Evaluation of mitochondrial DNA coding region assays for increased discrimination in forensic analysis

Area of Science:

• Forensic Genetics
• Molecular Biology
• Population Genetics

Background:

• Mitochondrial DNA (mtDNA) analysis is crucial in forensics, especially with limited DNA samples.
• The mtDNA control region offers low discrimination due to uniparental inheritance and lack of recombination.
• Coding region variations are explored to enhance mtDNA's discriminatory power in forensic investigations.

Purpose of the Study:

• To evaluate the discriminatory capacity of various mitochondrial DNA coding region typing assays.
• To assess the utility of these assays for forensic casework, particularly with identical control region profiles.
• To incorporate local geographic data by analyzing Swedish mtDNA sequences.

Main Methods:

• Analysis of 495 complete Caucasian mtDNA sequences.
• Sequencing and analysis of complete mtDNA from 20 individuals of Swedish origin.
• Evaluation of several established mitochondrial DNA coding region typing assays for their discrimination power.

Main Results:

• Coding region assays effectively resolve mtDNA sequences with identical HVI/HVII regions.
• The most effective coding region assay discriminated 46% of resolvable sequences.
• Other evaluated coding region assays showed discrimination rates between 20-30%.

Conclusions:

• Mitochondrial DNA coding region typing assays significantly enhance discrimination beyond control region analysis.
• These assays are valuable tools for forensic identification when standard mtDNA methods yield ambiguous results.
• The findings support the broader application of coding region analysis in forensic genetics.