Gene therapy - class-XII

Adenosine deaminase deficiency SCID, commonly called ADA SCID, is a very rare genetic disorder. It is caused by a mutation in the gene that encodes a protein called adenosine deaminase (ADA). 

Adenoviruses are commonly used as viral vectors in gene therapy because they can efficiently deliver genetic material into host cells.

An antiviral drug is used to treat genital herpes outbreaks stay symptom-free longer. These drugs can also reduce the severity and duration of symptoms when they do flare up. Drug therapy is not a cure, but it can make living with the condition easier. Because of lack of research about the Herpes virus action mechanism, there is no cure for Herpes but it is inhibited by acyclovir. It is one of the most common sexually transmitted infections. 

Retroviruses are frequently used as vectors in gene therapy, particularly for SCID (Severe Combined Immunodeficiency), because they can integrate their genetic material into the host genome.

The correct option is C

The first successful gene therapy trial in 1990 (often cited as 1992 in some texts) was performed on Ashanthi DeSilva for Adenosine Deaminase (ADA) deficiency.

Permanent cure for ADA deficiency involves introducing functional ADA genes into bone marrow stem cells at an early stage, allowing the body to produce its own functional enzyme.

Gene therapy is the medical field focused on treating or preventing diseases by modifying the genetic material within a patient's cells.

Gene therapy can theoretically be applied to patients of any age, although the type of therapy (somatic vs germline) and the specific condition dictate the feasibility and ethical considerations.

Statement (b) is incorrect because cry genes are used against insects/pests, not nematodes. Statement (d) regarding injustice and benefit-sharing is related to biopiracy and ethical issues in biotechnology, not specifically molecular diagnosis.

Adenosine deaminase (ADA) deficiency can be treated by bone marrow transplantation, or by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But permanent treatment can be done by introduction of gene isolated from bone marrow cells, which produces ADA, into the cells of the patient at early embryonic stage.

Gene therapy is a collection of methods that allow correction of a gene defect that has been diagnosed in a child/embryo. In this method, genes are inserted into a person's cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.

Tissue Plasminogen Activator (TPA) is used in medical treatments to break down blood clots (thrombolysis).

The fundamental principle of gene therapy is to replace a defective or missing gene with a functional copy to restore normal cellular function.

The first clinical gene therapy was given in 1990 to a 4-years old girl with adenosine deaminase (ADA) deficiency. This enzymes is very important for the immune system to function. ADA deficiency can lead to severe combined immune deficiency (SCID). 

Severe Combined Immunodeficiency is a primary immune deficiency characterized by the severe defects in both the T- and B-lymphocyte systems. This usually results in the onset of one or more serious infections within the first few months of life. These infections are usually serious and may even be life-threatening, they may include pneumonia, meningitis or bloodstream infections. There are several forms of SCID. The most common type is linked to the X-chromosome, making this form affect only males. Other forms of SCID usually follow an autosomal recessive inheritance pattern or are the result of spontaneous mutations. One of these other forms is linked to a deficiency of the enzyme adenosine deaminase (ADA) while other cases of SCID are caused by a variety of other defects.

Retroviruses are a class of enveloped viruses that contain a single-stranded RNA genome. They are able to efficiently integrate permanently into the human genome after entering cells, where they provide the basis for permanent expression of foreign DNA. They offer several benefits like the integration of the gene of interest into chromosomes, stable expression, reducing a lot of unnecessary steps required when we go by gene therapy by other methods and the unique life cycle of the virus causing no immunogenicity.

Adenosine deaminase (ADA) deficiency can be treated by bone marrow transplantation, or by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But permanent treatment can be done by introduction of gene isolated from bone marrow cells, which produces ADA, into the cells of the patient at early embryonic stage.

Gene therapy is a collection of methods that allows correction of gene defect that has been diagnosed in a child  for adenosine deaor embryo. An example of gene therapy is the introduction  of geneminase in persons suffering from ADA deficiency, a disorder caused due to the deletion of gene for adenosine deaminase. In some patients , it can be cured by bone marrow transplantation whereas in some by the enzyme replacement therapy

Gene therapy is a collection of methods, that allows correction of gene defect that has been diagnosed in a child/embryo. Correcting of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.

Gene therapy is a newly emerging branch of biotechnology with tremendous results. It is basically used for correcting genetic disorders. In gene therapy, normal genes are introduced in the cells to replace the missing genes or defective genes. 

Gene therapy is a collection of methods, that allows correction of a gene defect that has been diagnosed in a child embryo.

First successful gene transfer in human was performed by F.Anderson. Ashi Disilva a 4-year girl was treated by replacing ADA gene in lymphocytes.

Gene cloning is the process of making the copies of gene of interest by locating it in DNA followed by extraction of DNA containing that gene. A probe is a radiolabeled single-stranded DNA/ RNA fragment used to search for a gene of interest or other DNA sequence. For the purpose, the base sequence of probe is complementary to the target sequence to facilitate its base pairing with target gene. Gene multiplication is a mechanism that increase the genes in their number of copies. It is also called as gene amplification and is the source of evolution. Gene therapy is the process of introduction of DNA into living human beings in order to treat disease. It is used to replace a missing gene product or to correct mutant alleles. Correct answer is C.

Gene therapy is defined as the therapeutic delivery of nucleic acid into a patient's cells as a drug to treat disease by replacing or supplementing a defective gene.

• Insulin-Dependent Diabetes Mellitus or IDDM is an immune deficiency disorder. It occurs due to a mutation in a gene involved in insulin-producing β cells in the pancreas. 
• Hashimoto's disease is an autoimmune disorder that results in hypothyroidism. It results in defects in the maturation of T lymphocytes. 
• Severe combined immunodeficiency (SCID) is an immunodeficiency syndrome. It occurs due to a mutation in the gene involved in the maturation of T and B lymphocytes. 
• Pernicious anemia is also called as vitamin B$ _{12}$ deficiency syndrome. It results due to a lack of intrinsic factor. 

Introduction of a normal functional gene into cells, in order to replace defective or mutated gene is known as gene therapy. It is also called as gene transfer. It is done to correct genetic disorders. Biosafety is the prevention of large-scale loss of biological integrity. Biopiracy is the practice of exploiting indigenous knowledge of nature, originating with indigenous peoples without compensation to the indigenous people. Biopatent is a patent granted by the government to the inventor of biological entities.

DNase (Deoxyribonuclease) is used in cystic fibrosis treatment to break down the thick mucus in the lungs, which is rich in DNA from dead white blood cells. While gene therapy is a research area for cystic fibrosis, DNase is the standard pharmacological treatment listed.