Sequenced-based Rwanda population provides insights into demographic history.

Rwanda is known as the heart of Africa, reflecting the history of the world. Colonization and genocide have led to Rwanda's existing genetic structure. Herein, we used massively parallel sequencing to analyze 296 loci in 185 Rwandans and constructed a database for Rwandan forensic data for the first time. We found the following results: First, forensic parameters demonstrated that all loci were highly informative and could be used for forensic identification and paternity tests in Rwandans. Second, we found that the differences in genetic background between Rwandans and other African populations were similar but slight, as indicated by the massively parallel sequencing panel. Rwandans belonged to the African population and were inseparable from populations from neighboring countries. Also, Rwandans were closer to the European and American populations because of colonization, war, and other reasons. There was no scientific basis for racial classification established by colonization. Further research still needs to be carried out on more loci and larger Rwandan samples.

A novel forensic panel of 186-plex SNPs and 123-plex STR loci based on massively parallel sequencing.

The MiSeq® FGX Forensic system and the HID-Ion AmpliSeq Panel were previously developed for massively parallel sequencing (MPS) for forensic casework. Among the three major sequencing platforms, BGISEQ-500TM, which is based on multiple PCRs, is still lacking in forensics. Here, a novel forensic panel was constructed to detect 186 single-nucleotide polymorphisms (SNPs) and 123 short tandem repeats (STRs) with MPS technology on the BGISEQ-500™ platform. First, the library preparation, sequencing process, and data analysis were performed, focusing on the average depth of coverage and heterozygote balance. We calculated the allelic frequencies and forensic parameters of STR and SNP loci in 73 unrelated Chinese Han individuals. In addition, performance was evaluated with accuracy, uniformity, sensitivity, PCR inhibitor, repeatability and reproducibility, mixtures, degraded samples, case-type samples, and pedigree analyses. The results showed that 100% accurate and concordant genotypes can be obtained, and the loci with an abundance in the interquartile range accounted for 92.90% of the total, suggesting reliable uniformity in this panel. We obtained a locus detection rate that was higher than 98.78% from 78 pg of input DNA, and the optimal amount was 1.25-10 ng. The maximum concentrations of hematin and humic acid were 200 and 100 µM, respectively (the ratios of detected loci were 96.52% and 92.41%), in this panel. As a mixture, compared with those of SNPs, minor-contributor alleles of STRs could be detected at higher levels. For the degraded sample, the ratio of detected loci was 98.41%, and most profiles from case-type samples were not significantly different in abundance in our studies. As a whole, this panel showed high-performance, reliable, robust, repeatable, and reproducible results, which are sufficient for paternity testing, individual identification, and use for potentially degraded samples in forensic science.