Paternity index (PI) vs. residual PI in real cases. Inferences about Exclusion Power and real exclusion rates over 11 STR polymorphic systems in Entre Ríos population in Argentina

Abstract Eleven polymorphic systems were analysed in 107 trios comprising the alleged father, mother and child. PI, Residual PI (RPI), and the respective distribution descriptive parameters were obtained. In cases in which the exclusion of paternity was determined, the exclusion percentage was evaluated for each system and was compared with the calculated Exclusion Power. Only three PI values were observed to be inside the RPI value curve, although this only occurs for 2.5% of cases. Like other authors regarding other populations, we conclude that in this population, more polymorphic systems must be analyzed when PI values under 1000 are observed. Total Exclusion Power for this polymorphic system was 0.99973 and D13S317 was the system with highest Exclusion Power (0.6183). However, the highest real exclusion rate in this population was observed in the F13A01 system (0.7000), calculated over the number of F13A01 exclusions over the total paternity exclusions observed.