Genetic Disorders: The Pros And Cons Of Gene Therapy

As diseases claim the lives of increasing numbers of people, scientists have worked hard to develope new methods of treatment; a dominant approach to this that has attracted a great deal of attention is gene therapy. Gene therapy is the method of replacing defective genes or inserting new genes as an effort to cure disease or enhance the body’s potential to fight harmful intruders (Lyford J.). Genes consist of DNA, which are fundamental codes found in every organism. These codes are responsible for directing cells in performing the correct function and regulating body systems, if any of these were to fail, illness would occur (Mayo Clinic Staff.). Gene therapy is a technique used to modify or deactivate defective genes; it has the potential

The crucial discovery of James Watson and Francis Crick's DNA structure created a base for researchers to develop the basics of molecular gene therapy, allowing them to improve existing methods of isolating genes in DNA (Bergeson.). With these modified techniques of DNA recombination, the idea of correcting gene defects or replacing genes to cure disease in patients emerged. Researchers conducted several experiments staging the efficiency of retroviral vectors, a means of gene transport, displaying successful phenotype correction. Results of these experiments showed that modified genes inserted into the “wrong” gene can create a functioning protein (Friedmann Theodore.). The first approved gene therapy procedure was performed on a four year old girl on September 14th, 1990. The patient was born with a genetic disease called Severe Combined Immunodeficiency (SCID), which drastically impaired her immune system. Children with SCID rarely make it to adulthood as their weakened immune systems cannot handle the most mild of infections. In response to this case, doctors removed white blood cells from the

Viruses are the ideal mechanism for gene transfers because of their capability of injecting their own genetic material into a patient's genome as a means of reproduction (Lyford J.). Before doctors can begin the procedure, they must be able to identify the specific gene on a chromosome that is responsible for causing the disorder; they verify this through genetic testing. In genetic testing, a strand of DNA with restriction enzymes is cut and inserted into plasmid. It is then analyzed to locate the gene. After this process is completed scientists are able to begin strategizing their plans for gene therapy (Bergeson.). First, a vector, a vehicle used to introduce a corrected gene into a cell, is found. Patients with Wiskott - Aldrich Syndrome (WAS) use a form of the HIV virus, that has been deactivated so it no longer produces the disease, as a vector that is“loaded” with the modified genes. Scientists must then introduce the vector into the patient’s cell. In order to do so, doctors collect hematopoietic stem cells from the patient’s bone marrow or peripheral blood, and culturally grow them in a lab. The hematopoietic stem cells are mixed with the vector, which then infects the stem cells and transforms them into “corrected” cells. At this stage doctors must ensure that the patient’s body will not reject the cells, to do this they use the process