DNA typing for the identification of eight victims of Spanish Civil War reprisals in the Canary Islands: The case of "the Fuencaliente thirteen" mass graves (Fuencaliente, La Palma)

Abstract

During the Spanish Civil War (1936-1939), the Canary Islands suffered one of the highest levels of repression by the insurgent side, even though there were no battles in the islands. More than 50 people were killed in the island of La Palma between July 1936 and June 1937. The Association for the Recovery of Historical Memory in La Palma, made up of relatives of people who went missing during the Civil War, located the Fuencaliente mass graves in 2004. The excavation process recovered eight skeletal remains. The aim of this work was the genetic identification of these reprisal victims.In general, obtaining nuclear DNA profiles from old skeletal samples is known to be difficult. Due to the age and conservation conditions, this was the case for the Fuencaliente remains. For these reasons, we firstly attempted to analyze the mitochondrial DNA (mtDNA). Although mtDNA control region sequences were obtained for the eight skeletal remains, the limited number of possible maternal relative donors complicated identification based only on mtDNA.Taking into account the problems in establishing identity by using mtDNA, a few years later we were presented with the possibility of analyzing nuclear DNA using the new PrepFiler Express BTA (TM) Forensic DNA extraction methodology. This extraction protocol, in combination with the new AmpFlSTR (R) NGM (TM) PCR Amplification Kit (Applied Biosystems), allowed us to obtain full nuclear DNA profiles for the eight victims.In conclusion, the use of specific protocols designed for old DNA samples, such as PrepFiler Express BTA (TM) Forensic DNA extraction and AmpFlSTR (R) NGM (TM) PCR amplification kit seems to be crucial for obtaining full nuclear profiles that allow statistically significant identification of the putative relatives.