English Speaking Working Group Research Articles

Results of the 2015 Relationship Testing Workshop of the English Speaking Working Group

Annually, members of the English Speaking Working Group of the International Society for Forensic Genetics are invited to participate in a Relationship Testing Workshop. In 2015, 64 laboratories participated. Here, we present the results from the 2015 workshop, which included relationship testing of blood samples from a mother, two children and an alleged father. Furthermore, the laboratories filled in a questionnaire concerning the laboratory strategies and routines. Finally, the laboratories were encouraged to do a paper challenge concerning the relationship between a child (boy) and an alleged grandfather with statistical calculations including results of autosomal STRs and Y-chromosomal STRs. The paper challenge showed large variations in the biostatistical calculations in cases of genetic inconsistencies observed in Y-chromosomal STR typing results.

A report of the 2009–2011 paternity and relationship testing workshops of the English Speaking Working Group of the International Society For Forensic Genetics

A report of the 2009–2011 paternity and relationship testing workshops of the English Speaking Working Group of the International Society For Forensic Genetics

Results of the 2013 Relationship Testing Workshop of the English Speaking Working Group

We present the results of the 2013 Relationship Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics. A total of 56 laboratories participated. The exercise included relationship testing of blood samples from an alleged mother and two children. Furthermore, the laboratories filled in a questionnaire concerning the laboratory strategies and routines. Finally, the laboratories were encouraged to do a paper challenge with statistical calculations including autosomal STRs and X-chromosomal STRs. In the relationship testing exercise, the two children were truly a biological child and a biological grandchild of the alleged mother. The exercise revealed that the use of X-STRs was informative and excluded the alleged mother as the mother of her grandchild. The paper challenge showed large variations in the biostatistical calculations in cases of rare events such as possible silent alleles, genetic inconsistencies and in calculations involving X-chromosomal STR genotyping results.

Results of the 2011 Relationship Testing Workshop of the English Speaking Working Group

We present the results of the 2011 Relationship Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics. A total of 62 laboratories participated. The exercise included relationship testing of blood samples from a man and two children. Assuming that the man is the biological father of both children, the laboratories were asked to investigate if the results were in favour or against that the children were half or full siblings. Furthermore, the laboratories filled out a questionnaire concerning the laboratory strategies and routines. Finally, the laboratories were encouraged to do a paper challenge with statistical calculations. The relationship testing exercise revealed that the use of mtDNA and X-STR was informative and excluded the possibility of full siblings. In the questionnaire, most laboratories (77%) indicated that a single autosomal STR kit was used in all paternity cases. However, >60% of the laboratories had three or more autosomal STR kits available for paternity testing. The paper challenge showed large variations in the biostatistical calculations in cases of rare events such as a rare allele and when a single genetic inconsistency was observed.

Results of the 2009 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics

Here we present the results of the 2009 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics. The exercise included paternity testing of blood samples from a mother, a child and two alleged fathers. The laboratories were encouraged to answer questions concerning their laboratory routines and a paper challenge was distributed in order to compare statistical calculations. A total of 62 laboratories participated. The laboratories used a total of 49 autosomal STRs and PCR-investigated VNTRs, 19 Y-chromosomal STRs, 8 X-chromosomal STRs, 7 VNTR systems investigated with RFLP, 49 autosomal SNPs and 11 mtDNA SNPs. The rate of typing and reporting errors was 0.1%.

A report of the 2002–2008 paternity testing workshops of the English speaking working group of the International Society for Forensic Genetics

The English Speaking Working Group (ESWG) of the International Society for Forensic Genetics (ISFG) offers an annual Paternity Testing Workshop open to all members of the group. Blood samples, a questionnaire and a paper challenge are sent to the participants. Here, we present the results of the 2002–2008 Paternity Testing Workshops with the objective to evaluate the uniformity of DNA-profiling and conclusions of the participating laboratories as well as to clarify tendencies in typing strategies and biostatistical evaluations of the laboratories. The numbers of participating laboratories increased from 46 in 2002 to 68 in 2008. The results showed an increasing degree of concordance concerning methods and DNA systems used and a high degree of uniformity in typing results with discrepancies in 0.1 and 0.3 % of all submitted PCR-based results. The paper challenges showed uniformity in the calculation of the weight of evidence for simple cases with straight-forward genetic constellations. However, a high degree of variation existed in complex scenarios with rare genetic constellations such as genetic inconsistencies/possible silent alleles, rare alleles and haplotypes.

