X-STRs as a tool for missing persons identification using only siblings as reference

Abstract

Although the most suitable people for the identification of missing persons are the parents and/or children of the disappeared, often these relatives are not available, the only alternative being the siblings. Research of biological relations between siblings and half siblings is commonly based on the use of autosomal markers; however, in some cases, the legally stipulated probability of likelihood ratio (LR) (≥0.9999) cannot be reached. This is the main reason, why it is important to consider the use of other markers such as those linked to the sex chromosomes (X and Y). In this study, we focused on the usefulness of X chromosome STRs for the establishment of relationships between siblings, we propose the implementation of them routinely in the identification of missing persons, a case type which in Colombia has increased due to the last decades of armed conflict.