Parentage reports (DNA analysis)

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There are different types of parentage reports , some of which are based on analyzing the DNA of the living beings involved.

application

The most common use case in humans is the verification of the father indicated by the mother, often referred to as the paternity test . Here, the man whose potential paternity is to be checked is called the putative father , a combination of words with the Latin verb putare ("to believe"); it means the father in good faith according to the old Roman legal proverb : "The father is always uncertain" (Pater semper incertus est) , in contrast to: "The mother is always certain" ( Mater semper certa est ) . From this it followed with the Romans: "Father is [only] he who is proven to be such by marriage" (Pater est, quem nuptiae demonstrant) . Since 1992, the German Civil Code has also declared in Section 1591 on motherhood: “The mother of a child is the woman who gave birth” (compare Uncertain proof of paternity , false father ).

The use of a DNA paternity analysis is subject to legal regulations in some countries, including in Germany (compare paternity in German law ).

Procedure

Samples are taken from humans

Obtaining DNA profiles is always an encroachment on personal rights . Therefore, the consent of this person must always be available or this must be replaced by a court order. The identity of the test person must be reliably checked and documented. In order to ensure usability in court, the corresponding requirements of the laws of the respective country must be taken into account.

Samples containing DNA can be obtained from almost any body material. As a rule, this is done using saliva samples (swabs from the oral mucous membrane), more rarely from blood samples or hair with hair roots.

Special features arise in the case of a prenatal parentage report .

Samples become numbers

The samples taken are first processed in the laboratory using chemical and physical methods in order to extract the DNA from the body's cells. If the DNA is available in sufficient quantity and quality, selected sections of the DNA are duplicated by the so-called polymerase chain reaction (PCR, polymerase chain reaction). These DNA segments are 1985-1998 mostly minisatellite DNA (also VNTRs = "variable number of tandem repeats" called) since mostly short tandem repeat - markers which by, STR analysis are investigated. These consist of a variable number of repetitions of a sequence of base pairs . The number of sequence repetitions is inherited and varies from person to person.

The DNA segments obtained in this way are usually marked with fluorescent dyes. In so-called capillary sequencers, their length is precisely determined in order to draw conclusions about the number of repetitions.

According to the current "Guideline of the Gendiagnostik -ommission (GEKO) for the requirements for the implementation of genetic analyzes to clarify the parentage and for the qualification of medical and non-medical experts according to § 23 Abs. 2 Nr. 4 and Nr. 2b GenDG" from 17 July, 2012 at least 15 gene locations (markers) must be examined, provided that DNA samples from father, mother and child are tested. If only samples from father and child are tested, there are extended requirements. Currently (as of 2013) gene locations such as D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, D2S1338, D19S433, CSF1PO, Penta D, Amelogenin, vWA, D8S1156, TPOX1, SEOX , D10S1248, D12S391, D22S1045 and FGA were examined. Two hereditary features or alleles are determined at each gene location . These hereditary traits are noted. A DNA profile is now available, also known as a genetic fingerprint.

Numbers become probabilities

In each examined person there are now one or two hereditary features for each gene location. These hereditary traits must generally be present at the same genetic locus as the hereditary traits of the parents, but they can also have arisen through mutation . Therefore, the meaningfulness of an ancestry certificate increases with the number of genetic loci examined and the variability and low level of mutation in the genetic traits at these genetic loci.

The closer the relationship between two people, the more certain a relationship can be established or excluded. The more information about a person or their relatives is available with certainty, the easier it is to determine the relationship of other people with this additional information.

In the most common application, the determination of parenthood, the probability can be significantly increased if the DNA profile of both parents is not only available for one parent and the child. If you know the DNA profile of a parent with certainty, you can usually determine which characteristics the child has inherited from them. The other characteristics must then come from the other parent (or have arisen through mutation).

In the case of matches or non-matches found, an expert calculates the probability that these mutations are coincidental or that they are actually based on biological parenthood. First of all, it must be checked for each individual DNA marker, with which frequency the corresponding characteristic occurs in the population. If an allele is very common, the probability of a coincidental match between two people is relatively high. However, if the common allele is rarely found in the population, the probability of a random match is low. These calculations are carried out individually for all examined DNA markers, the results are multiplied and the probability of parenthood is calculated.

Probabilities become yes / no statements

If a child and a parent do not match in at least four of at least fifteen examined markers, the paternal or maternal descent (depending on the question) is "practically excluded". There is a certain likelihood that biological ancestry may also exist in this case, but this is extremely small.

