Analysis of Linkage for Ten X-STR Markers in a Rio de Janeiro (Brazil) Three-Generation Family Sample

Roberto Chan, Elizeu Fagundes de Carvalho, Juliana Gozi de Aquino, Dayse Aparecida da Silva, Gisele Lôbo-Hajdu

Coordena??o de Astronomia e Astrofísica, Observatório Nacional, Rio de Janeiro, Brazil.
Department of Genetics, State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil.
DNA Diagnostic Laboratory (LDD), State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil.

DOI: 10.4236/ojgen.2014.43025                

Abstract

Recently, typing of polymorphisms on the X chromosome has become a standard technique in forensic genetics and a growing number of short tandem repeats (STR) has been established in this chromosome related to genetic population studies. Knowledge of marker recombination is very important especially when the X chromosome typing is used in forensic kinship analysis. It is known that the meiotic recombination is not a simple function of the physical distance between segments of the DNA but the recombination events between them tend to be clustered at special regions of the chromosome. Information on the rate of recombination among markers can be gathered by studying families through several generations. In this work we have typed DNA samples of pedigree consisting of nineteen families in Rio de Janeiro, constituted of grandfather, mother and grandson, and in some cases grandmother and aunt, and reported the recombination of 10 STR markers of the X chromosome. The study of the linkage analysis using the LOD score has shown that the marker pairs DXS8378-DXS7423, DXS7132-DXS9898, DXS7132-GATA172D05 DXS9898-DXS7133 and DXS6809-DXS7133 are not transmitted in a random way, during a recombination event.

Keywords

X-Chromosome STR Markers, Recombination, Probability of Linkage, LOD Score

Conflicts of Interest

The authors declare no conflicts of interest.

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