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Saad Ullah Siddiqui

DNA editing and genome editing allow researchers to modify the genes of living organisms. Genome editing in humans may help prevent genetic disorders and diseases.

Genome Editing

Introduction

Even though the technique is still being studied, gene therapy has proved its potential to positively contribute to managing human diseases for some years now. Gene therapy, essentially, is gene modification either through deletion or replacement of erred genes or by adding new ones aimed to treat diseases or improve your immunity.

Genome editing is a type of gene therapy. It includes the development of techniques that generate molecular tools for cutting the DNA of genomes at exclusive points, which allows targeted changes in the DNA sequence. Recently, a lot of relevant methods have been introduced and successfully used in clinical applications<a href="#accordion">[1]</a>. 
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Scientists make use of different technologies to make alterations in physical traits, like eye color, and disease risk. These technologies mimic scissors, allowing them to cut the DNA at a particular spot, and then remove, add, or replace it<a href="#accordion">[2]</a>.

The first genome editing technologies were introduced in the late 1900s. A new genome editing tool called CRISPR, which was invented recently in 2009, has made it extremely convenient for scientists to edit DNA. CRISPR is a popular choice among many scientists because it&rsquo;s simpler, faster, cheaper, and more efficient when compared to older genome editing methods<a href="#accordion">[2]</a>. 
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Understanding the Genome Editing for Disease management

Among numerous approaches to genome editing that have been introduced, a fairly popular one is CRISPR-Cas9, which is short for Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein 9. The CRISPR-Cas9 system has been the reason for a lot of excitement in the science community as it is faster, cheaper, more accurate, and more efficient when compared to other genome editing methods. CRISPR-Cas9 was essentially inspired by the bacteria&rsquo;s physiological genome editing system that it used for its own defense.

When a bacterium is infected with viruses, it entraps a fragment of the viruses&#39; DNA and inserts them into its own DNA in a particular fashion to create portions called CRISPR arrays. The CRISPR arrays then make it possible for the bacteria to &quot;remember&quot; the viruses (or the ones related to them). This is a preventive mechanism for any recurrent attack.

If the viruses attack the bacteria again, the bacteria can identify the virus by the production of RNA segments from the CRISPR arrays. The bacteria then make use of the Cas9 or a similar enzyme to cut the DNA apart, which in turn leads to the disability of the virus. 
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Scientists used this immune defense system to edit DNA. They did it by creating a small piece of RNA with a short &quot;guide&quot; sequence that binds itself to a particular target sequence in a cell&#39;s DNA. This is equivalent to the RNA segments the bacteria produces from the CRISPR array. When it makes its way into the cells, the guide RNA remembers the DNA sequence and the Cas9 enzyme cuts the DNA at the precise location, just like the procedure in bacteria.

While Cas9 is the enzyme that is frequently used, other enzymes such as Cpf1 may also be used. As soon as the DNA is cut, scientists use the cell&#39;s own DNA repair machinery to alter pieces of genetic material, i.e., to add or delete, or to replace a segment of the DNA with a customized DNA sequence<a href="#accordion">[3]</a>. 
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Genome editing tools can help scientists prevent diseases that are caused by mutations in the genome.

Annually, over 1 million people globally die due to vector-borne diseases, like <a href="https://merisehat.pk/disease/malaria">malaria</a>, yellow fever, <a href="https://cmsapi.merisehat.pk/disease/dengue-hemorrhagic-fever-dengue-shock-syndrome">dengue fever</a>, and sleeping sickness. Vector-borne means these infections are transmitted by the bite of infected mosquitoes, ticks, triatomine bugs, sandflies, and blackflies. 
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Researchers are currently working on different ways that gene editing tools can help break the severe impact of these diseases. For instance, with the help of CRISPR-Cas9 technology, scientists have been able to invent what they term &ldquo;designer&rdquo; foods!

This includes using gene editing techniques to produce a new type of waxy corn, which is high in starch and important for multiple industries like the food industry and the paper industry. Besides, genetically modified crops may help to reduce deaths due to malnutrition; nearly 50% of all the deaths globally in children under the age of 5 are because of malnutrition. 
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Researchers can also make use of CRISPR-Cas9 to develop new variants of food that are essentially pest-resistant, drought-resistant, or more nutritious. In contrast to the traditional plant breeding technique, CRISPR-Cas9 allows scientists to introduce a gene from a related wild plant into a domesticated variety. When this modified variety reproduces, the new plant will not have the unwanted traits.

Gene editing in agriculture is able to proceed more quickly than research in people as there is no need for lab, animal, and risky human clinical trials<a href="#accordion">[4]</a>. 
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Conclusion

Genome editing raises ethical concerns, including how safe the procedure is to be considered as an option for live humans. Other ethical questions that researchers must address are<a href="#accordion">[2]</a>:

<ol>
	<li>Is It Ethical To Use Gene Therapy On An Embryo? It is the earliest stage of pregnancy after fertilization and, therefore, humanly impossible to get permission from the embryo. Somebody else is calling the shots for the yet-to-be-born child. So, is that enough? 
	&nbsp;</li>
	<li>What If Gene Therapy Becomes Too Expensive that it is out of the reach of the common man and only the elites can access and afford it? 
	&nbsp;</li>
	<li>What If Genome Editing Is Used For Enhancing Traits that are not important for health, such as athletic ability or height? 
	&nbsp;</li>
	<li>Editing The Genomes Of Germline Cells means that these alterations will occur in generations to come who will all have the same traits. Should scientists be given that power? 
	&nbsp;</li>
</ol>

It might not be the age of Ultron, but it is necessary that moving forward diseases are prevented rather than treated. That said, there should be some regulations and scientists should proceed with caution. 
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Key takeaways

<ul>
	<li>Gene therapy, essentially, is either the deletion or replacement of erred genes or the addition of new ones in order to treat diseases or improve immunity.</li>
	<li>Genome editing has had some advances over the years, including the development of techniques that generate molecular tools for cutting the DNA of genomes at exclusive points which allows targeted changes in the DNA sequence.</li>
	<li>Genome editing technologies enable scientists to make alterations in human DNA which, in turn, leads to alterations in physical traits, like eye color, and disease risk.</li>
	<li>The first genome editing technologies were introduced in the late 1900s. A new genome editing tool called CRISPR was invented in 2009, making it extremely convenient for scientists to edit DNA.</li>
	<li>Among numerous approaches to genome editing that have been introduced, CRISPR-Cas9 is quite popular.</li>
	<li>The CRISPR-Cas9 system has been the reason for a lot of excitement in the science community as it is faster, cheaper, more accurate, and more efficient</li>
	<li>While Cas9 is an enzyme that is used mostly, other enzymes like Cpf1 may also be used</li>
	<li>Even though not every disease is due to mutations in the genome, some are. Genome editing tools can help scientists in preventing those diseases.</li>
	<li>Gene editing technique is also used to produce a new type of waxy corn. which is high in starch, and has multiple uses in food and other industries.</li>
	<li>Genetically modified crops may also help to reduce deaths due to malnutrition, which cause nearly 50% of all deaths globally in children under the age of 5. 
	&nbsp;</li>
</ul>