The determination of paternity has always been a historical concern. Well known is the story of Cleopatra’s son, whose paternity was attributed to Julius Caesar creating a real political problem.
At that time in history, physical resemblance was the only possible way to know if a man was the biological father of a child or not. This was the case for thousands of years, specifically until the early 1900s. For centuries people had to play the guessing game, always knowing in the back of their minds that they could never be sure.
Today, after a long evolution we have fast, reliable and accurate DNA Testing in Ireland putting an end to unnecessary guesswork, thanks to science.
The Arrival of the 20th Century
The 20th century was the century of the great leap in the evolution of paternity testing. Many scientists have devoted themselves to the search for the best indicators to arrive at the desired zero error testing.
At the beginning of the century, in 1900, the Austrian Karl Landsteiner described the ABO blood group system (type A or B antigens that may have been associated with red blood cells). At first, it was thought to be C, but later it was changed to O. Around 1915 the scientific community accepted and recognized that the way of inheriting these antigens followed the pattern that Gregor Mendel had already outlined at the end of the 19th century when he was carrying out experiments with vegetables. In 1924, Felix Bernstein elucidated this Mendelian pattern of inheritance of the ABO system.
A few years later, in 1924 in Germany, this system was used for the first time for paternity testing and it was such a success that in 5 years more than 5000 cases were processed. Nearby countries such as Austria, Italy, and Scandinavian countries quickly followed the German example.
In 1937, across the pond, the United States approved the use of this procedure for paternity cases. It was the American Medical Association that gave the green light to the technique that was becoming so famous in Europe. They were eager to begin testing, the United States did not intend to be left behind.
This way of comparing the blood groups of the alleged father, mother, and child was useful, but if the alleged father had a blood group that was common in the local ethnic group, it became more complicated to discover whether or not he was the true biological father of the child.
Since the 1940s and for 30 years, important advances were made in this area. Stetson and Levine, through various experiments, discovered the Rhesus factor (Rh) system. Although they managed to be even more precise and were able to create subgroups within the blood groups, they still had the same problem. They ruled out candidates for the biological father but did not reliably show who the biological father might be. In today’s world population, Rh positive is the most numerous.
Paternity Testing Today
The methods that were being used during those years showed that discoveries were needed to help be more accurate. When the antigens associated with white blood cells, the so-called HLA (Human Leukocyte Antigen) system, were discovered, following a Mendelian system, it became a little more precise in terms of knowing the paternity of a boy or girl.
However, 100% reliability was still not achieved and although the ground-breaking technology of DNA analysis began to be used in the late 20th century, it was still not possible to achieve anything more than a reliability of around 81%.
Today some laboratories continue to bet on old techniques, which are not completely reliable, as we have just seen. But some laboratories are still anchored in the past, not adapting to more scientifically complex techniques for various reasons.
In mid-1985, RFLP (restriction fragment length polymorphisms) appeared. This is a new technique that is much more accurate than its predecessors, as demonstrated by the thousands of positive cases it has obtained since its discovery. The restriction enzyme kit is used to cut the DNA at different previously defined points. Although it was a great revolution at the time, this technique has now become obsolete.
Nowadays, the STR technique (short tandem repeats) is considered to be the most innovative and precise method for paternity testing available. It is now possible to find reliable results to 99.999% accuracy from our paternity tests at Summit DNA Ireland.