Imagine a world where we could alter our genes similar to the cut and paste option in a word document, remove a word or sentence we dislike and insert a positive one. That's a world of endless possibilities, others may even call it magical. The question is could this imagination develop into reality? The solution is yes. The solution lies in CRISPRCas9.
Before we delve into CRISPRcas9, allow us to understand why this tool is also necessary.
As many may know, there are different types of diseases: infectious ones like Covid-19, non-communicable ones. Non-communicable diseases may further be classified into; deficiency diseases like kwashiorkor, physiological diseases like diabetes and hereditary(genetic diseases and non-genetic) diseases. Infectious diseases are usually caused by pathogens, whereas non-communicable diseases are also caused by lifestyle, environment and sometimes inheritance of a genetic disease. Genetic diseases are diseases caused by the presence of an abnormal gene or perhaps a mutation in a gene. A number of common genetic disorders are sickle-cell anaemia, Alzheimer’s, Parkinson disease, autism, cystic fibrosis. Occasionally, some of these genetic diseases are treatable or manageable, other times they're life-threatening.
It seems unfair as compared to other kinds of diseases. Getting a disease simply because you inherited an abnormal gene from your family is gloomy and devastating.
Over the years, there has been extensive research to curb the consequences of those genetic diseases and find a cure. Genetic disorders are the results of a mutation during a gene. Sometimes, the mutation doesn't cause diseases because of its structure and performance. Other times, just a change in a letter can cause deadly infections. for instance, with sickle cell, the mutation is a result of a change within the DNA sequence from a letter A to a letter T.
That is it! this is because, this gene, the haemoglobin gene is the molecule accountable for delivering oxygen to the body. Thus, the mutation causes the protein, haemoglobin synthesized(created) from the gene to be changed. this alteration disrupts the folding of the protein which eventually ends up in the formation of red blood cells which easily collapse, stiff and sickled. Red blood cells transport oxygen to tissues and organs. However, if tissue or an organ is bereft of enough oxygen, it damages eventually and dies. It may cause other diseases. If an individual is unfortunate and inherits these abnormal genes from both parents, then it becomes more serious.
However, if it's inherited from one parent, then the healthy gene from the opposite parent will work effectively and fewer consequences are going to be seen. Such individuals are termed carriers.
To fix such genetic disorders, the gene must be corrected. thanks to research, a way called gene therapy was invented. The abnormal gene was identified and isolated. The corrections were made but inserting the corrected gene back to its original place became a burden. It's like taking a sentence or paragraph from a word document and editing it. However, replacing it at its original place within the document becomes an issue. Fix it at the incorrect place and therefore the meaning changes. In humans, replacing the corrected gene at the incorrect site can result in several complications and even death because there are about 25000 genes within the human body. The probability of fixing it at the incorrect site is more likely.
In the year 2000, professor Alain Fischer and his team attempted this procedure on children who would have died anyway. It worked however, 4 of the kids developed cancers and 1 died. Others survived and scientists are still developing the technique.
To fix the problem of cutting and replacing the right gene at its original site is CRISPRcas9. Abnormal genes are cut, and on its molecular surface holds the proper gene, it pastes the proper DNA sequence and therefore the other strand of DNA copies it using the corrected sequence as a template. Then, everything returns to normal. It is simple, fast and efficient.
Genes are the blueprint for creating everything the body needs. Genes are made of DNA that instructs a cell on a way to make a protein. Proteins are responsible for our structure and performance. Basically, they're liable for how you look; short or tall, black or white, slim or fat.
YES! Viruses attack not only humans but bacteria also.
In their studies, they realized that bacteria that fight against viruses cut the viruses using the Cas9 enzyme. Afterwards, the store a part of the viral DNA in a section called CRISPR locus it forms part of bacterial DNA. Later, when the bacteria come into contact with the virus, it remembers the virus with the viral DNA attached thereto. So, the bacteria search for the part of the virus that contains the copied DNA sequence it's, using Cas9, it cuts the virus and it dies.
These two scientists then probed for the importance of this new tool. They realized that this might help in curing genetic diseases.
So, they first attach the altered gene, which is an RNA molecule along with the cas9 enzyme. The RNA molecules is a guide, it goes through the genome and finds the identical sequence. After identifying it, the cas9 enzyme cuts the DNA. The corrected gene is then inserted. The corrected gene then replaces it. But this replaces just a strand on one DNA molecule. Our DNA will then copy the information onto the opposite strand, using the corrected gene as a template. similar to a document, the incorrect word or sentence is cut and therefore the correct word or sentence is pasted immediately.
This is one of all the most effective discoveries because this might be able to treat plenty of genetic diseases and even cancerous cells. This method has been attempted on a sickle cell patient named Victoria Grey. It worked and so far, she experiences fewer symptoms than before. However, Victoria can still pass the abnormal gene to her children. This is often because, the genes were fixed within the somatic cells, all the cells within the body except the sperm and also the egg. If the changes are made in these cells, the embryonic cells, it changes everything. It means an individual’s DNA is going to be altered forever.
Scientists think that lots need to be studied before we modify the DNA of a human being forever because it's premature and therefore the consequences aren't known yet. Regardless, a Chinese scientist, He Jiankui went on to use this system on twin babies to stop them from getting HIV/AIDS. He inserted a gene that will make them resistant to HIV/AIDS because their father had AIDS. He performed this method in vitro, whilst the babies were in a petri dish yet to be transferred into the womb. Scientists thought this was unethical because the DNA of the girls are changed forever. Hence, he has been sentenced to prison for 3 years. The girls will transfer that gene to their children because this happened within the germline cells, unlike the somatic cells.
The technique worked but should this be encouraged? Others may even term it as playing God. This technology may be used to enhance our features, the popular term, designer babies. People fear that if this system is allowed, the affluent will use this system to become better in society. Their children will all have unique and robust qualities in humans. They would be tall and strong; choose any complexion they like and so on. Hence, we ask you, should this system be allowed? Before you say an enormous no, please answer this. Would you wish scientists to use this technique on your baby or siblings to save their lives? Please leave your comment and like if you enjoyed it.
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