Paternity testing
From Wikipedia, the free encyclopedia
A paternity test is conducted to prove paternity, that is, whether a man is the biological father of another individual. This may be relevant in view of rights and duties of the father. Similarly, a maternity test can be carried out. This is less common, because at least during childbirth, except in the case of a pregnancy involving embryo transfer or egg donation, it is obvious who the mother is.
This can be achieved by DNA analysis of the three individuals, although older methods have included ABO blood group typing, analysis of various other proteins and enzymes, or using HLA antigens. The current techniques for paternity testing are using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). For the most part however, DNA has all but taken over all the other forms of testing.
The DNA of an individual is almost exactly the same in each and every somatic cell. Sexual reproduction brings the DNA of both parents together randomly to create a unique combination of genetic material in a new cell, so the genetic material of an individual is derived from the genetic material of their parents. This genetic material is known as the nuclear genome of the individual, because it is found in the nucleus.
Comparing the DNA sequence of an individual to that of another individual can show if one of them was derived from the other or not. Specific sequences are usually looked at to see if they were copied verbatim from one of the individual's genome to the other. If that was the case, then this proves that the genetic material of one individual could have been derived from that of the other (i.e.: one is the parent of the other). Besides the nuclear DNA in the nucleus, the mitochondria in the cells also have their own genetic material termed the mitochondrial genome. Mitochondrial DNA comes only from the mother, without any shuffling.
Proving a relationship based on comparison of the mitochondrial genome is much easier than that based on the nuclear genome. However, testing the mitochondrial genome can only prove if two individuals are related by common descent through maternal lines only from a common ancestor and is thus of limited value (for instance, it could not be used to test for paternity).
Michael Gilding, a sociologist at Swinburne University of Technology in a study, found the incidence of misattributed paternity was 1% of all paternity tests[1][2].
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[edit] Legal issues
In the UK, there were no restrictions on paternity tests until the Human Tissue Act came into force in September 2006. Section 45 states that it is an offence to possess without appropriate consent any human bodily material with the intent of analyzing its DNA. Legally declared fathers have access to paternity testing services under the new regulations, provided the putative parental DNA being tested is their own.
Tests are sometimes ordered by courts when proof of paternity is required. In the UK, the Department for Constitutional Affairs accredits bodies which can conduct this testing. The Department of Health is also in the process of updating its voluntary code of practice on genetic paternity testing.
[edit] See also
[edit] References
- ^ "Paternity fraud an urban myth: study" Sydney Morning Herald, 29 June 29 2005 - 6:19PM accessed 16 November 2006
- ^ Abstract "Rampant Misattributed Paternity: the Creation of an Urban Myth", People and Place, vol 13, no 2, 2005 accessed 16 November 2006
[edit] External links
- [1]: The HTA's code of practice on Consent
- Recovering the Romanovs: an interactive website showing how mitochondrial DNA comparison was used as a maternity test in a very interesting case.
- [2] Definitive Paternity Test Glossary.
