Evaluation of the InnoTyper® 21 genotyping kit in multi-ethnic populations

Evaluation of the usefulness of insertion-null markers in critical skeletal remains

Forensic DNA analysis in compromised skeletal remains may pose challenges due to DNA degradation, often resulting in partial or negative autosomal STRs profiles. To address this issue, alternative approaches such as mitochondrial DNA or SNPs typing may be employed; however, they are labour-intensive and costly. Insertion-null alleles (INNULs), short interspersed nuclear elements, have been suggested as a valuable tool for human identification in challenging samples due to their small amplicon size. A commercial kit including 20 INNULs markers along with amelogenin (InnoTyper® 21) has been developed. This study assesses its utility using degraded skeletal remains, comparing the results obtained (the number of detected alleles, RFU values, PHR, and the number of reportable markers) to those obtained using GlobalFiler™. Subsequently, the random match probability of the two profiles for each sample was determined using Familias version 3 to evaluate the power of discrimination of the results obtained from each kit. In every sample, InnoTyper® 21 yielded more alleles, higher RFU values, and a greater number of reportable loci. However, in most cases, both profiles were similarly informative. In conclusion, InnoTyper® 21 serves as a valuable complement to the analysis of challenging samples in cases where a poor or negative profile was obtained.

Population data for 20 insertion-null allele markers in the Li ethnic minority from Hainan Province

Insertion/null polymorphisms (INNULs) can be used as an alternative marker of STRs to detect the highly degraded samples in forensic cases. In this study, we evaluated the genetic data of 20 INNUL markers in the Innotyper® 21 Human DNA Analysis Kit (InnoGenomics) for Hainan Li population, including allele frequencies and forensic parameters. No significant deviation from Hardy-Weinberg equilibrium and linkage disequilibrium was found in all loci after Bonferroni correction. The combined power of discrimination (CPD) was 0.99999891, the combined power of exclusion for duo paternity testing (CPEduo) was 0.75274389, and the combined power of exclusion for trio paternity testing (CPEtrio) was 0.94766143. These data would be useful for the application of the kit in practice and the research of the kit used in molecular anthropology studies.

Evaluation of the InnoTyper21® system for the applications into trace and degraded DNA in the Korean population

The InnoTyper 21® Human Identification kit consists of amelogenin and 20 bi-allelic Alus, retrotransposon markers existing abundantly in human genome. The InnoTyper 21® kit produces shorter amplicons (60-125 bp) than conventional short tandem repeat (STR) genotyping kit, then it is effective on the analysis of challengeable forensic samples including insufficient or highly degraded DNAs. Also, as the genotyping with InnoTyper21® kit is compatible with PCR and capillary electrophoresis, it is easy to incorporate into the workflow in forensic laboratories. In the internal validation of InnoTyper21® kit on sensitivity, degradation, and mixture studies for the evaluation in this study, we acquired full profiles on analyzing small concentration DNA (as low as 25 pg) and highly degraded DNA (up to 105 degradation index value). Through the Korean population study, forensic statistical parameters were investigated and a specific variant of T insertion in NBC51 was confirmed in six samples. Comparison of Korean population with five populations or 1000 Genomes Project data show Korean specific substructure. It is expected that the InnoTyper 21® kit will be used into the actual forensic cases, utilizing the population study investigated through this research.

Population genetic data of 20 insertion-null allele markers in the Andalusian population

Genetic data from 21 autosomal insertion-null (INNULs) markers found in the InnoTyper® 21 Human DNA Analysis (InnoGenomics®) was evaluated in 190 unrelated individuals from Andalusia. Allele frequencies and forensic parameters were estimated for the 20 INNULs. All loci were in Hardy-Weinberg equilibrium in the study population after Bonferroni correction and showed no signs of linkage between them. The combined power of discrimination and the power of exclusion for the 20 INNULs were 1-7.42352 × 10^-9 and 93.60946%, respectively. These data might be useful for the research of population genetics and for individual identification and paternity testing in forensic science.