Mitochondrial DNA control region variation in a population sample from Thailand

Area of Science:

• Forensic Genetics
• Population Genetics
• Mitochondrial DNA Analysis

Background:

• Mitochondrial DNA (mtDNA) is crucial for forensic identification due to its high copy number and maternal inheritance.
• Reference databases are essential for interpreting mtDNA profiles in forensic investigations.
• Understanding population-specific mtDNA variation is key to accurate forensic analysis.

Purpose of the Study:

• To characterize the mitochondrial DNA control region sequences from a Thai population.
• To establish an mtDNA reference dataset for forensic applications in Thailand and Southeast Asia.
• To assess the genetic diversity and haplogroup distribution within the studied Thai population.

Main Methods:

• Sanger sequencing was employed to analyze the mitochondrial DNA control region from 213 hair samples.
• Haplotype and haplogroup diversity were calculated.
• Population genetic statistics (FST) were computed to compare with other Asian populations.

Main Results:

• A total of 170 distinct haplotypes were identified, with 146 being unique.
• High haplotype diversity (0.9960) and a low random match probability (0.87%) were observed.
• The most frequent haplogroups were B5a, F1a1a, and M; significant but low genetic differentiation was found with other Asian populations.
• Heteroplasmic positions were detected in 12.2% of the hair samples.

Conclusions:

• The analyzed Thai mtDNA control region data provides a valuable reference for forensic casework.
• The findings indicate close genetic relationships between the Thai population and other Southeast and East Asian populations.
• The high frequency of heteroplasmy in hair samples underscores its importance in forensic mtDNA interpretation.