A Novel Panel of 36 Insertion/Deletion (InDel) Markers for Human Identification

Background: In recent years, the insertion/deletion (InDel) polymorphism has become a preferred genetic marker in forensic genetics due to its low mutation rates and small amplicon sizes. In this study, a 36-InDelplex identification panel, consisting of autosomal 34 InDel loci, 1 Y InDel locus, and amelogenin, was developed and gene frequencies in the Turkish population were determined. Methods and Results: The loci of the InDel panel with global minimum allele frequencies (MAF) ≥ 0.4 were selected from the 1000 Genomes Project Phase 3 data. The amplicon sizes of the loci were designed to be smaller than 250 bp. In the validation study of the created panel, analysis threshold, dynamic range, sensitivity, stochastic threshold, inhibitor tolerance, and reproducibility parameters were studied in accordance with the Scientific Working Group on DNA Analysis Methods (SWGDAM) guideline. The sensitivity studies indicated that complete and reliable InDel profiles could be obtained with 0.25 ng of DNA. The 36-InDelplex panel was evaluated using the 250 samples from individuals of Turkey. The mean observed heterozygosity ratio (Ho) of all loci was 0.48. Combined discrimination power (CPD) is 0.999999999999988 and combined exclusion probability (CPE) is 0.9987. The population comparison also made using Turkish and each of the five major populations 1000 Genomes Phase 3 populations’ data for each of the five major populations (i.e., African, European, East Asian, South Asian, and American). Conclusions: The results showed that the 36-InDelplex panel is a reliable, sensitive and accurate system, which is suitable for human identification and population genetics purposes.