When examining 15 or more independently inherited markers, the probability of parenthood is over 99.9%, depending on the individual inherited characteristics. If there are very rare hereditary traits, the probability can be even greater. On the other hand, if there are many common hereditary traits, the probability may be lower. To increase the likelihood, additional characteristics need to be examined: With each additional match, the likelihood of parenthood increases.

Before courts in Germany and Austria, a probability of more than 99.9% is given the predicate “fatherhood practically proven”.

In general, it examines the likelihood of a child being descended from someone known compared to any other person. If, however, a decision has to be made in the case of closely related persons who can be considered as father or mother, the probabilities are much lower because the genetic relationship among the potential producers is greater than in the case of unrelated persons to be tested. In this case, more markers have to be examined until the desired probability is also achieved here.

reliability

Mix-ups, manipulations and errors during acceptance, in the mail or in the laboratory affect reliability. In addition, insufficient qualification of the laboratory can reduce the reliability. The reliability can be examined through appropriate quality controls. Therefore, since 2011 the accreditation requirement according to DIN EN ISO IEC 17025 has been in force in Germany for laboratories that offer paternity tests. Precise requirements for quality assurance and the qualification of experts have been laid down in Germany by the GEKO guidelines.

Round robin tests are organized across Europe by the IFG Münster ( GEDNAP ) and the German Society for Parent Assessment (DGAB) . In the round robin test, the participating laboratories undergo an external quality control of their DNA analyzes .

In America, certifications ensure quality. The AABB certificate has prevailed here.

Associations and clubs, the members of which mostly voluntarily undertake to comply with self-imposed quality standards, also increase quality, such as B. the Federal Association of Experts for Parentage Assessment .

comparability

The measurement results from different laboratories, especially from different countries, may differ. There is no global standard which gene locations should be investigated. There are efforts at the European level to use the same gene locations in a uniform manner.

Limits of the expert opinion

Identical twins have a DNA profile that is indistinguishable apart from mutations, so that the usual DNA test is usually not able to differentiate between them. In one case, over 1000 gene locations were examined without being able to make a decision. Nonetheless, the more genetic loci are examined, the more likely it is that differences in the DNA profile will be found.

When a person receives a bone marrow donation, the DNA that is passed on to their descendants is no longer the DNA that can be found in any sample.

history

The mechanizable, inexpensive DNA-based examination methods have been available since around 1995.

Germany

Legal position for establishing paternity

The Civil Code regulates in § 1598a that every person concerned (i.e. every child, every doubting mother and every legal father - but not the biological but not legally recognized father) has the right to carry out a paternity test. The person concerned can commission a laboratory of their choice. If a parentage report that can be used in court has not yet been available, the consent of a participant who refuses to participate will be replaced by a court order by the family court, so that a legal test can be carried out despite the refusal. The court costs for this decision are low; a lawyer is not necessary.

Parentage reports without the consent of the legal representative are prohibited by law. Upon request, they will be prosecuted as an administrative offense and punished with a fine of up to 5,000 euros for the client, and with a fine of up to 300,000 euros for the laboratory. This applies to all clients to whom German law applies, regardless of where they have the expert opinion carried out.

In Germany, according to the Genetic Diagnostics Act , prenatal examinations of paternity are only allowed after criminal offenses.

history

The above legal situation has been in effect since April 1, 2008.

Parentage reports in which the consent of both parents and the child or their legal guardians was not available, so-called secret paternity tests, were previously a major point of contention.

It has long been debated how to deal with the issue of paternity tests. Some courts saw the right to information of the alleged father (or the child who wanted to check his parentage) as a fundamental right. Since a secret test is justified in certain situations to protect the child or to protect the family, secret tests must remain unpunished. Other judges saw in secret tests a violation of the right to informational self-determination and therefore declared secret tests to be illegal. This view is particularly dubious because the child is usually legally represented by its mother, who could prevent the test out of self-interest and thereby forfeit the child's right to know his or her own parentage. However, there was always agreement that secret tests could be manipulated and therefore should not be admitted as evidence in authorities or courts.

A legal test could be prevented by refusal by one of the parties involved.

Legal position of the laboratories

According to the Genetic Diagnostics Act, parentage reports may only be offered by physicians and experts with the appropriate qualifications (natural scientists who have been working as parentage experts for many years and have completed university education). The sampling is carried out and documented by a doctor / authority / laboratory; other sampling is not permitted. Advice and clarification of those affected by the expert is also required, as is written consent for the samples to be taken and for the test to be carried out. All parties involved can revoke their consent at any time and have the right not to know.

The laboratory must be accredited from February 1, 2011 ( ISO 17025 ). In Germany, accreditations are only carried out by the DAkkS ( German Accreditation Body ) in the legally regulated area . In addition, the laboratories must take appropriate quality assurance measures. This also includes proof of successful participation in round robin tests. The conditions for sampling are specified by the laboratories and are stored in the quality management manual of these facilities.

