Forensic DNA phenotyping in Southeast Asian populations: a scoping review

Background Forensic DNA phenotyping (FDP) provides vital investigative leads by predicting externally visible characteristics (EVCs). However, a significant “genomic gap” exists as most FDP models are calibrated on European or East Asian datasets, limiting their reliability in the genetically diverse Southeast Asian (SEA) region. Main body This scoping review, following PRISMA-ScR guidelines, systematically mapped genetic markers for pigmentation and craniofacial morphology across SEA populations. We synthesized data from 25 eligible studies (2020–2025) including genome-wide association studies and whole-genome sequencing. Results reveal pronounced intra-regional genetic heterogeneity, particularly in SLC24A5 and OCA2 loci, with allele frequencies (e.g., rs1426654) showing sharp stratification between Western and Eastern Indonesian groups. Furthermore, novel associations for skin texture, ADGRL2 for cheek color and LINGO2 for pore size, were identified in Thai and Indonesian cohorts yet remain absent from standard forensic panels. Evaluation of current FDP tools (e.g., ForenSeq, HIrisPlex-S) demonstrates reduced resolution for differentiating closely related SEA sub-populations. Conclusion These findings highlight the limitations of uniform ‘Asian’ reference panels and highlight the risk of predictive bias. We conclude that region-specific genomic databases are essential to improve the accuracy and equity of DNA-based facial prediction in SEA.