In our last blog, we listed some of the latest advancements in Assisted Reproductive Technology (ART). We described the tools embryologists currently have to assist them in embryo selection. Selecting a healthy embryo helps to improve the chances for a healthy pregnancy, reduce the risk of miscarriages and the presence of a genetic disease. This technology has helped thousands of couples achieve their dream of starting a family. But what about couples who cannot form a healthy zygote? What are their options, aside from using egg and/or sperm donation?
Following a series of recent scientific breakthroughs, scientists discovered a way to correct a genetic conditions associated with disease. The two main genetic editing technologies are CRISPR and mitochondrial replacement techniques (MRT). In this blog, we will focus on CRISPR technology. MRT will be covered in our next blog.
So, what is CRISPR exactly and what are the medical and ethical implications of this technology?
Let’s start with the scientific facts:
What is CRISPR?
CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeats. This name refers to the unique organization of short partially palindromic repeated DNA sequences found in the genome of bacteria.
The CRISPR system is a natural system used by bacteria to protect themselves from infection by viruses. When the Bacterium detects the presence of viral DNA that was incorporated to its genome, it produces short RNA sequence which contains the sequence that matches the DNA of the invading virus. This RNA sequence forms a complex with a protein called Cas9, which can cut DNA at specific a location. Guided by the short bacterial RNA sequence, Cas9, the molecular scissors can cut at the exact location in the Viral DNA that matches the short RNA sequence. As a result, it will disable the virus. This video published by McGovern Institute for Brain Research at MIT demonstrates how CRISPR works.
In light of its precision and efficiency, scientists began to search for modifications of the mechanism of Cas9 to allow it to be utilized on any DNA, not just bacterial DNA and more importantly, to be able to use it on living cells.
CRISPR carries a promise that could potentially revolutionize the medical field as we know it. There are over 10,000 human diseases that are caused by a single gene, which CRISPR gene editing tool could be used to eradicate them.
Sounds like something taken out of Sci-Fi movie? Not anymore, This scientific breakthrough was published last month by scientists in the US.
The Researchers at Oregon Health and Science University in Portland used CRISPR tool to correct the harmful mutation in a gene responsible for inherited heart conditions in human embryos. The mutated gene (MYBPC3) was replaced with a copy of the gene that did not carry the mutation. The researchers found that 72% of embryos were accurately and safely corrected. This was the first successful evidence that demonstrated the feasibility of the technology.
On one hand CRISPR holds tremendous curative potential but its introduction to clinical practice has raised many ethical considerations and concerns to what could become a modern version of Eugenics, the biological enhancement of the human race.
Dr. Bentov, Juno’s reproductive specialist, weighs in, “Being able to prevent or treat a genetic disease is a notable achievement with great benefits to humanity. However, more research and strict regulations are in need before this technology could be adopted clinically”. “At Juno, we keep up to date with the latest research to make sure we offer the most advanced and safest reproductive technologies in the market.”
In our next blog, we are going to cover mitochondrial replacement technology, stay tuned!