As a biology expert would say: “ genetic markers never lie “. Today, a paternity test, which is done by comparing the child’s genes with those of the presumed father, provides a 99.9% certainty result.
Blood group paternity: a linked story
The ABO system or the classification of blood groups
After the First World War, progress in surgery and on the knowledge of blood were spectacular, because of the experience of doctors during the conflict. There blood transfusion, the rules of compatibility between certain groups, the rhesus factor… all this was unknown before the war of 14-18. It was at this time that the existence of the four blood groups was identified:
- Blood group A
- Blood group B
- Blood group AB
- Blood group O
The first blood group paternity test
The evolution of testing of blood group paternity began in 1920. Even if we had not yet had knowledge of the genotype of each individual, it was possible to have a lead on the parentage of a newborn, by taking a blood sample from the alleged father and the child.
The different paternity tests over time
Serological tests
About ten years later, in the 1930s, it was the discovery of serological tests. They returned to the forefront with the advent of Covid-19 and even if the procedures and techniques, as well as the equipment used, have evolved, the principle has remained the same. A blood sample must be taken to observe certain specific proteins indicating the particularities of the parentage group.
HLA tests with blood group paternity
THE HLA system, abbreviation of English human Leukocyte antigen (human leukocyte antigen), is different for each individual, except in identical twins. This part of the genetic code was discovered in the 1970s. Observations are made on a blood sample taken from the subject and it is very effective in determining the paternity of a newborn with a safety rate of up to 90%. %. Often, we used the HLA test in combination with blood group determination.
The first real DNA tests
It was in 1980 that biology really spoke of DNA test. Genetic testing has made a big leap thanks to the more precise discovery of the characteristics of deoxyribonucleic acid in our cells. Each individual has genes that they inherit from their parents, which means that a newborn has 50% of the genetic characteristics of his father. At that time, blood sampling was still necessary.
The PCR genetic test
THE PCR test, from English Polymerase Chain Reaction, is also a process discovered in the 90s, but which has become famous again with Covid-19. However, it is a process that also allows a paternity test to be carried out, with a very low percentage of uncertainty. The biggest breakthrough in biology with this type of analysis, it is not as invasive as a blood transfusion or the use of a needle to determine the blood group. It only takes one saliva sample to be able to observe the genes of each individual.
After the 2000s: the discovery of specific genes and DNA sequencing
Human DNA can be expressed in a very long sequence of letters. The first SNP paternity tests, for Single Nucleotide Polymorphism (single nucleotide polymorphism), emerged in the 2000s. The nucleotide chain is analyzed to compare the similarities in the genes of the father and the newborn. In 2010, it was the opportunity to do the DNA sequencing of each individual.
The evolution of DNA tests in France
What does the law say about Genetic Testing in France?
THE genetic test in France should not be undertaken lightly, as if taking a blood sample to find out your grouping. Gene sequencing, for each individual who wants to do it, whether this concerns a future mother who wants to know the paternity of her child or to know the flaws in her immune system, we must respect the law. Only a judge can order the launch of analysis procedures and this must be done with the consent of the person to whom we are going. take the genes.
What do French people who want to know the secret of their genes do?
Screen for hemolytic disease, determine the compatibility of a organ donor or even know the risks of having the type 1 or 2 diabetes, only a few laboratories are authorized to do genetic testing. The best thing for individuals who want to do this is to seek the services of a lawyer to launch the procedures. THE pregnant women who want to know if the man who shares their life is responsible for their pregnancy, must go through irregular procedures, if they do not go through the judge.