Analysis of tri-allelic SNPs for forensic purpose in Chinese Han population

Abstract

Single nucleotide polymorphisms (SNPs) have been proved to be effective forensic marker for supplementary paternity testing and forensic identification due to their low mutation rate and depending on small amplicon size. However, at least a set of 50–60 binary SNP loci can reach discrimination power of 13 STR loci that were routinely used in forensic practice. Meanwhile, binary SNP loci were ineffective to detect mixed samples, which may result in incorrect genotyping. In this study, we aimed to find out the potential forensic markers, tri-allelic SNP loci in Chinese Han population. Pyrosequencing (PSQ) with pooling samples was used to analyze candidate SNP loci and estimate allele frequencies of them. To confirm the existence of three alleles, individual samples were sequenced with PSQ method. Our results revealed that there were 10 tri-allelic SNP loci resided on 10 autosomal chromosomes in Chinese Han population. These data demonstrated that PSQ was an effective method to detect tri-allelic SNPs and estimate allele frequencies of them.