From science fiction to a multimillion dollar industry: discover how genetic testing revolutionised medicine and grew into a booming business.
1902: Chromosomes are recognised as the carriers of genetic material.
1953: The iconic double helix structure of DNA is discovered.
1977: The very first DNA sequencing technique is developed.
1987: The Human Genome Project was launched with the goal of sequencing all 3 billion letters of a human genome. It was completed in 2003.
Those are some of the main turning points in the history of genetic testing and analysis. The knowledge gathered in the span of a century is utilized today to determine bloodlines, evaluate the risk for diseases, and even determine your unique dietary and fitness predispositions.
It all began with blood
In the early 1920s, scientists identified 4 blood types, based on the presence or absence of antigens A and B: A, B, AB, and O.
The ABO blood typing system made blood transfusions and organ donation significantly safer and more successful. But because blood type is inherited, it also marked the beginning of genetic testing as a tool for determining parental relationships.
A significant leap forward was made in the mid-1970s when scientists discovered a protein called the Human Leukocyte Antigen (HLA), responsible for the regulation of our immune system.
HLAs are highly polymorphic (have many different alleles), which makes them useful for high-accuracy identification, but HLA testing requires lots of blood and has to be performed within days of sample collection.
DNA profiling
In the 1980s, DNA profiling emerged. Also called DNA fingerprinting, it is a way of determining a person’s DNA characteristics, which are as unique as his fingerprints – hence the name.
Scientists developed a technique called Restriction Fragment Length Polymorphism (RFLP), which became the first genetic test using DNA.
It is a technique that exploits polymorphisms – highly variable DNA regions – to distinguish individuals, populations, or species, or to detect the locations of genes within a sequence.
This is achieved by using the enzyme restriction endonuclease, which fragments (cuts) the DNA whenever it recognises a short, specific DNA fragment.
In the early nineties, RFLP was replaced by Polymerase Chain Reaction (PCR), which enables scientists to make copies of a specific DNA sequence.
PCR imitates natural DNA replication but limits it to specific DNA sequences which we are interested in. Just like a DNA copying machine!
Because it requires a very small sample of DNA, it is widely used in forensics, where scientists often have only trace amounts of genetic material available.
PCR also has a broad medical and diagnostic application: determining gene expression, tissue typing before organ transplantation, early diagnosis of certain cancers, identifying infectious diseases, etc.
