We observed a significant deviation in HWE for both LB (D19S433, D21S11, D22S1045, and Penta E) and RSB (D19S433, D22S1045, D1S1656, D2S441, and Penta E) variation in aSTRs after Bonferroni correction, as well as in three iiSNPs (rs6444724, rs6955448, and rs1493232). These results may be caused by sampling errors, especially when it comes from a cosmopolitan population such as Monterrey City, the second-most-important metropolis in Mexico. Although a larger population sample size could exhibit more allele diversity, producing more accurate estimates, we were able to observe as far as 367 different aSTR alleles, which is similar or superior to previous studies with the DPS-A of the ForenSeq™ DNA Signature Prep [3–5].
This study follows the ISFG recommendation regarding the generation of STR allele population databases [13], which are required for biostatistical interpretation in kinship analysis and criminal cases where ForenSeqTM DNA Signature Prep kit is used. For instance, in a recent complex paternity case reported in Mexico, the suitability of a forensic genomic platform was invoked [17]. However, the largest social impact of genomic platforms is expected in criminal investigation, given the 40,180 missing persons and 37,000 unidentified bodies in Mexico [18]. Consequently, the genomic population database reported herein will be helpful for this task in Mexico, but also Latin American populations using the ForenSeqTM DNA Signature Prep kit without a proper population database.
To our best knowledge, this is the first study where forensic MPS-based data was reported in a Mexican population and is the second report from Latin America. Although the previous Latin American study in Peruvian population reported forensic parameters of aSTRs and iiSNPs with the same forensic MPS platform, they did not report X-STR and Y-STRs population data [6]. Thus, for these STRs the reported Mexican population database is the first one available in Latin America for interpretation purposes.
The number of different alleles found here (528 different STR alleles) was higher than those reported in Spanish [3], French [4], Asian [5], and Peruvian [6] populations. Also, our RSB results improve importantly the combined PD and CE compared with those previously obtained in Monterrey City but based on 23 aSTRs genotyped by CE [19]. As expected, our sequencing results for the 24 Y-STRs also improve the genetic informativity from Monterrey City regarding that previously reported with 23 Y-STRs based on CE, where a discriminatory capacity of 93.75 % was described [20]. Although our sample size is smaller, with sequencing results a higher discriminatory capacity is expected due to RSB variation.