Prenatal determinations of paternity by molecular genetic "fingerprinting".

Clinical situations that require determining the paternity of a fetus are diagnostic dilemmas. Numerous technical problems have significantly hampered the ability to make accurate predictions on tissues obtained early in gestation. Applying the technique of molecular genetic "fingerprinting" in two gestations in which parentage was uncertain, we found that paternity can be established readily using DNA obtained from amniocytes or chorionic villi. The accuracy of this method exceeds that of conventional protein-based assays and is not decreased by variations in gene expression. Multiple analyses can be performed on restriction endonuclease digests of DNA present in very small amounts of cellular material normally obtained by routine prenatal diagnostic techniques. The simplicity, speed, reliability, and accuracy of molecular genetic analysis make it ideally suited to address questions of familial relationship in the prenatal period.