Genetic engineering of humans

1. Genetic
Engineering of
humans
By- Sanju sah
St. Xavier’S college, Maitighar,
Kathmandu
Department of microbiology

2. INTRODUCTION
▪ Genetic engineering, sometimes called genetic modification, is the
process of altering the DNA in an organism’s genome.
▪ This may mean changing one base pair (A-T or C-G), deleting a whole
region of DNA, or introducing an additional copy of a gene.
▪ It may also mean extracting DNA from another organism’s genome
and combining it with the DNA of that individual.
▪ Genetic engineering is used by scientists to enhance or modify the
characteristics of an individual organism.
▪ Genetic engineering can be applied to any organism, from a virus to a
sheep.
▪ Genetic engineering as method of introducing new genetic elements
into organisms has been around since the 1970s.

3. ▪ Genetic modification can be applied in two very different
ways: somatic genetic modification and germ line genetic
modification.
▪ Somatic genetic modification adds, cuts, or changes the genes
in some of the cells of an existing person, typically to alleviate a
medical condition. These gene therapy techniques are
approaching clinical practice, but only for a few conditions, and
at a very high cost.
▪ Germ line genetic modification would change the genes in eggs,
sperm, or early embryos. Often referred to as “inheritable
genetic modification” or “gene editing for reproduction,” these
alterations would appear in every cell of the person who
developed from that gamete or embryo, and also in all
subsequent generations.

4. ▪ Genetic engineering has a number of useful applications,
including scientific research, agriculture and technology.
▪ In animals it has been used to develop sheep that produce a
therapeutic protein in their milk that can be used to treat cystic
fibrosis, or worms that glow in the dark to allow scientists to
learn more about diseases such as Alzheimer’s.
▪ In plants, genetic engineering has been applied to improve the
resilience, nutritional value and growth rate of crops such as
potatoes, tomatoes and rice.

5. Bio-ethical concern
New genetic technologies are exhilarating and terrifying. Society might
overcome diseases by tweaking individual genomes or selecting specific
embryos to avoid health problems. But it may also give rise to
"superhumans" who are optimized for certain characteristics (like
intelligence or looks) and exacerbate inequalities in society. Despite of
having huge amount of media attention toward the GM organisms,the
general public remains largely unaware of what a GM organism actually is
or what advantages and disadvantages the technology has to offer,
particularly with regard to the range of applications for which they can be
used.
For safety, ethical, and social reasons, there is broad agreement among
many scientists, ethicists, policymakers, and the public that germline
editing is a red line that should not be crossed. Using germline editing for
reproduction is prohibited by law in more than 40 countries and by a
binding international treaty of the Council of Europe.

6. ▪ Despite various criticism we should not deny the fact that genetic
modification bring a huge difference in the society; a new world with
designer babies. Although, the world isn’t able to accept it.
▪ I solely support genetically modified babies. It will fetch various
extraordinary creations and will offer a modern world with ample
opportunities and accountability.
Genome Editing With CRISPR-Cas9

7. 1. Creating designer babies
Genetic testing also harbors the potential for yet another scientific
strategy to be applied in the area of eugenics, or the social philosophy
of promoting the improvement of inherited human traits through
intervention.
However, in November 2018, a scientist named He Jiankui announced
he had edited the genes of twin baby girls who had subsequently been
brought to term. The twin girls that He helped create are publicly
known as Lulu and Nana. Their father is HIV-positive. The scientist
said he used CRISPR-Cas9 genome editing technology to disable a
gene called CCR5 to mimic a naturally occurring gene deletion that
appears to confer immunity against HIV. His reckless experimentation
has been nearly universally condemned. This development has
sparked new debate around human germline modification, particularly
between parties who desire to push the technology forward and those
who fear it could open the door to a new market-based form of
eugenics.

8. Fig. He Jiankui leads a team using the gene-editing
technology CRISPR in an effort to prevent disease in
newborns.
Fig. showing twin baby girl.

9. Much of what we currently know about the ramifications of genetic
self-knowledge comes from testing for diseases. Once disease genes
were identified, it became much easier to make a molecular or
cytogenetic diagnosis for many genetic conditions. as genetic research
advances, tests are continually being developed for traits and
behaviors that are not related to disease. Most of these traits and
behaviors are inherited as complex conditions, meaning that multiple
genes and environmental, behavioral, or nutritional factors may
contribute to the phenotype.
Advances in single-cell diagnostics and fertilization technology,
embryos can now be created in vitro; then, only those embryos that
are not affected by a specific genetic illness can be selected and
implanted in a woman's uterus. This process is referred to as pre
implantation genetic diagnosis.
2. Testing for Traits Unrelated to
Disease

10. 3. Building Better Athletes with Gene Doping
Over the years, the desire for better sports performance has driven many
trainers and athletes to abuse scientific research in an attempt to gain
an unjust advantage over their competitors. Historically, such efforts
have involved the use of performance-enhancing drugs that were
originally meant to treat people with disease. This practice is called
doping, and it frequently involved such substances as erythropoietin,
steroids, and growth hormones.
Today, WADA has a new hurdle to overcome—that of gene doping.
This practice is defined as the non therapeutic use of cells, genes, or
genetic elements to enhance athletic performance. Gene doping takes
advantage of cutting-edge research in gene therapy that involves the
transfer of genetic material to human cells to treat or prevent disease
.Because gene doping increases the amount of proteins and hormones
that cells normally make, testing for genetic performance enhancers
will be very difficult, and a new race is on to develop ways to detect
this form of doping.

