal DNA in maternal plasma from a pregnant woman whose fetuses possibly had paternally inherited aneuploidy. Her husband had a balanced reciprocal translocation between the long arm of chromosome 10 and the short arm of chromosome 22, 46,XY,t(10;22)(q24.1;p11.2). The woman’s karyotype was normal. During her first pregnancy, genetic amniocentesis was performed at 19 weeks of gestation, and the maternal blood sample was collected at 22 gestational weeks before termination of the pregnancy. In contrast, during her second and third pregnancies, the …