Forensic evaluation of the DNATyper™ Y36 system: validation, mutation rates, and discriminative power

This study presents a validation and evaluation of the DNATyper™Y36 System. The system’s performance was rigorously assessed in terms of sensitivity, accuracy, species specificity, and resistance to common PCR inhibitors. To evaluate its ability to distinguish between related and unrelated males, we analysed 475 father–son pairs, 44 grandfather–grandson pairs from Inner Mongolia, and 557 randomly selected individuals from southwestern Han and Inner Mongolian populations in China. Locus-specific mutation rates were estimated for all 36 Y-STRs, and the discriminatory power of RM versus ML Y-STRs was compared. Mutation rates ranged from 0.0 to 14.74 × 10−3, with an average of 3.44 × 10−3. Increasing the number of loci – particularly RM loci – significantly enhances the system’s capacity to differentiate unrelated male lineages. θ-value analysis reveals that the incremental contribution of each additional locus to overall discrimination diminishes as the total number of loci increases, highlighting the need for a practical balance between locus count and resolution efficiency. The recommended configuration achieved 100% discrimination power and a haplotype diversity of 1.0 among 554 unrelated males. The DNATyper™Y36 System demonstrates high sensitivity, robustness, and reliability, confirming its suitability for forensic investigations and national DNA database development.