A SNaPshot assay for genotyping 44 individual identification single nucleotide polymorphisms

Area of Science:

• Forensic Science
• Genetics
• Molecular Biology

Background:

• Single nucleotide polymorphisms (SNPs) offer potential advantages over short tandem repeats (STRs) in forensic DNA analysis due to lower mutation rates and shorter amplicon lengths.
• Individual identification SNPs, characterized by high heterozygosity and low Fst values, function similarly to STRs in forensic applications.

Purpose of the Study:

• To develop and validate a multiplex typing method for simultaneously analyzing 44 selected individual identification SNPs.
• To assess the utility of this SNP multiplex assay in forensic routine work, including paternity testing and degraded sample analysis.

Main Methods:

• Development of a multiplex PCR reaction combined with fluorescent-labeled single base extension (SBE) technique.
• Design of PCR primers with amplicon lengths ranging from 69 to 125 bp.
• Investigation of population genetics data for 44 SNP loci in 79 unrelated Chinese individuals.

Main Results:

• Successful development of a 44-SNP multiplex typing assay.
• Validation experiments demonstrated the assay's sensitivity, species specificity, and effectiveness in paternity testing and degraded sample analysis.
• The 44-SNP multiplex assay provides valuable supplementary data when STR analysis is incomplete or fails.

Conclusions:

• The developed 44-SNP multiplex typing assay is suitable for forensic routine applications.
• This SNP-based method enhances forensic DNA profiling capabilities, particularly for challenging samples.