Abstract
We have analysed exclusion rates in 3487 paternity tests performed in our laboratory on a population from the Russian Federation. Out of this number 3220 tests were conducted for personal information and 267 tests were directed by courts. Both court-directed and personal information tests included deficient (motherless) and complete cases.
The overall paternity exclusion rate was 23.5%. Exclusion rate for court-directed tests (19.1%) was somewhat smaller than that for personal information ones (23.9%) although no significant difference was observed between these values using χ2-test (p= 0.05). No significant difference between paternity exclusion rates in duo and trio personal information tests was also found (23.9% and 21.4%, respectively). However, duo (28.6%) and trio (13.0%) cases for court-directed tests showed significant difference when analysed by χ2-test (χ2 = 10.044, p = 0.002). Our data indicate that paternity exclusion rates in the Russian Federation are similar to those found for other countries (20–30%) when paternity was assessed by DNA analysis.
Keywords
1. Introduction
Currently, there is no generally accepted opinion on the rates of non-paternity in human populations. Reported paternity discrepancy rates differ depending on the method used to assess paternity, the type and the size of the experimental population and even whether they were obtained from a paternity testing laboratory or during routine medical examination of participants. Studies conducted before the advent of DNA testing or at its very beginning, as a rule, reported lower exclusion rates based on serological typing or analysis of a small number of DNA markers [
1
, 2
]. Once determination of the paternity status began to be routinely assessed by DNA analysis reported rates of non-paternity were significantly higher, reaching 20–30% [[3]
]. Some scholars consider that in human populations non-paternity rates are declining and constitute 2–3% [Annual Report Summary for testing in 2010. American Association of Blood Banks (2011). Available: http://www.aabb.org/sa/facilities/Documents/rtannrpt10.pdf.
[4]
], while a recent study [[5]
] proposes that in Western human populations cuckoldry rate is probably in the range of 1%. Here we report results of the largest study of non-paternity rates in the Russian Federation and one of the largest studies of non-paternity ever conducted.- Greeff J.M.
- Erasmus J.C.
Three hundred years of low non-paternity in a human population.
Heredity. 2015; https://doi.org/10.1038/hdy.2015.36
2. Materials and methods
2.1 Population
As part of a wider socio-economic study of paternity in the Russian Federation we have analysed exclusion rates in 3487 paternity tests performed in our laboratory. Out of this number 3220 tests were conducted for personal information and 267 tests were directed by courts. For all types of tests prior consent was obtained from participants. Both court-directed and personal information tests included duo (motherless) and trio (alleged father, biological mother and child) cases.
2.2 Genotyping
DNA from buccal swabs was extracted using Buccal Swabs DNA Extraction Kit (Lytech, Russia). Genotyping was performed with AmpFlSTR Identifiler Plus (Applied Biosystems, USA), PowerPlex Fusion (Promega, USA) and COrDIS Plus (Gordiz, Russia) kits. Polymerase chain reactions were performed in Applied Biosystems® 2720 and SureCycler 8800 (Agilent Technologies, USA) thermal cyclers. The products of amplification were analysed on an ABI PRISM® 3500 (Applied Biosystems) instrument. Genotypes were assigned using the GeneMapper ID-X 1.4 (Applied Biosystems) software by comparison with reference allelic ladders.
2.3 Statistical analysis
Calculations of CPI were performed according to the formulas published in [
[6]
]. For all deficient (motherless) cases an inconclusive result was issued when up to two inconsistencies were observed between DNA profiles of the child (C) and the alleged father (AF). These cases were not included in the final calculations. For all complete cases when up to two inconsistencies were observed between the DNA profiles of C and AF Familias 3 software [[7]
] was used to calculate CPI taking into account mutation rates.Familias 3 software. Available: http://www.familias.no.
XLSTAT version 2015.1.03.15464 (Addinsoft, USA) was used to perform χ2-tests
3. Results and discussion
Results of comparison between court-directed and personal information tests are presented in Table 1. The overall paternity exclusion rate was 23.5% which is significantly higher those reported in [
4
, 5
]. Exclusion rate for court-directed tests (19.1%) was somewhat smaller than that for personal information ones (23.9%) although no significant difference was observed between these values using χ2-test (p = 0.05). In both court-directed and personal information tests non-paternity rates for motherless cases were higher than those for complete cases, however only for court-directed cases this difference was statistically significant when analysed by χ2-test (χ2 = 10.044, p = 0.002).- Greeff J.M.
