Stages of the Great Journey: From Primary DNA Identification of an Individual to Future DNA Registration of the Entire Population

Tremendous progress has been made in the four decades since the introduction of DNA profiling in forensic science and forensic medicine, the culmination of which is to be the DNA registration of the entire population. During this period, DNA markers have evolved, DNA analysis technologies have improved, including the development of DNA sequencing, which has had a profound impact on forensic medicine. Since the mid-1990s, STR loci have been used for DNA identification, and they remain the “gold standard” today. During the 30-year dominance of STR loci, there have been repeated attempts to introduce other markers into DNA forensics, particularly single-nucleotide polymorphisms (SNPs), which are less susceptible to mutation and are the most common type of DNA polymorphism. Initially, SNPs were thought to be exclusively biallelic, and therefore inferior to multiallelic STR loci in discriminatory power. However, at the beginning of the new century, it was discovered that tri- and tetra-allelic SNPs exist, yielding higher number of combinations. Even greater interest in them arose due to their role in determining human phenotypic traits, leading to the development of DNA phenotyping. Later, it was suggested to use SNPs inherited in a linked manner as part of microhaplotypes. The latter are more correctly considered microdiplotypes, representing two microhaplotypes from identical regions of paired chromosomes. Microdiplotypes provide low probability of random matching (up to 10–100), surpassing STR loci in this parameter, while simultaneously having a lot of other advantages, making them candidates as DNA markers for DNA registration of entire population.