Gene therapy definition

Gene therapy is a medical process that is used to prevent diseases by treating the genes of a person. Some conditions can be cured by altering or adding genes to a person’s body. It is limited to some cases only, but doctors may allow genes over drugs or surgery, if successful in the future. Researchers are working towards attaining such successes and looking for several approaches, including the following: 

• Introducing a new gene to the body to help fight against diseases
• Replacing an existing gene responsible for a particular illness or disease with a healthy copy of the same gene
• Deactivating an existing gene that is not functioning correctly

Although gene therapy is an effective solution for inherited disorders, with regard to some categories of cancer and viral infections, it is still considered a risky treatment. It is still under study as researchers try to ascertain whether it is safe or not. Doctors believe gene therapy is only for those diseases that don’t have any cure.

Working of gene therapy 

According to researchers, there are several ways in which gene therapy works such as:

• Introducing a new gene to the body to help fight against diseases
• Replacing an existing gene responsible for a particular illness or disease with a healthy copy of the same gene
• Deactivating an existing gene that is not functioning correctly

Gene therapy is used

• To put genetic materials into cells to replace non-functioning genes
• To make beneficial proteins
• To destroy problem causing genes and a new gene is introduced in place of the defective gene

Vector or Carrier

A gene  that is directly inserted into a cell may not function properly. Therefore, a carrier (known as vector) is genetically modified to deliver the gene is needed. 

• Viruses are used as carrier to deliver the new gene by infecting the cell. They do it by infecting the cell. These vectors are modified in such a way that they cannot cause problems such as disease when used in people 
• Certain types of viruses, like retroviruses, combine their genes with the new genes into a chromosome present in a human cell. Other viruses, such as adenoviruses, combine their DNA with the cell’s nucleus
• The vector can be put directly into a particular tissue of the body, where it can be taken by the cells. On the other hand, a sample of the patient’s cells can be taken out and exposed to the vector in a lab.  Then the vector is mixed with cells. If this treatment is a success, it gives rise to a new functional protein

There are some challenges while operating gene therapy, but researchers have overcome these. There are still some things that need to be worked out. For example, scientists must find less complicated and better ways to introduce genes and target specific cells. They must ensure that the body accurately controls new genes.

Gene therapy classification

Gene therapy can be categorised into the following. Read about them for more clarification.

Somatic Gene Therapy

This usually occurs in the somatic cells of the human body. This can happen only when someone’s damaged cells need to be replaced. In this category, therapeutic genes are transferred to the somatic cells or the human body’s stem cells. Somatic gene therapy is considered to be a safe method. 

Germline Gene Therapy

It occurs in the germline cells of the human body. This method is used to treat disease-causing variations of genes that are usually passed from parents to their children. 

Applications of gene therapy

The applications of gene therapy are mentioned below- 

1. It is used in the replacement of genes that are responsible for diseases.
2. Gene therapy is used to treat diseases such as cancer, ADA deficiency, cystic fibrosis, etc.
3. This method is effective in destroying problem causing genes.  
4. Adding genes can help the body to fight against genes. 

Challenges of gene therapy

Gene therapy comes with some risks that are discussed below. As we know, a gene requires a carrier when getting injected into the body. This is called a vector. Most viruses are used as vectors. Below are the risks associated with gene therapy:

• Unwanted immune system reaction. Your immune system may not recognise the new element inserted into your body. It may cause inflammation or organ failure in some cases
• Possibility of causing a tumour. While inserting new genes, if they get inserted at the wrong place, it can cause tumours
• Targeting the wrong cells. It is possible that viruses may alter more than one type of cell. During this process, healthy cells may be damaged and lead to illness
• Infection caused by the virus. It is possible that once the virus is introduced, it may recover its original ability to cause diseases

Conclusion

Gene therapy is nothing but the addition of new or modified genes into the body with the help of viruses. This is used to treat some diseases such as cancer and inherited disorders. There are many ways in which a gene is introduced to the body. We have discussed it in detail above. While performing gene therapy, some complications need to be taken care of. Researchers are trying to find some ways so that many diseases can be cured by gene therapy.