- Erasmus J.C.
Three hundred years of low non-paternity in a human population.
Heredity. 2015; https://doi.org/10.1038/hdy.2015.36
Table 1Results of paternity testing conducted for personal information and directed by court in a population from the Russian Federation.
| Type of test | Exclusions | Non-exclusions | Total cases | % Exclusions | |
|---|---|---|---|---|---|
| Court cases | Duo | 30 | 75 | 105 | 28.6% |
| Trio | 21 | 141 | 162 | 13.0% | |
| Total | 51 | 216 | 267 | 19.1% | |
| Information cases | Duo | 744 | 2364 | 3108 | 23.9% |
| Trio | 24 | 88 | 112 | 21.4% | |
| Total | 768 | 2452 | 3220 | 23.9% | |
We have also compared historical rates of non-paternity in children born in Russia this millennium from 2001 to 2014. Although paternity testing of these children was performed both for personal information and by court order in this paper we present only combined exclusion rates (Table 2). The observed rates of non-paternity varied from 16.9% to 28.0% averaging 24.1%. Our data do not agree with the proposed theory [
[4]
] of declining paternity exclusion rates even taking into account that our experimental population may be classified by some scientists as a low paternity confidence one [[8]
]. Based on these and our other data (not published) we estimate the rates of non-paternity in the Russian Federation to be 22–25% which agrees with reported rates [3
, Annual Report Summary for testing in 2010. American Association of Blood Banks (2011). Available: http://www.aabb.org/sa/facilities/Documents/rtannrpt10.pdf.
8
] when paternity status was assessed by DNA testing in paternity testing laboratories.Table 2Results of paternity testing of children born between 2001 and 2014 in a population from the Russian Federation.
| Year of birth | Exclusions | Non-exclusions | Total cases | % Exclusions |
|---|---|---|---|---|
| 2001 | 14 | 36 | 50 | 28.0% |
| 2002 | 13 | 44 | 57 | 22.8% |
| 2003 | 10 | 36 | 46 | 21.7% |
| 2004 | 10 | 49 | 59 | 16.9% |
| 2005 | 20 | 61 | 81 | 24.7% |
| 2006 | 22 | 72 | 94 | 23.4% |
| 2007 | 28 | 95 | 123 | 22.8% |
| 2008 | 31 | 101 | 132 | 23.5% |
| 2009 | 34 | 126 | 160 | 21.3% |
| 2010 | 49 | 158 | 207 | 23.7% |
| 2011 | 48 | 181 | 229 | 21.0% |
| 2012 | 83 | 230 | 313 | 26.5% |
| 2013 | 132 | 370 | 502 | 26.3% |
| 2014 | 126 | 392 | 518 | 24.3% |
| Total | 620 | 1951 | 2571 | 24.1% |
4. Conclusions
The overall paternity exclusion rate in the Russian Federation is estimated to be 23.5%. Although the exclusion rate for court-directed tests (19.1%) was smaller than that for personal information ones (23.9%) there was no significant difference observed between these two types of tests. Exclusion rates for motherless cases were higher than for complete cases in both court-directed and personal information tests, but only for court-directed cases this difference was statistically significant.
The rates of non-paternity in children born from 2001 to 2014 fluctuated from 16.9% to 28%. Our data indicate no decline in paternity exclusion rates of Russian children born in this millennium.
Conflict of interest
None.
References
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Annual Report Summary for testing in 2010. American Association of Blood Banks (2011). Available: http://www.aabb.org/sa/facilities/Documents/rtannrpt10.pdf.
- Recent decline in nonpaternity rates: a crosstemporal meta-analysis.Psychol. Rep. 2008; 103: 799-811
- Three hundred years of low non-paternity in a human population.Heredity. 2015; https://doi.org/10.1038/hdy.2015.36
- Parentage testing.in: Buckleton J. Triggs Ch. M. Walsh S.J. Forensic DNA Evidence Interpretation. CRC Press, Boca Ranton, London, New York, Washington DC2005
Familias 3 software. Available: http://www.familias.no.
- How well does paternity confidence match actual paternity? Evidence from Worldwide Nonpaternity Rates.Curr. Anthropol. 2006; 47: 513-520
Article Info
Publication History
Published online: September 23, 2015
Accepted:
September 19,
2015
Received:
July 24,
2015
Identification
Copyright
© 2015 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