Results of the 2007 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics

We present the results of the 2007 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics. The exercise included paternity testing of blood samples from a mother, a child and an alleged father. The laboratories were encouraged to answer questions concerning their laboratory routines and a paper challenge was distributed in order to compare statistical calculations. A total of 69 laboratories participated. The laboratories used a total of 41 autosomal STRs and PCR-investigated VNTRs, 22 Y-chromosomal STRs, 11 X-chromosomal STRs and 7 VNTR systems investigated with RFLP. The rate of typing and reporting errors was 0.2%.

WITHDRAWN: Results of the 2007 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics

WITHDRAWN: Results of the 2007 Paternity Testing Workshop of the English Speaking Working Group of the International Society for Forensic Genetics

Results of the 2005 paternity testing workshop of the English Speaking Working Group of the International Society of Forensic Genetics

We present the results of the 2005 paternity testing workshop of the English Speaking Working Group of the International Society of Forensic Genetics. Blood samples from an alleged father, two children and a mother were sent to the participating laboratories. The participants were encouraged to treat the case as a paternity case, and also to consider other family relationships. A total of 62 laboratories reported results. The laboratories used a total of 42 autosomal STRs/PCR-investigated VNTRs, 22 Y-chromosomal STRs, 8 X-chromosomal STRs and 8 VNTR systems investigated with RFLP. The rate of typing and reporting errors was 0.3%. The results from a paper challenge showed that some of the rare events were treated differently in the participating laboratories.

Results of the 2003 paternity testing workshop of the English Speaking Working Group of the International Society of Forensic Genetics

We present the results of the 2003 paternity testing workshop of the English Speaking Working Group (ESWG) of the International Society of Forensic Genetics (ISFG). The scenario was an alleged father, one child and the mother. All 51 participating laboratories drew the correct conclusion. The laboratories used a total of 30 autosomal and 17 Y-chromosomal PCR-based STR systems and 7 RFLP-based VNTR systems. The percentage of typing errors was 0.12% for the autosomal systems and 2% for the Y-chromosomal systems. The results from a paper challenge showed that occurrences of rare events such as mutations and possible silent alleles were treated differently among the participating laboratories. Participating laboratories reported mutational events observed in STR systems. Considerable differences between mutation rates in STR loci were reported. There were marked differences between paternal and maternal mutation rates as well as between single-step and multiple-step mutation rates.

Results of the 2001 paternity testing workshop of the English speaking working group

We present the results of the 2001 paternity testing workshop of the English speaking working group of the International Society for Forensic Genetics. In total, 36 laboratories participated. The scenario was an alleged father and two children who were known to be children of the same non-investigated mother. All laboratories drew the correct conclusion. The laboratories used a total of 58 PCR-based systems, 14 conventional systems and 10 RFLP-based systems. The workshop also included a paper challenge. The results here revealed that occurrences of rare alleles, mutations and possible silent alleles were treated very differently among the participating laboratories.

Paternity determination in criminal cases by DNA typing in South Ukraine

We report the results of the 1995 and 1996 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Haemogenetics. In 1995, 18 laboratories participated and in 1996, 21 laboratories participated. Each year, blood samples from three persons (child, mother and alleged father) were sent to participating laboratories which performed paternity testing according to their usual protocols. The results and answers to questionnaires concerning methods were compiled and are presented in this report. From the questionnaires, a general tendency to a more frequent use of polymerase chain reaction (PCR) based methods was seen. In 1996, 62% of the laboratories used PCR based methods. Ten per cent of the laboratories used only PCR based methods. The remaining 90% of the laboratories performed restriction fragment length polymorphism (RFLP) investigations of variable numbers of tandem repeat (VNTR) loci with single locus probes (SLPs) either alone or in combination with PCR based typing, multi locus probing, classical systems (ABO etc.), or serological HLA typing. In 1996, typing with classical systems was used in 29% of the laboratories. The majority of the laboratories performed RFLP typing of VNTR loci using very similar methods. The results and the inter-laboratory variations of the measured lengths of the DNA-fragments of the VNTR regions D2S44, D7S21, D7S22, and D12S11 of the trios were analysed. The overall coefficient of variation was 2.15% in 1995 and 1.43% in 1996. During the period 1991–1996, the inter-laboratory variation has decreased, most probably due to the fact that the methods have now been optimised and the majority of the participating laboratories have adopted the standardised method for RFLP typing with SLPs which was agreed upon for investigations in crime cases by the European DNA Profiling Group. In 1996, eight laboratories reported the results of PCR based typing of the short tandem repeat (STR) locus HumTH01, six laboratories reported results of HumVWA31A typing, and five laboratories reported the results of typing of the STR locus HumF13A1 and the VNTR locus D1S80. The results were concordant although the nomenclature was slightly inconsistent concerning the classification of an irregular repeat of the HumTH01 system.

