Identifying DNA markers such as Short Tandem Repeats (STR) can be used to investigate genetic diversity based on levels of heterozygosity within and between populations. Allele frequencies and forensic data for STRs were obtained from a sample of 384 unrelated individuals living in Bahia, Northeastern Brazil. Thus, the present study aimed to identify the allele frequency distribution, in addition to the forensic and genetic data, of 25 STR loci in the population of Bahia. Buccal swabs or fingertip punctures were utilized to amplify and detect 25 DNA markers. The most polymorphic loci were SE33 (43), D21S11, and FGA (21). The least polymorphic were TH01 (6), TPOX, and D3S1358 (7). Forensic and statistical data were obtained through data analysis, which revealed a large genetic diversity, with an average value of 0.813 for the analyzed population. The present study was more robust than previous STR marker studies and will contribute to future research on population genetics in Brazil and worldwide. The results of this study allowed the establishment of haplotypes found in the forensic samples of Bahia State to serve as a reference in the elucidation of criminal cases and paternity tests, as well as population and evolutionary investigations.
Keywords: Brazilian population; allele frequencies; medical and population genetics; short tandem repeats; statistical genetics and genomics.