Гендерные локусы в ДНК-криминалистике и женском спорте

Abstract

In forensic medicine, it is necessary to establish the sexual identity of the owner of the analyzed biological material. To do this, it is necessary to use PCR to detect specific DNA sequences that are characteristic only of the Y chromosome. For these purposes, a number of loci are used, located on both the Y and X chromosomes but carrying certain differences in the nucleotide sequences (alpha satellites DYZ and DXZ; amelogenin loci AMELY and AMELX; STS steroid sulfatase genes; the genes of the neuroligin NLG4Y and NLG4X, etc.), and those located only on the Y-chromosome (sex-determining region SRY; gene of the specific testicular protein TSPY, etc.). At the same time, forensic experts often deal with damaged or old samples in which the DNA has been destroyed and extended fragments in it may simply not be, as a result of which false negative results will be formed. Thus, in DNA forensics, when detecting gender loci, the sizes of amplicons should tend to the minimum possible. Therefore, in this review article, a certain emphasis was placed on the size of amplicons, and as practice shows, for most loci, their minimization is in demand. Moreover, such a PCR analysis in a number of cases (in XX-men, XY-women, in persons with other sex chromosome abnormalities, in people who deliberately changed their gender identity) it can lead to a false definition of the phenotypic sex due to the genetic characteristics of such individuals. As a result, the ongoing investigation of a crime, focused on the search for a representative of a particular gender, can go down the wrong path. A cardinal solution to this problem in DNA criminology can be a universal DNA registration of the entire population, which will allow for the biological traces with high accuracy to establish a specific person to whom these traces belong and his real sex will no longer be important and it will not be relevant to determine it with the help of PCR. In addition to forensic medicine, the problem of establishing gender also exists in women's sports. For a whole decade, the PCR method and some of the loci listed above were used for this purpose, but since 2011 PCR has been abandoned and instead the level of the male hormone testosterone has became determined. However, with the gender of female athletes, there are much more ethical issues than genetic ones.