Question

What is gene therapy? Mention two types of gene therapy.

Answer 1

Hint: Genes are the units of inheritance. We can alter the genetic material which is present inside the nucleus of a cell. In this manner, we can get rid of the characters which lead to certain diseases.

Step by step answer:The genes contain information that is needed to express certain characters in an organism. The genes are present in the DNA which is located inside the nucleus of the cell. Today we have developed technologies that help us to treat diseases by a process called gene therapy. In gene therapy, the gene defects are corrected in the embryonic stage itself. By this, we can replace the defective gene with a normal gene. If we do gene therapy in the early embryonic stage we can cure certain diseases that cannot be treated by ordinary treatment. The first gene therapy was done on a girl with adenosine deaminase or ADA deficiency. In this technique, lymphocytes are grown in cell culture and a normal gene is inserted into them. By the periodic infusion of these lymphocytes, the disease was controlled. Remember that these diseases are not completely curable until we do it in embryonic stages. Many hereditary diseases like sickle cell anemia, haemophilia, Parkinson’s disease, etc are treated by gene therapy. Gene therapy is of two types. They are somatic gene therapy and germline gene therapy. In somatic gene therapy, we transfer a gene into an ordinary cell of the body. But in germline gene therapy we introduce a gene to a germ cell.

Note: In order to deliver a gene to the desired cell, a transporting vehicle is needed. It is called a vector. As certain viruses deliver genes to the cells, they are used as vectors. But note that today vector less gene transfer is also possible.