A genetic diagnostics commission was appointed to implement the law, which deals with the contradictions to other laws, the practical implementation in medicine and science as well as the preparation of recommendations.

history

The legal situation presented above has been in effect since February 1, 2010.

Until then, there was no legal regulation of who was allowed to offer paternity tests, and it was difficult to identify reputable providers. Many providers were non-specialist (so-called intermediaries), did not have their own laboratory and sent the samples by post to the cheapest possible laboratories, often in Australia, Singapore or the Czech Republic. Medical providers did not necessarily have the scientific training necessary for execution and calculation.

Carrying out clandestine paternity tests is also classified as an administrative offense for the laboratories; fines are possible. However, private test providers only pointed out that the consent of the tested child as well as the indirectly affected mother is required and did not ask directly.

statistical data

According to a survey from 2004, 93% of men made the acceptance of a child as their own dependent on actual, biological paternity. Paternity is excluded in around 20% of the paternity tests carried out.

In 2004 around 40,000 paternity tests were carried out in Germany. In 2007 there is talk of 30,000 tests per year.

Private test vs. Authority test

The procedure is identical for all variants. A doctor or expert is always required to take the sample. Sampling at home alone in the living room is prohibited. In principle, the only difference is in the client. However, court opinions are more expensive due to the additional procedural costs.

Private laboratory or forensic medicine

All laboratories must be accredited according to DIN / EN ISO 17025 and bill the costs privately.

costs

In August 2007, a parentage assessment carried out as part of a process with the help of a DNA analysis cost around 1,000 euros for a total of three people. The JVEG sets upper limits for the costs .

In 2017, a legally usable paternity test with a reliability of 99.9% by checking at least 21 markers and taking samples with a secure identity costs from € 80 per person, for a father and a child that is € 160. This does not include any costs for sampling.

Other countries

A uniform regulation for handling secret tests within the EU is not foreseeable. In some countries they are forbidden and punishable, in others not. In Austria, secret parentage reports , for example by unmarried fathers without custody , are prohibited because they interfere with the personal rights of a child, but are not punished.

Demarcation

Parentage reports are not genetic tests in the sense of genetic diagnostics : No knowledge is gained about the characteristics of the test persons. Only the areas between the genes are analyzed. Information about defective genes and / or hereditary diseases is not obtained.

See also

Web links

 Wikinews: Federal Constitutional Court: Secret paternity tests are not permitted  - message

Individual evidence

  1. ↑ a b c https://www.rki.de/DE/Content/Kommissions/GendiagnostikKommission/Richtlinien/Richtlinien_node.html accessed on July 9, 2019
  2. ↑ http://dgab-online.de/dgab-ringversuch/ accessed on July 9, 2019
  3. ↑ http://www.vaterschaftstest.de accessed on July 9, 2019
  4. ↑ BVerfG, decision of August 18, 2010 , Az. 1 BvR 811/09, full text.
  5. ↑ OLG Stuttgart, decision of August 10, 2009 , Az. 17 WF 181/09, full text; Paragraphs 5 to 7.
  6. ↑ Section 17, Paragraph 3, No. 2 of the Genetic Diagnostics Act .
  7. ^ BGH, judgments of January 12, 2005 (PDF; 34 kB), Az. XII ZR 60/03, full text and Az. XII ZR 227/03 (PDF; 42 kB), full text.
  8. ↑ BVerfG, judgment of February 13, 2007 , Az. 1 BvR 421/05, full text.
  9. ↑ Section 26, Paragraph 2 of the Genetic Diagnostics Act.
  10. ↑ Petra Gehring : Secret paternity tests: Bioweapons in the battle of the sexes . In: topic research ( TU Darmstadt ) 2/2005, pp. 31–33.
  11. ↑ Men are for clandestine paternity tests , aerztezeitung.de
  12. ↑ Documentation: Law of the Federal Government - draft of a law to clarify paternity independent of the contestation procedure, in: Family, Partnership, Law (specialist journal) 2007, page 403
  13. ↑ Zypries wants to ban clandestine paternity tests. In: Spiegel Online . January 3, 2005, accessed January 21, 2011 .
  14. ↑ Dietmar Hipp: Cuckoo's egg in the nest . In: Der Spiegel . No. 7 , 2007 ( online ).
  15. ↑ OLG Stuttgart, decision of July 11, 2008 , Az. 8 WF 102/08, full text.
  16. ↑ Appendix 2 (to Section 10 Paragraph 1 JVEG).