HIrisPlex-S

HIrisPlex-S predicts eye, hair, and skin color from genetic variant data for forensic DNA phenotyping using massively parallel sequencing (MPS) genotypes.

Key Features:

• Genetic basis: HIrisPlex-S uses 41 DNA variants associated with externally visible characteristics including eye, hair, and skin color.
• Sequencing platforms: Compatible with Ion Torrent (Ion AmpliSeq) and MiSeq MPS platforms, with reported complete profiles from ~100 pg input DNA for the Ion AmpliSeq assay and ~250 pg input DNA for the MiSeq in-house assay.
• Forensic validation: Developmental validation of both MPS assays includes testing on simulated forensic samples (saliva, hair bulb, blood, semen, low-quantity touch DNA) and artificially damaged DNA, with concordance testing and cross-species sample analysis.
• Bioinformatics pipeline: An integrated bioinformatics analysis pipeline processes MPS data and generates files for upload to the online HIrisPlex webtool (https://hirisplex.erasmusmc.nl), and the webtool accepts VCF input data.
• Mixture analysis tool: A 2-person mixture separation tool assesses genotype reliability and identifies the most fitting mixture scenario for minor and major contributors.

Scientific Applications:

• Forensic DNA phenotyping: Prediction of eye, hair, and skin color from genotype data to support forensic casework.
• Research and extension: Use in research into externally visible characteristics with potential expansion to additional SNPs and future incorporation of biogeographic ancestry inference pending appropriate statistical frameworks.

Methodology:

An integrated bioinformatics pipeline processes MPS data to produce files (including VCF) for upload to the HIrisPlex webtool, and a 2-person mixture separation tool evaluates genotype reliability and proposes mixture scenarios.