This document is a biology investigatory project report on gene therapy submitted by Mr. Lokesh Ranjan Mahanta for the CBSE curriculum, guided by Mr. Aman Rathod. It covers the definition, history, types, vectors, methods of gene delivery, success cases, problems, ethical issues, and a conclusion emphasizing the potential of gene therapy despite its complexities and current high costs. The report includes a certificate, acknowledgment, and bibliography.

1. VIDYALAYA,
TIKIRA, GHATAGAON, KEONJHAR - 758029
SESSION 2022-23
BIOLOGY INVESTIGATORY
PROJECT REPORT
TOPIC :- GENE THERAPY
SUBMITTED BY :-
Mr. LOKESH RANJAN MAHANTA
CLASS : XII-SCIENCE
SECTION : ‘B’
SCHOOL ROLL NO. : 09
CBSE ROLL NO. :
SUBMITTED TO :-
Mr. AMAN RATHOD
(PGT Biology)
SUBJECT : BIOLOGY

2. CERTIFICATE
This is to certify that this Biology Investigatory Project on the topic
‘GENE THERAPY’
has been successfully completed by
MR. LOKESH RANJAN MAHANTA
of class XII(B) under the guidance of
MR. AMAN RATHOD
for the fulfillment of the curriculum of the Central Board of Secondary
Education (CBSE) leading to 12th Board examination of session 2022-23.
i
Teacher In-charge External Examiner Principal
Date : / /

3. ACKNOWLEDGMENT
In the accomplishment of this project successfully, I would like to
express my gratitude and appreciation to all those who gave me the
possibility to complete this.
Primarily I would thank God for being able to complete this
project with success. Then I would like to thank our Biology teacher
Mr. Aman Rathod whose valuable guidance and pieces of advice
have been the ones that helped me patch this project and make it a
full-proof success. I would also like to thank our Principal Mr.
Suvendu Kumar Moharaj for his suggestions and his instructions
that served as the major contributor towards the completion of the
project.
Finally, I would like to thank my parents for helping me
economically and my classmates who have helped me with their
valuable suggestions that have been helpful in various phases of the
completion of the project.
ii

4. DECLARATION
I hereby declare that the investigatory project report
entitled ‘GENE THERAPY’ submitted to Odisha Adarsha
Vidyalaya, Tikira, is a record of an original work done by me
under the guidance of Mr. Aman Rathod, PGT Biology,
Odisha Adarsha Vidyalaya, Tikira, and this project report is
submitted for the partial fulfillment in particular fulfillment of
curriculum of Central Board of Secondary Education (CBSE)
leading to the 12th Board examination of session 2022-23. This
project report is not submitted to any other educational institute
or for any other purpose.
iii
CLASS : XII(B)

5. CONTENTS
1. Certificate ……………..……………………………………….. i
2.Acknowledgement ………………………………………….. ii
3.Declaration ……………………………………………………. iii
4.Introduction …………………………………………………..... 2
5. Brief history of Gene Therapy …………………………… 4
6. Types of Gene Therapy ……………………………….......... 5
7. Vectors of Gene Therapy …………………………………. 13
8.Methods of Gene Delivery ………………………………… 20
9. Success cases of Gene Therapy …………………………. 22
10.Problems with Gene Therapy ………………………….. 23
11.Ethical issues ……………………………………………......... 24
12.Conclusion ………………………………………………….… 25
13.Bibliography ……………………………………………......... 26

7. INTRODUCTION
WHAT IS A GENE ?
A gene is a basic unit of heredity.
It is located in chromosomes.
It encodes protein formation.
Replication
Transcription
Translation
Protein
DNA RNA
Reverse transcription
Proteins formed to carry out
various functions.
If gene dysfunctions, it causes
altered protein formation.
When there is a mutation in the
gene, then the wrong codon will
code for the wrong amino acid in the
protein which leads to an alteration
in the basic structure of the protein.
2

8. WHAT IS GENE THERAPY?
Gene therapy is a medical approach
that treats or prevents diseases by
correcting the underlying genetic
problem.
These techniques allow doctors to
treat a disorder by altering a
person’s genetic makeup instead of
using drugs or surgery.
There are four approaches:-
1) A normal gene is inserted to compensate for the dysfunctional gene.
2)An abnormal gene is traded for a normal gene. 3
3)An abnormal gene is repaired through selective reverse mutation.
4)Change the regulation of gene pair.

