Development of a SNP-based panel for human identification for Indian populations

Area of Science:

• Forensic genetics
• Population genetics
• Molecular biology

Background:

• Short tandem repeat (STR) panels used in forensic human identification (HID) struggle with degraded DNA samples.
• Single nucleotide polymorphisms (SNPs) and insertion-deletions (indels) are more robust for degraded DNA in HID.
• Limited data exists on biallelic markers for HID in genetically diverse Indian populations.

Purpose of the Study:

• To design and validate a SNP-based panel for human identification specifically tailored for Indian populations.
• To address the limitations of STR markers in challenging forensic samples within the Indian context.

Main Methods:

• A two-step approach was used to design a 70 SNP panel.
• Candidate SNPs were screened from public databases and genotyped in 462 individuals from various Indian populations.
• Statistical analyses, including heterozygosity and FST, were performed to select optimal SNPs.

Main Results:

• Out of 592,652 initial SNPs, 275 were shortlisted, and 206 met desired allelic distribution criteria.
• A final panel of 70 SNPs was constructed, demonstrating high discriminatory power.
• The developed panel achieved an average match probability of 10e-29, significantly outperforming existing STR and SNP panels.

Conclusions:

• The 70 SNP panel is highly efficient and robust for human identification in Indian populations.
• This SNP panel overcomes limitations of STR markers with degraded DNA samples.
• The panel offers superior performance for forensic applications in India's diverse genetic landscape.