Paternal and maternal mutations in X-STRs: A GHEP-ISFG collaborative study

Area of Science:

• Forensic Genetics
• Population Genetics
• Molecular Biology

Background:

• The Global FSI (GHEP-ISFG) organized a collaborative study to determine mutation rates for specific genetic markers.
• Accurate mutation rate estimation is crucial for forensic DNA analysis and kinship testing.

Purpose of the Study:

• To estimate maternal and paternal mutation rates for markers in the Investigator Argus X-12 QS kit.
• To analyze population genetic diversity and stratification across several South American and European countries.
• To investigate the influence of parental age on mutation transmission.

Main Methods:

• Data from 1,612 father/mother/daughter trios across 16 laboratories were analyzed.
• Population genetic analyses utilized data from 1,327 unrelated daughters (2,654 haplotypes) from Argentina, Brazil, Ecuador, Portugal, and Spain.
• Mutation types and parental age effects were assessed.

Main Results:

• Overall locus-specific mutation rates ranged from 7.5E-04 to 1.1E-02.
• Paternal mutation rates were 5.2 times higher than maternal rates.
• Older fathers showed a higher propensity to transmit mutated alleles, unlike mothers.

Conclusions:

• The study provides crucial mutation rate data for the Investigator Argus X-12 QS kit markers.
• High genetic diversity and novel alleles were observed, necessitating large databases for frequency estimation.
• Paternal age is a significant factor influencing mutation rates, impacting forensic and kinship analyses.