Isolating Fetal Trophoblast Cells for Prenatal Genetic Diagnosis

Abstract

To the Editor. —The article by Drs Simpson and Elias 1 reviews the feasibility of using various candidate fetal cells (eg, trophoblast cells, lymphocytes, granulocytes, and erythroblasts) for prenatal genetic diagnosis. The authors consider isolation of trophoblast cells to be theoretically attractive, but stated that with regard to the use of monoclonal antibodies directed toward trophoblast, no further data have been presented since the original publication in 1990. 2 In our laboratory, monoclonal antibodies to trophoblast have been used in an immunomagnetic separation to isolate trophoblasts from maternal blood. Polymerase chain reaction analysis of the cell isolates correctly identified fetal sex in 13 of 14 cases. 2 The cell isolates were identified as syncytiotrophoblast in a morphological study. 3 More recently, further evidence was presented using polymerase chain reaction analysis to detect the paternally inherited allele for β-thalassemia in trophoblast isolates from maternal blood samples. 4 Inheritance was confirmed by