Prediction of Physical Characteristics, such as Eye, Hair, and Skin Color, Based Solely on DNA

Over the last 15 years, appearance prediction using DNA, also known as forensic DNA phenotyping (FDP), has emerged as an invaluable approach to glean intelligence information from a biological sample and/or human remains. This chapter shall explore how the field arose, from fundamental complex genetics exploring the variation that exists within eye, hair, and skin color pigmentation, toward the assessment of useful predictors from genes impacting its development, in addition to descriptions and comparisons of some of the fields of top pigmentation prediction systems. An in-depth look at pigmentation gene discovery will be described with a look at the different cell types that exist and how they display the variation that can be seen within the iris, hair follicle, and epidermis. The development of prediction systems and the methodologies of categorical pigment prediction are discussed with a focus on two freely available online predictor systems: HIrisPlex and Snipper Suite. Lastly, a look toward the future for pigmentation prediction, and how complementary phenotypes such as hair structure and facial morphology compare with regards to their current genetic knowledge, with a brief discussion on their future capacity to predict from DNA.