DNA fingerprints: the importance in forensic medicine. II. The significance of examining DNA polymorphisms of placental tissues for the purpose of paternity determination during the early stages within the first trimester.

Investigation of genomic polymorphisms detected by a minisatellite named tentatively "Myo", which is expected to correspond to the minisatellite in human myoglobin gene of Jeffreys et al., gives distinct and different aspects of chorionic villus and the decidual membrane in the same placenta. The chorionic villus, which is regarded as the extraembryonal tissue, represents the essential embryonal DNA fingerprint pattern, while the decidual membrane reveals the maternal one. A comparison between the DNA fingerprints from the chorion villus and from the blood sample of the suspected father provides the possibility of setting a paternity determination which can be achieved during the first trimester of a pregnancy.