Development of two multiplex PCR systems for the analysis of 14 X-chromosomal STR loci in a southern Brazilian population sample

Abstract

We developed two multiplex systems for the coamplification of X-chromosomal short tandem repeats (STRs). X-Multiplex 1 consisted of DXS6807, DXS6800, DXS7424, DXS101, GATA172D05 and HPRTB and X-Multiplex 2 consisted of DXS8378, DXS9898, DXS6801, DXS6809, DXS6789, DXS7133, DXS8377 and DXS7423. In addition, we present allele frequencies for these loci in a south Brazilian population comprising 124 females and 141 males and haplotype frequencies of linked markers for males. Hardy-Weinberg equilibrium (HWE) was tested in the female sample and no significant deviations were found after applying Bonferroni's correction. Linkage disequilibrium (LD) tests were performed for all pairs of loci and three significant results, out of 91 pairwise comparisons, were obtained. We did not find any evidence of linkage disequilibrium between close or linked markers. The power of discrimination in females (PD(F)) varied between 0.832 for DXS6801 and 0.987 for DXS8377. DXS6801 was the least informative marker (PIC = 0.605), while DXS8377 was the most polymorphic (PIC = 0.911), followed by DXS101 (PIC = 0.872). Genetic distances were estimated for each STR marker applying the calculation of F (ST) between our total sample and other studies from Brazil, Europe, Asia and Africa. The most distant populations were Japan, Korea, China, Ghana and Uganda.

X chromosomal recombination—A family study analyzing 26 X‐STR Loci in Chinese Han three‐generation pedigrees

“…X chromosomal (X‐STR) markers have been shown to be a powerful tool for solving complex kinship cases, especially in cases with female offspring and missing alleged father, or in kinship analysis involving large and incomplete pedigrees . In recent years, more and more X‐STR systems have been developed in the field of population genetics and forensics . However, a simultaneous analysis of genetic markers located on the same chromosome requires precise knowledge, not only of the allele and haplotype frequencies, but also of the genetic linkage aspects.…”

Autopsia en muertes por Covid-19: análisis y recomendaciones a través de una revisión

“…Como en el resto del genoma humano, los marcadores STRs son abundantes a lo largo del cromosoma X con una densidad comparable a los STRs autosómicos. Hasta la presente fecha se han identificados 55 STRs en el cromosoma X y se han caracterizados en más de 50 poblaciones (http://www.chrx-str.org/) de estos 55 X-STRs, 28 han sido utilizados con fines forenses [7][8][9][10][11] . El objetivo de este trabajo fue caracterizar secuencias de tipo STR del cromosoma X (DXS8378, DXS9902, DXS7132, DXS9898, DXS6809, DXS6789, DXS7133, GATA172D05, GATA31E08 y DXS7423) en una muestra de la población del Estado Zulia, Venezuela.…”

Aplicabilidade do cromossomo X no DNA forense

“…O polimorfismo presente nesse cromossomo vem atraindo cada dia mais a atenção de pesquisadores. Inúmeros estudos na população brasileira demonstraram que vários marcadores moleculares situados no cromossomo X já são validados para uso forense, sendo que estes apresentam resposta no que tange sobre a variabilidade desses polimorfismos na população (CAINÉ et al, 2007;CAINÉ et al, 2010;GUSMÃO et al, 2009;LEITE et al, 2009;MARTINS et al, 2008a;MARTINS et al, 2009;MARTINS et al, 2010a;MARTINS et al, 2010b;PENNA et al, 2011;RODRIGUES et al, 2010;RODRIGUES et al, 2011;SILVA et al, 2010;TAVARES et al, 2008). Na rotina forense, os marcadores do tipo STR mais utilizados são os localizados nos cromossomos autossômicos e no Y (TOMAS et al, 2015).…”