Forensic DNA phenotyping: Inferring phenotypic traits from crime scene DNA.

Introduction: Forensic DNA Phenotyping (FDP) has provided better understanding of various phenotypic features (e.g., height, skin colour, eye colour, structure and shape of scalp hair, baldness, facial features etc.) and associated genetic variations. The current study was designed to investigate the genetic variants and their potential contribution towards accurate phenotype prediction systems. Short Tandem Repeat (STR) based DNA typing method can be uninformative or with little potential to solve a crime in absence of suspect DNA profile in the database. Forensic DNA Phenotyping (FDP), prediction of externally visible characteristics (EVCs) from the crime scene DNA would certainly provide a new dimension to personal identification. The aim of this review paper is to highlight the significance and future prospects of FDP.

Results: A comprehensive literature review was conducted using PubMed and similar e-databases with keywords from two main components-phenotype and the associated genetic variants. To ensure a thorough literature review, searches were extended using the snowballing technique from reference lists. Key data extracted were type of study, sample characteristics (sample size, age, geographical location and ancestry), details of SNPs studied and prediction accuracies.

Conclusion: Phenotyping tools based on genotyping and statistical analysis for the prediction of human pigmentation are propitious in solving cold cases. This indicates the inevitability of future studies for the identification of new genetic markers for accurate prediction of phenotype or EVCs via genome-wide association study (GWAS) in diverse global populations.