9. BRIEF HISTORY OF GENE THERAPY
US Office of
The National
Technology
Institute of Health
(NIH) took lead in
recombinant DNA
(rDNA) research
regulation.
Jesse Gelsinger
becomes the
first fatality in
gene therapy.
Assessment
stressed the
difference 637 GT clinical
trials (3464
patients)
between somatic
and germ-line
therapy.
1974 1999 2005
1984
2003
1967 1990
1980
4
Nobelist
Marshall
Nirenberg
wrote for
programming
cells.
The National
Institute of
Health (NIH)
performed
the first
approved
gene therapy
procedure.
FDA placed a
temporary halt
on all gene
Dr. Martin J.
Cline performs
the first DNA
transfer into
bone marrow
cells.
therapy trials
using retroviral
vectors in
blood stem
cells.

10. TYPES OF GENE THERAPY
Gene therapy is classified into two types:-
1) Somatic Gene Therapy
2) Germ-line Gene Therapy
1) SOMATIC GENE THERAPY
In somatic gene therapy, the desired
therapeutic gene is transferred to
somatic cells or stem cells of the
human body.
The gene is not transferred to the
offspring.
This is related to a single person and
the only person who has the
damaged cell will be replaced with
healthy cells.
5
This technique is considered the
best and safest method of gene
therapy.
Mechanism of Somatic gene therapy

11. 2) GERM-LINE GENE THERAPY
In germ-line gene therapy, the
desired therapeutic gene is
introduced in the germ cells
(eggs or sperms) of the human
body.
The gene gets transferred from
one generation to another
generation.
This method is generally adopted
to treat the genetic, disease
causing-variations of genes that
are passed from the parents to
their children.
This therapy is not legal in many 6
Mechanism of Germ-line gene therapy
places as the risk outweigh the
rewards.

12. DIFFERENCES BETWEEN SOMATIC GENE
THERAPY AND GERM-LINE GENE THERAPY
In somatic gene therapy,
In germ-line gene therapy,
unhealthy cells are modified
concerned genes are
with the correct gene and
transferred into gametic or
then transferred into the
early embryonic cells.
patient’s body.
Cannot be inherited by
future generations.
Effective in target cells
only.
Effective in all cells.
Carried out multiple times
as it does not last for long.
Can be carried out once for
long lasting effects.
For safety, ethical and
technical reasons, it is not
being attempted at present.
7
E.g., Introduction of genes
into bone marrow cells,
blood cells, skin cells etc.
E.g., Genes introduced into
eggs and sperms.

13. TYPES OF SOMATIC GENE THERAPY
SOMATIC GENE THERAPY
EX VIVO IN VIVO
Ex vivo gene therapy refers to
the process of removing specific
cells from a person, genetically
altering them in a laboratory,
and then transplanting them
back into the person.
In vivo gene therapy refers to
the direct delivery of genetic
material either intravenously
(through an IV) or locally to a
specific organ (e.g., directly into
the organ).
It works through the help of a
vector, which directly inserts
functional copies of a gene into
target cells to treat a mutated
or missing gene.
This technique has been proven
in many areas of research.
Some of the currently approved
gene therapies deliver genetic
material in vivo.
works by genetically
modifying a patient’s stem cells,
which then replace target cells
that or
malfunctioning gene.
This technique is used to treat
blood and immunological
have a missing
8
diseases as well as genetic
diseases that affect tissues and
organs that can be reached by
blood cells.

14. EX VIVO GENE THERAPY
Procedure for ex vivo gene therapy is as follows:-
Isolate cells with genetic defect
from a patient.
1
2
3 Introduce the therapeutic genes.
4
5
Select genetically corrected cells
and grow them. 9
Transplant the modified cells to
the patient.

15. EX VIVO GENE THERAPY
Example:-
ADA (Adenosine deaminase) Deficiency
1st gene therapy(1990) – to correct the deficiency of
the enzyme, Adenosine deaminase (ADA).
It was performed on a 4-year-old girl Ashanthi
DeSilva.
She was suffering from SCID (Severe Combined
Immunodeficiency).
SCID Ashanti DeSilva
Caused due to a defect in the
gene coding for ADA.
Deoxyadenosine accumulates
and destroys T-lymphocytes.
Disrupts immunity,
suffer
thus
from
patients
infectious diseases and die at
a young age.
10
Procedure to treat ADA deficiency

16. IN VIVO GENE THERAPY
Procedure for ex vivo gene therapy is as follows:-
Therapeutic genes are inserted
in the vectors.
1
Genetically altered DNA is
injected into the patient’s body.
2
DNA is incorporated into the
target cells.
3
4
11
Proteins encoded by the inserted
genes are produced.

