Forensic science and DNA mutations

DNA analysis and individual DNA-based database entries that allow identification of any criminal which DNA samples were once submitted into the database, started to form in early 1980-s. Since that time, DNA testing evolved greatly and became powerful tool for investigation and forensic identification in the needs of jusitice. One of the important aspects of information about the individual that forensic scientist could obtain from analysis of DNA sample is knowledge concerning mutations that are specific for the given individual.

It is known that variable regions of the human genome comprise wery small part of the total genome – about 0,1% of total cellular DNA. Mutations that occur in regions of DNA that are constant in most humans, create difference in genomic pattern that could allow identification of that mutation carrier quite easily. Every mutation is more or less rare in the population, and relative frequency of occurence of most widespread mutations is known and usually these frequencies are rather low.

Atypical mutations have even lower frequencies of occurence and may even be unique for that carrier, and thus detection of such mutation will ensure identification of the carrier. Additional way that study of DNA muations can contribute to forensic identification is knowledge of the ways how genomic changes manifest in the phenotype.

This could allow preliminary description of a criminal that is a carrier of certain mutation, to be drawn up based on knowledge concerning ways how given mutation impacts phenotype of the criminal, and thus facilitate detection of that criminal by citizen, which surely would help capture that criminal. Even if mutations doesn’t affect genes that are responsible for phenotypical features and thus impact of mutations is not onservable enough, mutations could alter patterns of genetic fingerprints by changing, creating or destroying restriction sites in DNA sequence.