CRISPR Cas9 is a genome editing technique that uses the Cas9 enzyme to cut DNA at specific locations. In 2018, Dr. He Jiankui conducted the first human genome editing trial using CRISPR Cas9 to modify embryos' genes in an attempt to make them resistant to HIV. This resulted in the birth of twin girls known as "Nana" and "Lulu". However, Dr. He's experiment was highly controversial and considered unethical due to safety risks. While genome editing holds promise for treating disease, more research is needed to address ethical concerns before making heritable genetic changes.

1. CRISPR CAS9
By SHAHD ALAKWAA
And The Story Behind CRISPR Babies

2. OUTLINES
• Introduction
• How Genes Are Edited ???
• CRISPR Cas9 System Use In Genome Editing
• How Does CRISPR Cas9 Work???
• CRISPR Babies
• Ethical Issues About CRISPR
• Implications Of Genome Editing
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3. Why do we need genome editing?
• For research: to change the DNA in cells or organisms to
understand their biology and how they work.
• For biotechnology: in agriculture to genetically modify crops to
improve their yields and resistance to disease and drought, as well
as cattle that don’t have horns.
• To treat disease: to modify human blood cells to treat
leukaemia and AIDS. Also to treat other infections (such as MRSA)
and simple genetic conditions (such as muscular dystrophy).
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5. Introduction
DNA editing in general
▪ Genome editing with engineered
nucleases (GEEN) is a type of genetic
engineering in which DNA is inserted,
deleted or replaced in the genome of
a living organism using engineered
nucleases, or "molecular scissors“.
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6. How does genome editing work?
•It uses a type of enzyme called an ‘engineered nuclease’ which cuts
the genome in a specific place.
•After cutting the DNA in a specific place, the cell will naturally repair
the cut.
•We can manipulate this repair process to make changes (or ‘edits’) to
the DNA in that location in the genome.
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7. • Engineered Nucleases are made up of two parts:
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8. Genome Editing Systems
•There are different types of engineered nuclease. They all contain a
Nuclease part to cut the DNA, and a DNA-targeting part to recognise
the DNA sequence they cut.
•They differ in how they recognise the DNA to cut:
• RNA-based: contain a short sequence of RNA that binds to the
target DNA.
• Protein-based: contain a protein that recognises and binds to the
target DNA.
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9. What is CRISPR-Cas9 system?
• CRISPR ‘Clustered Regularly Interspaced Short Palindromic
Repeats’.
• Cas9 stands for CRISPR-associated protein 9, and is the nuclease part
that cuts the DNA.
• CRISPR-Cas9 is the most common, cheap and efficient system
used for genome editing.
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It is an RNA-based genome editing system
 Originally discovered in bacteria that use this system to destroy
invading viruses.
Cas9 enzyme from Streptococcus pyogenes, is the most well-
characterized and widely used Cas9 in genome engineering.

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13. Timeline of Human genome editing
■ March 2015: Chinese researchers became the first to edit
genes in a human embryo
■ June 2016: He Jiankui launches a project to edit genes in
human embryos, with a goal of a live birth.
■ March 2017: He starts recruiting couples (each with an HIV-
positive father) for the experiment.
■ Early November 2018: gene-edited twin girls are reportedly
born, and a second pregnancy with a third gene-edited
embryo is established.
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14. Timeline of Human genome editing
■ November-December 2018: China’s National Health
Commission orders an investigation into He’s work.
■ January 2019: He is censured by the Guangdong's health
ministry and fired from his university.
■ 18 March 2019: a World Health Organization committee will
meet to see the guidelines for human gene editing
■ August 2019: third gene-edited baby expected.
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15. CRISPR BABIES
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16. CRISPR babies
■ A Chinese biophysics researcher in Southern University of Science and
Technology, Dr. He Jiankui conducted a genome editing trial and the
result was revealed in November 2018: The First in the world “DNA -
edited” girl twin known as “Nana” and “Lulu”.
■ The aim of the experiment was to make the embryos resistant to
some strains of HIV
■ He stated that the two girls were born healthy with no abnormalities.
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17. CRISPR babies
■ He’s work involved creating embryos from a healthy mother and a
HIV-positive father and applying the gene editing tool CRISPR-Cas9 to
those embryos to remove the CCR5 gene which allows HIV into cells.
■ He claimed that whole-genome sequencing of the newborns’ cord
blood showed that no other parts of the genome have been altered.
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20. Ethical issues about crispr cas9
■ Due to the SMALL possibility of off-target effects and mosaicism
(when some cells carry the edit but others do not), safety is of
primary concern.
■ Researchers and ethicists agree that germline editing should NOT be
used for clinical reproductive purposes; the risk cannot be justified
by the potential benefit.
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21. Ethical issues about CRISPR cas9
■ This technique is dangerous because of the spread of the new
changes among humans/animals.
■ Another point to worry about is that crispring can be
performed by even a talented high scholar if he/she's
completely aware of the procedure.
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23. How can genome editing be efficient to
human in the near future
■ Could have major implications for treating non-dividing
cells in the heart and liver – and could make people live
longer.
■ To fix genes TO CURE INCURABLE DISEASES
■ Sequencing genes to spot the site of any mutation.
■ To restore the sight of rats blinded by a condition which
also affects humans.
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24. CRISPR super baby goals!
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25. Sources:
o National Academies of Sciences, E., Medicine, Human Genome Editing: Science, Ethics, and
Governance. Washington, DC: The National Academies Press. 2017.
o Fuguo Jiang and Jennifer A. Doudna, CRISPR–Cas9 Structures and Mechanisms, Annual Review
of Biophysics, May 2017
o He Jiankui, the Human Genome Editing Conference, Hong Kong, 28 November 2018
o Julia Paoli, HIV Resistant Mutation, October 06, 2013
o Molecular Cell, DOI, 14 December 2018
o Shepherd, Christian; Wong, Sue-Lin; Kelland, Kate "Chinese scientist who gene-edited babies
fired by university“; 21 January 2019.
o Keiichiro Suzuki, Yuji Tsunekawa, In vivo genome editing via CRISPR-Cas9 mediated
homology-independent targeted integration, November 16, 2016
o The new SLENDR technique: Protein labeling in the developing brain by genome editing
o Max Planck Florida Institute for Neuroscience, The new SLENDR technique: Protein labeling in
the developing brain by genome editing, May 12, 2016
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26. THANK YOU