STRidER STRs for identity ENFSI Reference database

The European Network of Forensic Science Institutes DNA Working Group (ENFSI DNA WG) provides an updated version (V2) to the previously published 'ENFSI DNA WG STR Population Database'. The concept of STRidER (STRs for identity ENFSI Reference database) is still based on the considerations detailed in 1, but the dataset was updated to comply with the technical developments and adaptation of additional STR markers 2.

This website can be used to calculate match probabilities of DNA profiles from cosmopolitan Caucasian populations across Europe. Differences in allele proportions between populations of the different countries have been quantified by estimating Fst 3, showing that the effect is small (Fst is approximately 0.001). Nevertheless, the effect cannot simply be ignored because match probabilities of DNA profiles derived from a European database will tend to be lower than those derived from an appropriate cognate population database. In order to take account of both sampling error and population sub-structuring effects, various methods can be applied including the Balding size bias correction 4, the Balding and Nichols Fst correction 5, and an upper bound of a 95% confidence interval 6.

The task of this website is to make STRidER (STRs for identity ENFSI Reference database) generally available, so that it can be used by forensic laboratories to enable the calculation of a match probability for a sample using the above mentioned adjustment factors.

This project was supported by HOME/2010/ISEC/MO/4000001759 (STEOFRAE).

STR loci and allele nomenclature

STRidER holds STR loci defined in the specifications of the ENFSI DNA WG. These include the STR loci D3S1358, VWA, D16S539, D8S1179, D21S11, D18S51, D2S441, D19S433, TH01, FGA, D22S1045, SE33, D10S1248, D1S1656, D12S391, and D2S1338. Additional loci that may be included in commercial kits are not included in this version of STRidER, as no high quality population data are available. Therefore, those loci are dimmed in the input display.

As defined by the ENFSI DNA WG the following criteria for allele nomenclature are applied:

We defined the following allele category ranges taking the different allelic ladders into consideration:

VWA TH01 D21S11 FGA D8S1179 D3S1358 D18S51 TPOX CSF1PO D13S317 D7S820 D5S818 D16S539
10 - 23 3 - 14.3 23 - 38 16 - 47.2 7 - 19 11 - 20 7 - 28 TBA TBA TBA TBA TBA 7 - 16
D2S1338 D19S433 Penta D Penta E D1S1656 D2S441 D10S1248 D22S1045 D12S391 SE33 D6S1043 DYS391 Y indel
14 - 29 8 - 18.2 TBA TBA 9 - 20.3 8 - 17 9 - 19 9 - 20 14 - 27 5.3 - 38 TBA TBA TBA

References

1 Gill P, Foreman L, Buckleton JS, Triggs CM, Allen H (2003) A comparison of adjustment methods to test the robustness of an STR DNA database comprised of 24 European populations; Forensic Science International 131:184-96
2 Welch LA, Gill P, Phillips C, Ansell R, Morling N, Parson W, Palo JU, Bastisch I (2012) European Network of Forensic Science Institutes (ENFSI): Evaluation of new commercial STR multiplexes that include the European Standard Set (ESS) of markers; Forensic Sci Int Gen 6:819–826
3 Foreman LA, Lambert JA, Evett IW (1998). Regional genetic variation in Caucasians. Forensic Science International 95:27-37
4 Balding, DJ (1995) Estimating products in forensic identification. J. Am. Stat. Assoc. 90:839-844
5 Balding, DJ and Nichols, RA (1994) DNA profile match probability calculations: how to allow for population stratification, relatedness, database selection and single bands. Forensic Science International 64:125-140
6 National Research Council. (1996) The evaluation of forensic DNA evidence. National Academy Press, Washington D.C.
7 Bär W., Brinkmann B., Budowle B., Carracedo A., Gill P., Lincoln P., Mayr W., Olaisen B. (1997), 'DNA recommendations. Further report of the DNA Commission of the ISFG regarding the use of short tandem repeat systems.', Forensic Science International 87(3), 179-184.