A report of the 2000 and 2001 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Genetics

During the last 10 years, the English Speaking Working Group (ESWG) of the International Society for Forensic Genetics (ISFG) has once a year arranged a Paternity Testing Workshop in which blood samples as well as a questionnaire concerning laboratory strategies were distributed to the participating laboratories. In 2000 and 2001, paper challenges were included in the workshops. Here, we present the results of the 2000 and 2001 Paternity Testing Workshops. The numbers of participating laboratories were 33 (2000) and 36 (2001). A total of 36% (2000) and 31% (2001) of the laboratories submitted typing results of variable number of tandem repeats (VNTRs) investigated with restriction fragment length polymorphism (RFLP) and single locus probes (SLPs). A total of 91% (2000) and 86% (2001) submitted typing results of polymerase chain reaction (PCR) based systems. Typing errors occurred in 0.3% of the submitted PCR-based results in 2000 and in 0.1% in 2001. The results of the paper challenges showed a high degree of variation in the formulas used for calculation of the weight of evidence of rare events such as inconsistencies or possible silent alleles. The majority of the laboratories used the same formulas for calculations of frequently occurring events.

A report of the 1997, 1998 and 1999 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Genetics

We present the results of the 1997, 1998 and 1999 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Genetics. The numbers of participating laboratories were 24 (1997), 31 (1998) and 32 (1999). In 1997, all laboratories drew the correct conclusion that the alleged father was the biological father of the child. In 1998, the alleged father was the biological brother of the child and all laboratories excluded him. The scenario in 1999 was a deficiency case consisting of mother, child and the parents of the alleged father and all but one laboratory drew the correct conclusion. The percentage of laboratories routinely performing variable number of tandem repeat (VNTR) investigations using single locus probes (SLPs) and restriction fragment length polymorphism (RFLP) decreased from 83% in 1997 to 66% in 1999. In the three workshops, more than 90% of the laboratories used polymerase chain reaction (PCR) based systems. In 1999, 80% of the laboratories performing PCR, used commercially available short tandem repeat (STR) kits. Other commonly used systems were HLA and PolyMarker investigated with PCR. Conventional systems and RFLP investigations of VNTRs with multi loci probes (MLPs) were used routinely by approximately 20% of the participating laboratories. All laboratories submitting results in the three workshops used RFLP-based VNTRs or/and PCR based VNTRs/STRs. Inter-laboratory comparisons of the results showed a very high concordance. The overall coefficients of variation between the laboratories of the results of RFLP typing of the commonly used VNTRs D2S44, D7S21, D7S22 and D12S11 were 1.2–1.3%. Consistent results were obtained in the great majority of the systems investigated by PCR and typing errors counted for less than 0.3% of the PCR based results.

A report of the 1995 and 1996 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Haemogenetics

We report the results of the 1995 and 1996 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Haemogenetics. In 1995, 18 laboratories participated and in 1996, 21 laboratories participated. Each year, blood samples from three persons (child, mother and alleged father) were sent to participating laboratories which performed paternity testing according to their usual protocols. The results and answers to questionnaires concerning methods were compiled and are presented in this report. From the questionnaires, a general tendency to a more frequent use of polymerase chain reaction (PCR) based methods was seen. In 1996, 62% of the laboratories used PCR based methods. Ten per cent of the laboratories used only PCR based methods. The remaining 90% of the laboratories performed restriction fragment length polymorphism (RFLP) investigations of variable numbers of tandem repeat (VNTR) loci with single locus probes (SLPs) either alone or in combination with PCR based typing, multi locus probing, classical systems (ABO etc.), or serological HLA typing. In 1996, typing with classical systems was used in 29% of the laboratories. The majority of the laboratories performed RFLP typing of VNTR loci using very similar methods. The results and the inter-laboratory variations of the measured lengths of the DNA-fragments of the VNTR regions D2S44, D7S21, D7S22, and D12S11 of the trios were analysed. The overall coefficient of variation was 2.15% in 1995 and 1.43% in 1996. During the period 1991–1996, the inter-laboratory variation has decreased, most probably due to the fact that the methods have now been optimised and the majority of the participating laboratories have adopted the standardised method for RFLP typing with SLPs which was agreed upon for investigations in crime cases by the European DNA Profiling Group. In 1996, eight laboratories reported the results of PCR based typing of the short tandem repeat (STR) locus HumTH01, six laboratories reported results of HumVWA31A typing, and five laboratories reported the results of typing of the STR locus HumF13A1 and the VNTR locus D1S80. The results were concordant although the nomenclature was slightly inconsistent concerning the classification of an irregular repeat of the HumTH01 system.

English workshop summary

The English speaking working group was chaired by Stephen Witt, University of Swansea.