17. IN VIVO GENE THERAPY
Example:-
Cystic Fibrosis
Cystic fibrosis is a progressive,
genetic disease that causes
persistent lung infections and
limits the ability to breathe over
time.
In patients with cystic fibrosis, a
protein called Cystic Fibrosis
Transmembrane Regulator (CFTR)
is absent due to a gene defect.
In the absence of CFTR, chloride
ions concentrate within the cells
and draws water from the
surrounding.
This lead to the accumulation of
sticky mucous in the respiratory
tract and lungs.
12
Treated by in vivo replacement of
defective gene by adenovirus
vector.
Gene therapy for Cystic fibrosis

18. VECTORS IN GENE THERAPY
To transfer the desired gene into the target cell, a carrier or vehicle
is required. Such vehicles of gene delivery are known as ‘VECTORS’.
There are two main classes of vectors. Those are:-
1) Viral vectors
2) Non-viral vectors
13
Viral vectors Non-viral vectors

19. IDEAL VECTORS
An ideal vector must have the following
features:-
Target the right cells.
Small size and low molecular weight.
Integrate the gene in the cells.
Activate the gene.
Avoid harmful side effects
In the real world, no universal vector exists.
1) VIRAL VECTORS
Viruses introduce their genetic material into
the host cell as part of their replication cycle.
These are used as vectors by removing their
viral DNA and inserting the therapeutic DNA
in them.
14
The viruses used are altered to make them
safe, although some risks still exist with this
technique of gene therapy.

20. TYPES OF VIRAL VECTOR
A number of viruses have been used for human gene therapy including :
1) Retrovirus
2) Adenovirus
3) Adeno-associated virus
4) Herpes simplex virus
1) RETROVIRUS
The recombinant retroviruses have the ability to
integrate into the host genome.
The typical maximum length of an allowable DNA
insert in a retroviral vector is about 8-10 kB.
Target – actively dividing cell.
Retrovirus
15
Action of Retrovirus

21. a) LENTIVIRUS
Subclass of retroviruses.
The viral genome in the form of RNA is reverse-
transcribed when the virus enters the cell to produce
DNA, which is then inserted into the genome at a random
position via the viral integrase enzyme.
Target – dividing, non-dividing cells Lentivirus
2) ADENOVIRUS
Adenoviral DNA does not integrate into the genome and
is not replicated during cell division.
Humans commonly come in contact with adenovirus. The
majority of patients have already developed neutralizing
antibodies which can inactivate the virus.
Target – dividing, non-dividing cells
3) ADENO-ASSOCIATED VIRUS Adenovirus
It is a small virus and it affects humans and other primates.
It enters the host cell, becomes double-stranded, and gets
integrated into chromosomes.
16
It is not currently known to cause disease and consequently
the virus causes a very mild immune response.
Target – non-dividing, dividing cells
Adeno- associated virus

22. 4) HERPES SIMPLEX VIRUS
The herpes simplex virus is a human neurotropic
virus.
This is mostly examined for gene transfer in the
nervous system.
These viruses have a natural tendency to infect a
particular type of cell. Herpes simplex virus
ADVANTAGES AND DISADVANTAGES OF USING VIRAL VECTORS
They can cause immune
amount of genetic
materials. Therefore some
genes may be too big to fit
into some viruses.
17
DISADVANTAGES

23. 2) NON- VIRAL VECTORS SYSTEM
1) PURE DNA EXTRACT
Direct introduction of pure DNA
construct into the target tissue.
Efficiency of DNA uptake by cells and
expression is rather low.
Consequently, large quantities of DNA
have to be injected periodically.
Pure DNA extract
2) DNA MOLECULAR CONJUGATES
Commonly used synthetic conjugate is
poly-L-lysine bound to specific target
cell receptors.
Therapeutic DNA is then made to
combine with the conjugate to form a
complex.
18
It avoids the lysosomal breakdown of
DNA.
Poly-L-lysine

