STR typing of plasma DNA in a deficiency case of disputed maternity against a patient dying in the hospital.

In this deficiency duo case, the plasma that had been left over after clinical diagnostic tests was the only blood sample available from the deceased alleged mother. Since her blood had been ABO grouped during hospitalization, we tested the plaintiff for the ABO system first. Then, to draw as much genetic information as possible from their plasma, we phenotyped 13 plasma protein systems and, three and a half years later, analyzed three short tandem repeat (STR) loci. The conventional phenotyping and STR genotyping gave probabilities of maternity of 0.974 and 0.967, respectively, bringing the total probability to 0.999. The present study highlights the utility of plasma STR typing in case of need.