From the inception and evolution of mankind we have been able to make groundbreaking progress in the field of medicine but still some inborn genetic diseases like cystic fibrosis, hemophilia and familial hypercholesterolemia had no proper cure till a few decades ago. The field of Recombinant DNA technology opened a new world of possibilities.
b. Rationale of the study; Why is this study important?
Genes are a section of DNA which determine almost everything about our body. They determine things from our appearance , survival , health and behavior . Any malfunctioning or bad genes inherited or mutated can cause life hampering illness Using Recombinant DNA technology most recent and powerful tool CRISPR which has revolutionized and making gene editing possible and most importantly affordable and carried out in a simpler way treatment of these diseases by altering the disease causing gene sequence has been made possible.
c. Results & Conclusion of the research
Gene therapy is the referred to the process of introducing genes into existing target cells to prevent or cure a variety of diseases .For achieving the goal of delivering these genes effectively is accomplished by 2 methods:
i. Gene Delivery Vectors: For purpose of gene cloning at scale nothing is better than
viruses since they have machinery to replicate exponentially and deliver to cells .
Retroviral vectors are made by converting RNA genome to DNA in infected cell so they
are able to integrate host genome . By manipulating the viral genome viral
ii. CRISPR: In 1987 while investigating a particular gene in e coli scientists noticed a pattern in DNA surrounding it 5 identical sequences each composed of 29 bases separated from each other by 32 base block of DNA called spacers with unique sequence These repeating patterns were found in many different microbes and was coined the term Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR).
iii. They were found next to enzyme producing genes known as CRISPR Associated Genes (Cas Genes) which can cut DNA .
iv. Later found that these were a technique used by Bacteria to protect against viral invasions by saving part
of viral DNA in CRISPR sequence and spacers contains history of all infection. Upon attack of
virus again CRISPR sequence is transcribed in crRNA molecules which binds with
matching viral DNA which is then cut out by CAS9 enzyme.
v. Later it figured that CRISPR /CAS9 system is programable and can be used for gene
editing by synthesizing guide RNA molecule which match the sequence of the gene
which needs to be edited then the CAS9 enzyme cuts the matching DNA sequence on
both ends .
vi. In 2015 it was used to cut HIV virus out of living cells in lab and later on rats infected
with HIV were successfully treated .
vii. In 2019 a patient named Victoria Gray suffering from sickle cell disease caused due to
sickle shaped deformed hemoglobin was the first patient cured using CRISPR editing
Using CRISPR is a new breakthrough achievement which can provide a better life to
many others like Victoria Gray who suffer from these life threatening diseases as in US alone there
are 100,000 people who suffer from this disease as it can be inherited.