Between country comparison of a large Caucasian STR database collected as part of the Standardisation in DNA Profiling project

Abstract

Background: Standardisation in DNA Profiling (STADNAP) was a project funded by the European Union between 1998 and 2000. One aim was to collect a large amount of frequency data for all the loci being used at the time. The purpose was to provide frequency information and to examine if there was any between country variability. Methods: A request for short tandem repeat (STR) genotype information was sent to 165 laboratories known to be working in the field, either as criminal or paternity practitioners. A detailed questionnaire was included so that information about the laboratory's quality practices and the typing methodology they used could be examined with the data. An exact test was used to examine the frequency data set each locus and anomalous patterns examined. Results: Thirty-four laboratories provided genotype data from over 20,000 Caucasian individuals, with 95% of the information originating from within Europe. Twenty-nine different STRs were reported, but larger amounts of data were generally seen amongst those loci available in available commercial multiplexes. Rare intermediates were reported in all systems except VWA, TPOX and D16S539. The exact test revealed significant differences in those loci related to the use of older technologies, where difficulties can be experienced in distinguishing alleles that differ by one base pair.