News from IBE (CSIC-UPF) and CEXS-UPF
Through the analysis of a combination of standard genome markers, forensic geneticists are able to compare biological traces at crime scenes, identify the remains of a missing person, or check whether a man is the biological father of a child. One of the main limitations of these studies is usually the degradation of DNA samples. In the process of identifying missing persons, if the only relatives alive are distant relations, obtaining a clear answer can be difficult.
This is often the case in the identification of individuals buried in Spanish Civil War mass graves. A technical solution to this problem lies in the utilization of massive sequencing techniques, as they enable to increase the number of genetic markers which can be analyzed simultaneously, as well as to extract more information from each of them. When many highly informative markers can be analyzed, even if a large fraction of those is lost to DNA degradation, sufficient information remains to conclusively identify the remains of a missing person; this large number can also compensate the loss of information when only distant relatives are available to provide a match.
In a pioneer study in Europe, published today in Forensic Science International: Genetics magazine, a group of researchers led by Ferran Casals from dCEXs-UPF and Francesc Calafell from IBE (CSIC-UPF), has used these new technologies to provide reference databases for two local populations, Catalans and Spanish Roma. The results show the huge amount of information that the massive sequencing can provide, and that could be used to resolve difficult cases.
Casals et al. Forensic science international: Genetics (2017). Length and repeat-sequence variation in 58 STRs and 94 SNPs in two Spanish populations. Vol 30, p 66–70. https://doi.org/10.1016/j.fsigen.2017.06.006