US forensic Y-chromosome short tandem repeats database

Area of Science:

• Forensic Genetics
• Population Genetics
• Human Genetics

Background:

• Forensic Y-STR databases are crucial for identifying individuals and understanding population genetics.
• A comprehensive Y-STR database is needed to capture genetic diversity across various populations.

Purpose of the Study:

• To compile and analyze a large forensic Y-STR database from the US.
• To determine allele and haplotype frequencies for 16 Y-STR markers across six general populations.
• To assess population substructure and calculate forensic statistical parameters.

Main Methods:

• Compiled a database of 17,447 forensic Y-STR profiles, including 16 STR markers.
• Categorized samples into six populations (African American, Asian, Caucasian, Hispanic, Indian, Native American) and geographic subgroups.
• Calculated allele and haplotype frequencies, power of discrimination (PD), coancestry coefficient (F(st)), and coefficient of gene differentiation (G(st)).

Main Results:

• 93.7% of full 16-STR haplotypes were distinct, and 92.9% were population-specific.
• The most polymorphic marker was DYS385 due to its tandem duplication.
• Power of discrimination (PD) was 0.9998 for the total population dataset.
• G(st) and F(st) estimates were small for extended haplotypes, reducing further when Native American data was excluded.

Conclusions:

• The developed Y-STR database exhibits high discriminatory power and population specificity.
• Calculated forensic statistical parameters, including three measures of Y-STR profile frequency, provide conservative estimates.
• The binomial upper bound is recommended as the most conservative estimate for forensic applications.