GEP-ISFG proficiency testing programs: 2007 update

Abstract This year the annual GEP-ISFG proficiency test consisted of two practical and three theoretical exercises. The practical exercise included a deficiency maternity test for which blood samples from a woman and two alleged children were analyzed and a forensic case that included a cigarette butt for STR typing and two hair shafts sent specifically for mitochondrial DNA analysis, both to be compared with a reference blood sample from a suspect. In the theoretical approach of the exercise, three different proposals were offered (one included in the certificate of participation, and two optional); the most relevant was a paper challenge on mixtures prepared with the idea to review some interesting aspects of the recent ISFG recommendations on mixtures interpretation and specially the likelihood ratio method calculation under both the unrestricted and the restricted combinational approaches. A total of 122 laboratories belonging to 16 different countries received the samples, from which, 109 submitted results. Around 50% of participating labs performed both the paternity and the forensic trials, while 52 laboratories performed only the paternity test. Other working groups of the GEP-ISFG have also organized other collaborative exercises during this year. These included a collaborative exercise with a battery of STR from X chromosome to improve standardization and the first collaborative exercise on non-human (dog) mtDNA sequencing coordinated by the Sexual Chromosomes Working Group and the Non-Human Forensic Genetics Working Group of the GEP-ISFG, respectively.