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What is Genome Editing?

The ability for scientists to change the DNA sequence of a living organism
Allows genetic material to be added, removed, or changed
The first genome editing tools were discovered in the early 1900s

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What is gene editing used for?

Gene therapies - treatments that use genome editing to prevent and treat diseases like cystic fibrosis and diabetes

Germline therapy

Change genes in reproductive cells

Somatic therapy

Change genes in non-reproductive cells

In 2015, there was a successful use of somatic therapy on a one year old girl with leukemia → it was done with a genome editing technology called TALENs

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Gene editing technologies

Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)
Transcription activator-like effector nucleases (TALENs)
Zinc-finger nucleases (ZFNs)

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CRISPR-Cas9

CRISPR is the latest genome editing technology and has proven to be more efficient and useful than past genome editing techniques
It was developed based on a bacteria’s editing system that capture part of DNA from the virus to create something called CRISPR arrays. These allow the bacteria to recognize the virus, so that when the virus does attack again, the bacteria produces RNA fragments to target the virus’ DNA. Cas9 is the enzyme the bacteria will use to cut up the virus’ DNA, to disable it.
CRISPR-Cas9 works by producing RNA segments that will bind to a specific genome sequence in DNA. Cas9 will also bind to the RNA, so it will cut the DNA when its recognized by the RNA.

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Ethical Concerns

There are so many concerns when it comes to genetically editing humans there are a few examples:

Can the embryo be edited if the parents give consent, even though it’s impossible for the embryo to give consent?
If gene editing becomes normal among the wealthy, this will increase the differences between the rich and the poor
Can genome editing be used to alter traits like height or intelligence?
Can we edit germline cells or should we not so it can’t be passed down from generations?

He Jiankui, a chinese researcher, illegally implanted genetically modified embryos into two women. Twins were later born in November 2018, he is currently sentenced to three years in jail for his illegal medical practices and was heavily fined.

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Resources

What are genome editing and CRISPR-Cas9? - Genetics Home Reference - NIH. (n.d.). Retrieved July 01, 2020, from https://ghr.nlm.nih.gov/primer/genomicresearch/genomeediting

What are the Ethical Concerns of Genome Editing? (n.d.). Retrieved July 01, 2020, from https://www.genome.gov/about-genomics/policy-issues/Genome-Editing/ethical-concerns