Evaluation of the use of molecular markers for the prediction of human facial features for forensic purposes: a systematic review.

The prediction of phenotypic traits from DNA, known as forensic DNA phenotyping, or externally visible characteristics, represents a disruptive evolution in contemporary forensic genetics. Although various studies have identified molecular markers associated with facial features, the predictive accuracy of these markers varies significantly between populations due to their genetic background and representative sampling of relevant populations. This systematic review aimed to analyze and synthesize existing studies on forensic DNA phenotyping, evaluate the accuracy of different types of markers, and compare their effectiveness in predicting human facial features. The publication screening was based on the 2020 PRISMA and the search was conducted in three different databases: Scopus, PubMed, and Web of Science, published through May 23, 2025, yielding a total of 301 initial records. After article screening, 28 studies were selected for analysis which were published between 2013 and 2025 and were written in English. A total of thirteen facial feature categories were identified among which facial morphology, presence or absence of freckles, and male-pattern baldness stand out for being associated with a greater number of SNPs. The systematic literature review highlights significant progress in genetic appearance prediction, validating both established assays and in-house panels. While common pigmentary traits achieve high predictive accuracies (> 89-90%), predicting complex facial morphology (e.g., overall facial configuration and 3D landmarks) remains a major challenge due to its highly polygenic architecture. Furthermore, the transferability of these predictive models to genetically heterogeneous and admixed populations, such as Latin American cohorts, requires population-specific optimization and future standardized frameworks.