The identification of the victims of the Linate air crash by DNA analysis

INTRODUCTION On October 8th, 2001 a small plane collided with an MD87 SAS airliner on the main runway of the Linate airport in Milan, killing all passengers, crew members and 4 employees working in a nearby hangar. Visual, odontological, anthropological, and genetic means were employed in the identification of the victims. The genetic identification was carried out through comparison of muscle samples from the victims’ remains with the reference samples from personal objects of the victims or blood/saliva samples from their relatives. Personal objects delivery and saliva sampling was accompanied by a dedicated form signed by the victim’s relatives. MATERIALS AND METHODS Phenol-chlorophorm extraction was carried out on 62 muscle samples, 15 personal effects (toothbrushes and razors), 32 saliva samples and 4 blood samples from relatives. SGM PlusTM (Applied Biosystems) or Powerplex 16 (Promega) kits were used. PCR fragments were resolved on a ABI 373A automatic DNA sequencer; Genescan 3.1.2 analysis, Gentoyper 2.0. The obtained profiles were cross-compared on Excel tables. Statistical analyses were carried out by calculating the likelihood ratio of paternity/maternity only in motherless/fatherless cases respectively, using a spreadsheet kindly provided by G. Carmody, Ottawa. Population-specific frequency data were employed. In case of direct comparison (muscle-personal object) no statistical calculations were made, as the probability of match for both Powerplex 16 and SGM Plus is sufficiently high to allow positive identification. When low LR were achieved, no extra loci were analysed as no cross-match nor half-match (paternity/maternity relationships) had been observed between all of the remaining samples. For each of the victim identified by DNA analysis a final statement was issued. RESULTS 4 out of 113 samples (muscles and reference samples) were not clearly interpretable due to allelic drop out and/or poor amplification (<150 rfu), whilst the remaining samples were well above the 150 rfu threshold and allowed positive comparisons. DNA analysis led to the identification of 12 victims and 4 body parts; DNA in combination with odontology allowed to identify a total of 27 victims. CONCLUSION The team work of pathologists, odontologists and geneticists led to the positive identification of all 118 victims in 14 days.