PROCESS FOR THE PRENATAL DIAGNOSIS OF GENETIC ABNORMALITIES

摘要

PROCESS FOR THE PRENATAL DIAGNOSIS OF GENETIC ABNORMALITIES It has been possible to demonstrate clearly both in umbilical cord blood samples and after the separation of pregnancy blood that the combination of the triple gradient and MACS with anti-CD71 marked cells is a very effective method of enriching nucleated erythrocytes. The proportion of nucleated erythrocytes in the umbilical cord blood was between 72 and 89% after both enrichment methods. It has been possible to detect nucleated erythrocytes in the positive fraction according to the triple gradient and MACS in all cases in pregnant women at various gestation stages. The variation in the number of enriched nucleated erythrocytes in various pregnancies very probably reflects individual differences in the foeto-maternal cell ratio at various stages in pregnancy. The process described here makes it possible in normal male blood and that of nonpregnant women to demonstrate no nucleated erythrocytes, by contrast with pregnant women at various stages of gestation. The method is also highly reproducible and suitable for clinical diagnosis. With fluorescence in situ hybridisation it has been possible to detect a foetal trisomia in all three cases investigated. The enrichment of nucleated erythrocytes is thus strong enough to diagnose infantile aneuploids using fluorescence in situ hybridisation. It is therefore obvious that it is possible with this only slightly invasive and relatively simple and economical method to conduct screening examinations for three of the most important trisomias (13, 18 and 21) and monogenic diseases (with the aid of the PCR) with virtually no risk to the patient and the child.