11. Fig. Gene doping

12. 4. Among the benefits of editing designed to treat diseases is the
enhancement of gene and cellular therapies. At least nine areas would
benefit from the advances in these fields: 1) Infectiology; 2) oncology;
3) hematology; 4) hepatology; 5) neurology; 6) dermatology; 7)
ophthalmology; 8) pneumology; and 9) organ transplantation.
5. In addition to clinical applications, gene editing make it possible to
create isogenic and animal modified cell lines to be used in basic
biomedical research. Isogenic cells have a specific and standardized
genetic profile, whereas modified animals (known as “chimeras”) have
characteristics inherent to the human body. Thus, researchers have at
their disposal experimental models of control that facilitate the
generalization of empirical knowledge.

13. 6. By intervening on the DNA of living beings, gene editing can also have
macro-environmental effects. The optimization of the gene
drive mechanism (genetic induction) 6is an example of its systemic
applications. Through the gene drive mechanism, genetically modified
organisms are released into nature in order to disseminate a certain
genetic variant, prevailing over the species already present in the
environment.
7. In April 2015, Chinese researchers led by Junjiu Huang of the Sun Yat-sen
University conducted a study that was innovative, yet controversial. The
study consisted of an experiment on gene-editing human embryos to
repair mutations in the HBB gene, which is the encoder of the beta-globin
protein 1. Hemoglobin is composed of this protein, and the mutation in its
gene is related to the beta thalassemia disease.

14. 8. More recently, in August 2017, a similar experiment was published by
the journal Nature. Conducted at the Oregon Health & Science
University by scientist Hong Ma and her team, the study aimed to repair
MYBPC3 gene mutation in human embryos 3. This variation is known to
cause hypertrophic cardiomyopathy disorder, characterized by the
thickening of the cardiac musculature.
9. First Human Embryos edited in U.S.
For the first time, researchers in the United States have used gene
editing in human embryos in 2017. The team used “genetic scissors”
called CRISPR-Cas9 to target and remove a mutation associated with
hypertrophic cardiomyopathy, a common inherited heart disease, in 42
embryos. Two days after being injected with a gene-editing enzyme,
these developing human embryos were free of a disease-causing
mutation.

15. Fig. showing edited human embryos.

16. 10. The first clinical use of TALEN-based genome editing was in the
treatment of CD19+ acute lymphoblastic leukemia in an 11-month
old child in 2015. Modified donor T cells were engineered to attack
the leukemia cells, to be resistant to Alemtuzumab, and to
evade detection by the host immune system after introduction.
11. Extensive research has been done in cells and animals using
CRISPR-Cas9 to attempt to correct genetic mutations which cause
genetic diseases such as Down syndrome, spina bifida, anencephaly,
and Turner and Klinefelter syndromes.
12. In February 2019, medical scientists working with Sangamo
Therapeutics, headquartered in Richmond, California, announced
the first ever "in body" human gene editing therapy to permanently
alter DNA - in a patient with Hunter Syndrome.[59] Clinical trials by
Sangamo involving gene editing using Zinc Finger Nuclease (ZFN)
are ongoing.

17. 13. Researchers have used CRISPR-Cas9 gene drives to modify genes
associated with sterility in A. gambiae, the vector for malaria.[61] This
technique has further implications in eradicating other vector borne
diseases such as yellow fever, dengue, and Zika.
14. The CRISPR-Cas9 system can be programmed to modulate the
population of any bacterial species by targeting clinical genotypes or
epidemiological isolates. It can selectively enable the beneficial
bacterial species over the harmful ones by eliminating pathogen,
which gives it an advantage over broad-spectrum antibiotics.
Antiviral applications for therapies targeting human viruses such as
HIV, herpes, and hepatitis B virus are under research. CRISPR can be
used to target the virus or the host to disrupt genes encoding the virus
cell-surface receptor proteins.

18. Fig. Showing gene editing.

19. Conclusion
"Playing God" has become a strong argument against genetic engineering.
Several issues have also been raised as regards the acceptance of this
technology. These concerns range from ethical issues to lack of
knowledge on the effects genetic engineering may have. Despite all of
these current concerns, the potential for genetic engineering is
tremendous.
In the near future the new CRISPR system will also be able to eradicate
diseases and conditions that humans are predisposed for. With this new
technology scientists will be able to take the genes of a human sperm
cell and egg, and replace the genes that activate cancer or other
abnormal or unwanted defects. This will take the stress off of parents
worrying about having a child and them not being able to live it like a
normal child should. After just one generation of this process, the entire
future of the human race would never have to worry about the problems
of deformities or predisposed conditions.

20. ARE SCIENTIST TO BE
TRUSTED?

21. THANK YOU