Impacto de la tecnología de secuencia de nueva generación (NGS) sobre el análisis genético de casos complejos en identificación de personas desaparecidas en el conflicto armado colombiano
Thesis
In Colombia, as a direct consequence of an armed conflict of more than 60 years, it is estimated that there are more than 100,000 disappeared, of which 83,000 may be associated with enforced disappearances. As part of the reparation process for the victims and, consequently, with the peace agreements with the FARC-EP reached in Havana in 2016, their bodies, once recovered, must be identified and given with dignity to their families. To this end, the National Institute of Legal Medicine and Forensic Sciences (INMLCF), as a member of the National System of Attention and Reparation for Victims, has built a model of interdisciplinary forensic work for the identification of bodies in unidentified condition (CNI ) in which genetic analyzes are a fundamental part of this model. Therefore, and taking into account the antiquity of the conflict, forensic genetics laboratories must develop strategies to face two obvious problems during the analysis of these cases, the first to obtain satisfactory genetic profiles from highly degraded bone samples and minimum concentrations. of DNA and the second, to carry out genetic checks with non-informative relatives of reference, since, in such a prolonged period, parents and close relatives have died in many of the cases. Given this scenario, we have considered as an option for cases of identification in Colombia, the NGS / MPS genome massive sequence technology, through the Illumina ForensSeq kit, and the MiSeq FGx team, given that this type of platforms allow the analysis of a large number of genomic loci (more than 200 loci), compensating for the problem of deficit relatives and additionally includes single nucleotide polymorphisms or SNP (single nucleotide polymorphisms) which increases the probability of success in the samples degraded and / or scarce, due to its small size of amplicon (60-200 bp). In the present investigation we have carried out the internal validation of the NGS test, adjusted to the INMLCF laboratories, under international quality parameters (SWGDAM, 2019) to define under what conditions and up to what limits, genetic profiles can be obtained reproducible and informative, from complex bone samples. Additionally, the genetic-population analyzes are presented, for 89 SNP-type markers, (Illumina Forenseq kit), in 3 Colombian ethno-geographic regions (Andina-Central, Pacifica and Orinoquia) of great impact in the armed conflict, due to the large number of victims that were generated there.