24. 3) LIPOPLEXES
Lipid DNA complexes.
DNA construct surrounded by artificial lipid
layer.
Most of it gets degraded by lysosomes.
4) HUMAN ARTIFICIAL CHROMOSOME
Can carry a large DNA i.e., with one or
more therapeutic genes.
ADVANTAGES AND DISADVANTAGES OF USING NON-VIRAL VECTORS
ADVANTAGES
Easy to produce
Good transduction of some
cell types
19
There is no limit to the
transgene size
Useful for local therapy
DISADVANTAGES

25. METHODS OF GENE DELIVERY
1) PHYSICAL METHODS
i) GENE GUN/ BIOLISTICS
It uses a gun-like instrument to send
desired genes inside host cells.
It introduces the desired rDNA into a
plant cell by coating it with gold or
tungsten and firing it into the tissue at
high velocity.
ii) MICROINJECTION Gene gun Mechanism of gene gun
In this method, the host cells are forced to
take up the desired rDNA molecules using
microinjection.
This is a physical method that requires the
usage of a specialized optical microscope.
The host cell is selected, and the rDNA is
injected into the host cell.
20
This method is generally used to introduce
rDNA into animal cells. Microinjection

26. 2) CHEMICAL METHODS
i) USING DETERGENT MIXTURE
Certain charged chemical compounds
like calcium phosphates are mixed with
functional cDNA of the desired
function.
The mixture is introduced near the
vicinity of recipient cells.
The chemicals disturb the cell
membrane, widen the pore size, and
allow cDNA to pass through the cells.
Gene transfer using detergent mixture
ii) LIPOFECTION
It is a technique used to inject genetic
materials into a cell using
transfection agents like liposomes.
Liposomes are artificial phospholipid
vesicles used to deliver a variety of
molecules including DNA into the
cells.
21
Mechanism of lipofection

27. SUCCESS CASES OF GENE THERAPY
1) SICKLE CELL ANEMIA
It is a genetic condition that affects the
RBCs.
It affects the hemoglobin in the blood
and causes RBCs to be rigid and shaped
like the letter ‘C’ or a sickle
Until recently, a bone marrow transplant
is the only cure for sickle cell anemia.
Gene therapy for Sickle cell anemia
2) PARKINSON DISEASE
It is a long-term degenerative disorder of the
central nervous system that mainly affects
the motor system.
Gene therapy in Parkinson’s disease consists
of the creation of new cells that produce a 22
specific neurotransmitter (dopamine),
protect the neural system, or modification of
genes that are related to the disease.
Gene therapy for Parkinson disease

28. PROBLEMS WITH GENE THERAPY
SHORT-LIVED NATURE OF GENE THERAPY:
Patients will have to undergo multiple rounds of gene therapy.
1
IMMUNE RESPONSE:
Stimulates the immune system that reduces gene therapy 2
effectiveness.
PROBLEMS WITH VIRAL VECTORS:
Potential problems to the patient like toxicity, immune and
inflammatory responses, and gene control targeting are created.
3
23
MULTI GENE DISORDER :
Disorders like heart disease, high blood pressure, arthritis, and 4
diabetes are caused by the combined effect of many genes.

29. ETHICAL ISSUES OF GENE THERAPY
Is it all right to use
the therapy in the
prenatal stage of
development in
babies?
What is normal
and what is the
disability or
disorder and who
decides?
Should people be
allowed to use gene
therapy to enhance
basic human traits such
as height, intelligence,
etc.? 5
1
3 Preliminary attempts at
Who will have
access to your
genetic
gene therapy are
expensive. Who will have
access to these therapies?
Who will pay for their use?
Is it interfering
with God’s plan?
information?
24
2 4
6

30. CONCLUSION
Theoretically, gene therapy is the permanent solution
for genetic diseases. But some treatments are short-
lived and have to be repeated.
1
g
2
I
But it has several complexities. At its current stage, it
is not accessible to most people due to its huge cost.
3 A breakthrough may come at any time, and a day may come
when almost every disease will have gene therapy.
4
Gene therapy has the potential to revolutionize the
practice of medicine.
25

31. BIBLIOGRAPHY
NCERT Biology Book – XII
www.youtube.com
www.googleimages.com
http://en.wikipedia.org/wiki/Gene_therapy
http://en.wikipedia.org/wiki/Somatic_gene_therapy
http://en.wikipedia.org/wiki/Germ_line_gene_therapy
http://www.medindia.net/articles/genetherapy_treatment.htm
www.byjus.com
And more…
26

32. THANK YOU!