Genetic problems of DNA portrait as part of DNA phenotyping: A review

Forensic DNA databases are beneficial for investigating crimes and allow identifying a person using biological traces, provided that information about him/her is already available in the form of a short tandem repeat profile. The same is true for unidentified corpses. When such information is missing from the database, DNA phenotyping can be used. A person’s appearance can be reconstructed based on his DNA, which is already a finding application in forensic practice. Considerable progress is achieved when the hair and eye color, skin pigmentation, and some other features are established. However, the main interest is in the human face. However, developments in this area are limited. The main issue is that multiple genes are responsible for facial features, including a pleiotropic effect. The emergence of such a method such as genome-wide association study made it possible to analyze many gene loci at once for the presence of single-nucleotide substitutions associated with certain genes involved in the formation of a person’s face. However, sequencing of two genomes (or exomes) of each person inherited from the father and mother with phased haplotype assembly of their sequences can be more informative. With this approach, the accurate selection of objects in the form of a large number of twins and their closest relatives is critical, because twins may carry the same nucleotide substitutions, which largely determine their external similarity. Another cohort should be families in which children are very similar to their parents. In this case, it is crucial to conduct triosequencing with phased assembly of their diploid genomes (exomes). Genetic information obtained in this way, which is processed using machine learning and artificial intelligence, allow us to “reach” the necessary genes, increasing the reliability of such DNA portraits.