Spanish population data on the loci D13S317, D7S820, and D16S539 generated using silver staining (SilverSTR III...

A set of 212 samples from unrelated Spanish Caucasians living in Andalucia (southern Spain) were analyzed with a new commercially-available kit for multiplex amplification of 3 STR loci (D13S137, D7S820, and D16S539), manual denaturing polyacrylamide gel electrophoresis and silver staining. These three loci are of special interest for the forensic community since they are a part of the 13 CODIS-core STR loci. The results show that the loci D13S317 and D16S539 meet Hardy-Weinberg expectations (HWE), but the locus D7S820 did not meet HWE (p = 0.003). However, there was no detectable departures from independence (i.e., linkage disequilibrium) between any pair-wise combination of loci. The D7S820 data were further investigated. The excess homozygosity was due to an excess of D7S820 10, 10 homozygotes. To determine if the allele frequency data are meaningful and can be applied to forensic identity cases, the Spanish D7S820 allele frequency data were compared with four other Caucasian sample populations. The D7S820 allele frequencies were statistically similar; thus, the results support that the allele frequency data can be used reliably for estimating DNA profile frequencies.