Question

How might viruses help to cure genetic diseases?

Answer 1

Viruses are always known to cause diseases. Viruses can either kill the host cell or can transform the host cell for its purpose. But sometimes viruses are used for different purposes. They are used as a vector called a carrier to deliver the absent gene.

Complete answer:
Whenever gene therapy is given to a patient and viruses are used as vectors then that gene therapy is called Virotherapy. Or we can say, any treatment of a disease by using a virus is called Virotherapy. Viruses are manipulated and reprogrammed by using biotechnology. Viruses are used for such therapy because they can take over the host cell mechanisms for their own purpose.
Viruses are used as a vehicle to transmit DNA or RNA to the host cell’s genetic material and cause pathogenicity. This genetic material is transformed for a specific function. The viruses are modified so they can't cause disease when used in people.
For example to compensate any enzyme that is congenitally absent can be treated by this.
Although helpful Virotherapy has some disadvantages-
-Exaggerated immune response - the body detects this virus as a foreign particle and initiates the immune response. Sometimes the body's immune response is so exaggerated that it can lead to severe inflammation and sometimes even organ failure can take place.
-Viruses are highly mutagenic - viruses can regain their original abilities to cause disease due to mutation.
-Possibility to cause tumor - some viruses such as Epstein Barr virus if used as a vector can cause cervical cancer.

Note: There are some vectors that can be used in place of viruses -
-Stem cells: Stem cells are those cells which were created during embryonic development and form various tissues in our body. They can be made to make certain cells or certain enzymes. for example in the deficiency of Adenosine deaminase deficiency (ADA) that causes severe combined immunodeficiency (SCID). Also called ADA-SCID. In this condition the immune system is so weak that the body can not fight with any kind of infection.
-Liposome: They can carry genetic materials to the DNA.