Genetic Polymorphism and Forensic Parameters of Nine Short Tandem Repeat Loci in Ngoebe and Embera Amerindians of Panama

Nine STR loci (CSF1PO, TPOX, TH01, F13A01, FESFPS, VWA, D16S539, D7S820, and D13S317) were analyzed in unrelated Ngoebe and Embera Amerindians of Panama. The chi-square test demonstrated statistically significant differences (P < 0.001) in the allele frequencies for all markers except one (D16S539; P < 0.01). Both populations shared their alleles with the highest frequencies in seven loci. However, there were also noticeable differences at the TPOX locus, which showed its highest frequencies at alleles 11 (0.48) and 6 (0.54) for the Ngoebe and Embera, respectively. Interestingly, these alleles are present in one population and are absent in the other, suggesting that they could be distinctive for each population. These results demonstrate that, despite the fact that each population belongs to a different linguistic stock [Chibchan (Ngoebe) and Chocoan (Embera)], both retain strong similarities in their allele-frequency distributions. Three loci (TPOX, VWA, and F13A01) in the Ngoebe and two loci (TH01 and TPOX) in the Embera departed from Hardy-Weinberg equilibrium. The analysis of the STR markers demonstrates that, despite their low levels of genetic polymorphisms, most of them could be informative for forensic purposes, showing a combined power of discrimination of 0.9999 for both Amerindian populations. However, powers of exclusion in the Ngoebe were very low, particularly at the TH01 (0.04) and FESFPS (0.08) loci. The combined powers of exclusion were 0.9338 and 0.9890 for the Ngoebe and the Embera, respectively. Furthermore, the combined typical paternity index in the Ngoebe was considerably low (2.58), and in the Embera it was 40.44, which is also very low. The low genetic polymorphism levels suggest that the use of additional loci supplementing the battery of the nine loci is recommended for paternity and forensic tests in both populations, particularly for the Ngoebe.