[Calculation of the avuncular index]

Area of Science:

• Forensic genetics
• Population genetics
• Statistical genetics

Context:

• Determining familial relationships is crucial in forensic investigations.
• Traditional methods for establishing uncle-niece relationships can be challenging.
• Autosomal Short Tandem Repeat (STR) loci provide valuable genetic markers.

Purpose:

• To introduce and validate a novel method for calculating the avuncular index (AI).
• To assess the reliability of the AI calculation using different genetic coefficients and laws.
• To evaluate the influence of including the child's mother on AI results.

Summary:

• The study employed identity by descent coefficient, coancestry coefficient, and AI law to identify uncle-niece relationships.
• Autosomal STR loci data were utilized to resolve disputed familial connections.
• AI calculations yielded consistent results across all three applied methods.

Impact:

• The findings confirm the reliability of the avuncular index (AI) across various genetic methodologies.
• The study highlights that AI values increase when the child's mother is part of the analysis.
• This research offers a robust tool for forensic genetics, enhancing the accuracy of kinship analysis.