Genetic predictions of eye and hair colour in the Danish population

TY - JOUR

T1 - Genetic predictions of eye and hair colour in the Danish population

AU - Cabrejas-Olalla, Amaia

AU - Jørgensen, Frank G.

AU - Cheng, Jade Y.

AU - Kjærgaard, Peter C.

AU - Schierup, Mikkel H.

AU - Mailund, Thomas

AU - Athanasiadis, Georgios

N1 - Publisher Copyright: © 2025 Elsevier B.V.

PY - 2025/6

Y1 - 2025/6

N2 - Genetic predictions of eye and hair colour are prominent examples of forensic DNA phenotyping that can help resolve criminal cases. The advent of high-throughput genotyping technologies in forensic genetics opens up the possibility of applying polygenic risk scores in forensic settings. In this work, we compare the performance of HIrisPlex with PRSice-2 in predicting eye and hair colour to gain insights into the relative benefits of new approaches. Predictions were carried out on 584 Danish high school students for which genetic and self-reported phenotype data were available. Prediction of brown eye colour was very accurate (AUC = 0.98), followed by blue eye colour (AUC = 0.82), while it failed for intermediate eye colour (AUC = 0.57). As for hair colour, red and black were overall better predicted than blond and brown, and PRSice-2 performed better in all but the black hair colour. Despite the limitations of the study, HIrisPlex exhibited its usual high performance in the prediction of brown and blue eye colour, as well as red and black hair colour. However, PRSice-2 offered overall improvements in hair colour prediction over HIrisPlex suggesting that there is room for improvement in forensic DNA phenotyping by using polygenic risk scores.

AB - Genetic predictions of eye and hair colour are prominent examples of forensic DNA phenotyping that can help resolve criminal cases. The advent of high-throughput genotyping technologies in forensic genetics opens up the possibility of applying polygenic risk scores in forensic settings. In this work, we compare the performance of HIrisPlex with PRSice-2 in predicting eye and hair colour to gain insights into the relative benefits of new approaches. Predictions were carried out on 584 Danish high school students for which genetic and self-reported phenotype data were available. Prediction of brown eye colour was very accurate (AUC = 0.98), followed by blue eye colour (AUC = 0.82), while it failed for intermediate eye colour (AUC = 0.57). As for hair colour, red and black were overall better predicted than blond and brown, and PRSice-2 performed better in all but the black hair colour. Despite the limitations of the study, HIrisPlex exhibited its usual high performance in the prediction of brown and blue eye colour, as well as red and black hair colour. However, PRSice-2 offered overall improvements in hair colour prediction over HIrisPlex suggesting that there is room for improvement in forensic DNA phenotyping by using polygenic risk scores.

KW - Danish population

KW - Eye colour

KW - Hair colour

KW - HIrisPlex

KW - Polygenic risk scores

KW - PRSice-2

UR - http://www.scopus.com/inward/record.url?scp=85219733855&partnerID=8YFLogxK

U2 - 10.1016/j.fsigen.2025.103267

DO - 10.1016/j.fsigen.2025.103267

M3 - Journal article

C2 - 40056823

AN - SCOPUS:85219733855

SN - 1872-4973

VL - 78

JO - Forensic Science International: Genetics

JF - Forensic Science International: Genetics

M1 - 103267

ER -