Genetic modification, or genetic engineering, is at the dawn of a revolution that could transform living beings as we know them today, due to a new process called CRISPR-Cas9.
CRISPR-Cas9 or Clustered Regularly Interspaced Short Palindromic Repeats is the new tool for genetic modification. Its basic principle is to cut DNA sequences and introduce modifications into them.
Discovered in 1997 by using bacterium, CRISPR-Cas9 could only be tested on human embryos since 2016 in the United Kingdom. In August 2016, China and the United States authorized the first clinical trials on adult men.
If CRISPR-Cas9 is at the forefront of research on genetic modifications, it is because the process could stop certain diseases such as cancer or modify the genetic code of embryos.
What is genetic modification ?
Genetic engineering is the modification of the code of life called DNA, which stands for Deoxyribonucleic acid. Information about the characteristics of a live being is encoded in the structure of the DNA molecule. Any changes made to that code will change the being carrying those genes.
Genetic engineering can be applied to any living being, from a plant to a human. The earliest genetically modified animal, a mouse, was born in 1974.
Until recently, gene editing was extremely costly, complicated and took a long time to do. This is where CRISPR-Cas9 enters the scene and revolutionized genetic engineering.
Costs related to experiments have shrunk by 99%, and instead of taking a year it now only takes a few weeks. Gene editing also got way more precise. Since the technology is rather simple to put in place, basically everybody with a lab can do it. In other words : CRISPR-Cas9 has the potential of changing humanity forever.
To put in into perspectives, if the old technic of modifying genetics was like using a map, the new technic is like using a GPS.
What are the issues concerning CRISPR-Cas9 ?
CRISPR-Cas9 is still a new technology and one thing is for sure: it isn’t infallible. Scientists know that one wrong edit could trigger unwanted modifications that could then be passed onto future generations.
More specifically, scientists fear mosaicism, a state where some cells are affected by changes and others are not. This could have serious consequences on an individual since the degree of mosaicism can indicate the severity of symptoms associated with a genetic disease.
In a worst case scenario way of thinking, scientists are afraid of the harmful and irreversible consequences if the CRISPR-Cas9 process ever falls into the wrong hands.
Genetic modification still raises ethical issues both within the scientific community and among the general public. We are already pre-selecting humans based on their genetic conditions. Tests exist to detect genetic diseases in fetuses. For example, in Europe, 92% of pregnancies where down syndrome is detected are terminated.