English and Irish population comparison using STR markers: Insights into genetic disparities and historical influences

Abstract

Short tandem repeat (STR) markers are commonly used in forensic investigations and kinship testing due to their cost-effectiveness and high discriminatory power. In the United Kingdom, STR allele frequency databases are available for different population groups, including the White group, which includes individuals of both English and Irish ethnicity. However, considering differences in historical migrations and influences between England and Ireland, distinct genetic differences might exist between these populations. This study aimed to generate allele frequency data for English and Irish populations using the VeriFiler Express PCR Amplification Kit, which contains loci utilised in national databases. Buccal swabs were collected from 577 English and 500 Irish volunteers with self-proclaimed English and Irish ethnicity respectively. DNA profiling and statistical analyses were performed to assess allele frequencies and forensic parameters, and to perform population comparisons. The results showed minimal genetic differentiation (F_st = 0.0013) between the English and Irish populations. Comparison with other European populations revealed close genetic relationships between the English population and Scandinavian countries, while the Irish population displayed closer genetic links to Western European countries. These findings support historical influences such as Viking migrations and highlight the need for further research using additional markers to explore the genetic makeup and history of the English and Irish populations. Although a single allele frequency database may be suitable due to the observed genetic similarity, the establishment of separate databases should be considered to ensure maximum population representation.