Genetic characterization of an X-STR decaplex system in the State of Mato Grosso, Brazil: distribution, forensic efficiency and population structure

Abstract

Studies with X-STR loci show population genetic substructure, which makes necessary the characterization of such markers in the different geographical and/or ethnic populations. Therefore, this study assessed the distribution and forensic efficiency of an X-STR decaplex system in the population of the State of Mato Grosso, as well as analysed the population structure of this State based on the aforementioned system. All X-STR markers were in Hardy-Weinberg equilibrium and linkage equilibrium, and the DXS6809 was the most informative marker. The power of discrimination value in females and males was 0.99999999995 and 0.9999994, respectively. Analysis of molecular variance indicated 1.10% (p < 0.00001) of heterogeneity among Europeans, Africans, Brazilians and other Latin Americans, and in relation to such groups, the population of the State of Mato Grosso showed lower genetic variation when compared with the Brazilian group (-0.10%, p = 0.67327). The genetic distance analysis showed lower values of F (0.0004 ≤ F ≤ 0.00331), with non-significant p value (p > 0.00024), between the populations of Mato Grosso and Mato Grosso do Sul, Paraná and the Southeast region of Brazil (except for one sample of Rio de Janeiro). F values with significant p values (p ≤ 0.00024) were obtained between the population of Mato Grosso and Iberian, African and some Latin American populations. The X-STR decaplex system proved to be extremely useful in the population of the State of Mato Grosso, and the data obtained does not show the need for a specific forensic database for this State in relation to the Brazilian populations compared in this study, except for population of Rio de Janeiro.

Applications of X-Chromosome Short Tandem Repeats for Human Identification: A Review

“…[147]) and Brazil (e.g. [148]). Although the U.S. is a multi-racial population country, the X-STRs population data available in the literature are only reporting on the four major populations viz.…”

Forensic Applications of Markers Present on the X Chromosome

“…The Investigator Argus X-12 kit was also used in this study, and 914 complete haplotypes were obtained for the markers included in the kit. Knowing the uniqueness provided by the X-STR markers, several research groups conducted studies to assess the population distribution of countries such as Brazil, Switzerland, Italy, India, Croatia, and countries on the African continent, among others [ 9 , 15 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. Table 1 lists some population studies that explore X-STR markers, published in the last ten years.…”

“…To date, the main ways to obtain this data are through consultation of publications in the PubMed database, conference proceedings of the International Society for Forensic Genetics (ISFG), and the Forensic ChrX Research website. In some countries, an organized database is available for consultation regarding haplotypes, as is the case of the Brazilian Genetic Bank of the X Chromosome (BGBX) [ 6 , 44 ].…”

“…Owing to the inheritance pattern of Chr-X, in which the daughter receives the unaltered paternal X chromosome, Chr-X markers have a high power of exclusion [ 17 ]. The X-STRs exclusion power is due to the difference in the number of alleles when compared to autosomal alleles in male individuals [ 44 ].…”