Forensic parameters and mutation analysis of 23 short tandem repeat (PowerPlex® Fusion System) loci in Fujian Han...

Kinship testing based on genetic markers has valuable practical applications. Short tandem repeat polymorphisms (STRPs) can have large number of alleles, and become the dominant marker for kinship identification. However, the high mutation rates affect the identification accuracy. Thus, accurate investigation of the mutation rate of STR loci in different populations is crucial for the reliability of phylogenetic relationships. In present study, forensic parameters and mutation rates (include 95% CI) of 23 short tandem repeats (STR) loci (D3S1358, D1S1656, D2S441, D10S1248, D13S317, D16S539, D18S51, D2S1338, CSF1PO, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433, FGA, D22S1045, PentaE, PentaD and DYS391) were investigated through PowerPlex® Fusion System in Fujian Han population. The high level of CDP (0.999999999999999999999999992) and CPE (0.999999993) indicated the panel was high efficiency in forensic DNA identification and paternity testing. In mutation analysis, 43 mutation cases were found through 54,124 parent-child meiotic transfers. The observed mutation rates ranged from 0 (D3S1358, D1S1656, D13S317, TH01, D19S433 and D22S1045) to 0.0025 (PentaE and FGA). The overall mutation rate across all loci was 0.0008 and the average mutation rate for the 23 loci was estimated to be 0.00078 per meiosis. The vast majority of mutations were single-step (88.4%) mutation and also include double-step (9.3%) and triple-step (2.3%) mutations. Paternal mutation rate was more common than maternal mutation rate with a ratio of 7.2:1. In addition, mutation rates indicated positive correlation (r = 0.633, p = 0.009) with the expected heterozygosity (H_e).