Problems of Forensic Sciences 2006 Vol. 67 (LXVII) 273-278
EFFECT ON PATERNITY INDEX OF SUBSTITUTING A BROTHER FOR THE TRUE FATHER
Jarosław BERENT, Renata JACEWICZ, Stefan SZRAM
Department of Forensic Medicine, Medical University, Łódź, Poland
Streszczenie
In the analysis of trios with the true father, inconsistencies never appear (if the effect of a possible mutation is excluded). The Paternity Index (PI) calculated for such trios always has a value greater than zero. If in such a trio the true father is replaced by his brother, it can cause a change in the PI if the brother’s genotype is different from the genotype of the true father. The purpose of this study was to determine what effect replacing the true father in a trio with his brother has on the PI value for that trio. In the study a computer simulation was run on all theoretically possible trios with the true father and his brother. For all the simulated trios PI values were calculated and compared. The calculations were based on hypothetical systems made up of equally frequent alleles, and real systems from SGM Plus multiplex. The analysis confirmed that replacing the true father in a trio with his brother, if no inconsistency appears as a result, does not cause any change in PI values in the majority of cases. Thus, distinguishing the true father from his brother can be achieved practically only by means of excluding the brother.
Słowa kluczowe
Forensic genetics; Paternity Index; Avuncular Index; Relatives; SGM Plus multiplex.