Question
By which technique are the gene defects identified in a child or fetus treated? Explain with example.
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Answer
Gene therapy is used to correct gene defects identified in a child or fetus. In this, genes are introduced into the cells or tissues of a person to treat the disease. To treat cells with genetic defects, normal genes are transferred to the person or embryo, which compensate for the dysfunctional gene and perform its functions.
Gene therapy was first used in 1990 to overcome adenosine deaminase (ADA) deficiency in a four-year-old girl. This enzyme is essential for the functioning of the immune system. This deficiency occurs because the gene responsible for adenosine deaminase disappears. In gene therapy, first of all lymphocytes are extracted from the patient's blood and cultured outside the body. The cDNA of activated ADA is introduced into the lymphocyte (using a post-viral vector) and ultimately returned to the patient's body. These cells are usually dead, hence the genetically engineered lymphocytes need to be removed from the patient's body from time to time. If good genes isolated from bone marrow cells - produced from early embryonic cells - are introduced into ADA, then this could be a permanent treatment.
Gene therapy was first used in 1990 to overcome adenosine deaminase (ADA) deficiency in a four-year-old girl. This enzyme is essential for the functioning of the immune system. This deficiency occurs because the gene responsible for adenosine deaminase disappears. In gene therapy, first of all lymphocytes are extracted from the patient's blood and cultured outside the body. The cDNA of activated ADA is introduced into the lymphocyte (using a post-viral vector) and ultimately returned to the patient's body. These cells are usually dead, hence the genetically engineered lymphocytes need to be removed from the patient's body from time to time. If good genes isolated from bone marrow cells - produced from early embryonic cells - are introduced into ADA, then this could be a permanent treatment.
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