The genetic identification of dead migratints in the Mediterranean sea: the Lampedusa 2013 Shipwreck

On October, 3rd 2013 a boat packed with more than 500 migrants coming from the Horn of Africa sank a few kilometres off the shore of Lampedusa, a small island in the Mediterranean Sea, causing the death of hundreds of persons. Biological samples were collected from the corpses and putative relatives of the victims were reached through an international call. Genetic profiles based on 16 autosomal STRs were obtained. The final genetic database included 363 victims and 43 reference persons from 36 families, missing 35 first degree and 6 second degree relatives. A blind search approach was applied to look for parent-child (PC) and full sibling (FS) pairs, both among the victims and between reference persons and victims. Both the Identity-by-State (IBS) and the Identity by-Descent (IBD) statistics were used. LR and Posterior Probability calculations were carried out by the DVI module of the Familias3 software. The blind search analysis detected some familial groups within the victims, two of which were connected to reference persons. The identifications were confirmed by computing pedigree LRs and posterior probabilities, based on information provided by the relatives. Victim-relative pairs who did not meet the posterior probability threshold required for issuing a match report were further analysed by additional autosomal STRs and lineage markers (Y-STRs and mtDNA). Some critical points emerged, especially concerning the lack of available population data from the Sub-Saharan area and the importance to collaborate with other forensic experts in the identification process. In conclusion, 32 victims were identified by kinship analysis; they included 83% of the first-degree missing relatives (PC or FS) and 50% of the second-degree missing relatives.