Gene frequency of X chromosome indel loci in Turkey

In recent years, InDel (insersion-deletion) is a polymorphism that occurs as a result of the addition or subtraction of nucleotides in the genome from the genetic variants that have gained importance. The InDels make up about 16% of all human DNA polymorphisms. These locus are located on both somatic chromosomes and sex chromosomes. Power of discrimination and heterozygosity rates are high. It is preferred especially for biogeographical ancestry research and identification studies, as it provides a good distinction between populations. InDel locus located on chromosome X can be used in paternity and maternity cases, kinship relationships, DNA profiling of disaster victims, identification of biological evidence collected from crime scene. Since PCR products are small, it is possible to make a successful typing in degraded samples and trace quantities. In order to be able to use InDels in the solution of cases in routine criminal laboratories, it is necessary to know the frequency of the cases in the relevant population. 22 InDel locus of X chromosome have been identified gene frequencies in Turkey. For this purpose at the first stage, DNA was isolated and the amount was determined of the buccal swab samples taken from 250 volunteers (126 males, 124 females) to reflect all regions of Turkey. In the second stage, after optimization and validation studies carried out in parallel with this thesis study, "Multiplex panel development of InDel locus located on X chromosome", the panel of InDel locus was amplification by PCR. In the third stage, electrophoresis and analysis of PCR products were performed. At the latest stage; gene frequencies were determined in the Genemapper® v.4 genetic analyzer. The HW balance and the differentiation between populations (FST) of each locus were calculated in the Arlequin v.3.5.1.2 program. With the PowerStats Microsoft® Excel file, the forensic statistical parameters were calculated. And the phylogenetic tree was drawn in the Mega X v.10.0.5 program according to the FST result. The average heterozygosity of 22 InDel locus was 0.4690. When 22 locus were studied together, the discrimination power was 99%. 22-X InDel panel working alone; it was determined that the necessary power of exclusion and power of discrimination could be used both in identification and in the determination of kinship relations. In comparison with the genetic differentiation of Turkey population with various populations (Europe, Africa, America, South Asia and East Asia), the smallest difference was observed with the European population.