Gene Therapy Case Study

Gene Therapy has been tested a Jacob sheep model, a rare sheep breed. It found the biochemical mechanism in the sheep was identical to humans and a mutation that resulted in an exon deletion via slipicing. Gene Therapy is still being researched by The Tay-Sachs Gene Therapy (TSGT) Consortium, so it is not officially being used. Since, 1980, 20 people have received Caravan gene therapy. This is a possible option for my child since, of most of the parents said their child benefited from the therapy but is a little risky since not many tests have been

In fact, over half of X-SCID patients have no family history of immune disorders and are considered to be de novo cases. Having an affected child does not mean that fathers are carriers, as they will never pass their X chromosome to their son. Affected fathers will always pass the mutation on to their daughters, making them carriers. Traditionally, if a mother is a carrier of an X-linked disease, they have a 50% chance of passing along the mutation to any progeny. However, in X-SCID, there is germline mosaicism of the X chromosome in mothers, so they may not appear to be carriers by a blood sample genetic test but are in fact carriers of the mutation. Germline mosaicism makes it difficult to screen potential parents for carrier status, as the mothers will not always appear to be carriers. Additionally, a son affected because of germline mosaicism may appear to have a de novo mutation, leading to the conclusion that siblings are not at an increased risk of inheriting the disorder when they in fact are. As a consequence of these difficulties in determining carrier status, females are generally not tested for carrier status unless they have a son who is affected, and in general, genetic testing is most helpful if the son’s pathogenic variant in IL2RG has been identified [2].

In 1995, Timothy Ray Brown, more commonly known as the Berlin patient, was diagnosed with the HI Virus and like many patients, he began using HAART and expected a more normal life. However, in 2006 he was diagnosed with acute myeloid leukemia, which is treated in Europe with a stem cell transplant. In 2008, Mr. Brown agreed to a risky stem cell transplant, knowing that only %50 of patients survives. With the odds against him, he also agreed to a special treatment that would inject stem cells from a donor that had a natural immunity to the HI Virus, in an attempt to cure both the cancer and the virus at one time. Against all odds Mr. Brown survived the treatment, and both ailments were cured. Regardless of how extraordinary this cure was to find, it is not a broad case cure. The ability to match donor’s chromosomes for stem cell transplants is currently a daunting task; trying to find donors that contain the mutated gene that has a natural ability to resist the HI Virus would match less than .01% of the infected population. Although we have found this small victory, we must continue the search for a

When putting the “Bubble Boy Disease” in the past, gene therapy can be the time machine to send it back. Gene therapy can help replace infected cells in a patient’s body with healthy, new cells. SCID is a severe disease that can be greatly impacted by gene therapy. New advancements are being made and a gene therapy method can be used to transfer bone marrow into the patient, instead of transferring the cells. The future of gene therapy can help cure SCID.

Severe combined immunodeficiency (SCID) is a term that describes a broad range of genetic disorders that cause profound defects in the humoral and cellular immune system in humans. Patients that have been diagnosed with SCID usually record a low T cell and natural killer (NK) count in their body. On top of this, patients usually have a high number of B cells, but are usually deficient in specific antibody responses (Allenspach, et al., 2003). SCID can be treated through a bone marrow transplantation (BMT) operation and gene therapy. Patients who do not get treatment usually die in infancy due to infections caused by opportunistic pathogens that are able to thrive in the body due to a weakened immune system. There are two forms of SCID,

Fifty years after the idea of gene therapy was first proposed, gene therapy has become a possible treatment for a couple different diseases. Before this treatment was approved, some serious unfavorable effects were found in clinical trials. However, these effects fueled more basic research in order to improve, in efficiency and safety. Gene therapy has been used for patients with blindness, neuromuscular disease, hemophilia, immunodeficiencies, and cancer.

Severe combined immune deficiency (SCID), is developed by an unusually and recurring severe infection or cancer (2014, Patton & Thibodeau p434). The boy in the bubble immune system is ineffective, feeble, and defenceless against infection. The purpose of isolating him is to keep him free from germs and viruses. Placing him in isolating will provide a sterilized environment with filtered air, to eliminate infections. One way to cure the bubble boy gene is by injecting bone marrow stem cells, into the patient. The bone marrow stem cells contain a missing enzyme gene that can make the immune system healthy. Individuals suffering with this rare disorder may consider a bone marrow transplant. (2014, Patton & Thibodeau) A bone marrow transplant will help cure the disease and prevent it from becoming fatal.

In 1990 the first gene therapy procedure gained approval and a four-year-old girl with SCIDs disease was finally able to fight off a simple cold. She is now able to live a normal life with the help of continued treatment of gene therapy. Although gene therapy is an innovative and ideally favorable procedure when it comes to treating diseases, cancer, or inherited disorders, it is still a delicate procedure and is continuously studied to insure it is not only effective but also and most importantly safe. In order to insure the safety of patients a gene therapy drug must get the approval of the FDA before becoming available, as every drug must do. Since gene therapy is still very experimental; there are only a few gene therapy drugs that have been approved by the FDA to treat patients. However, on August 30th, 2017 history was made when the FDA approved Kymriah, the first CAR-T cell therapy drug to be available in the United States. Kymriah is a one-time treatment for patients with B-cell acute lymphoblastic leukemia, it was developed through the research collaboration of Novartis and the University of Pennsylvania, and it is manufactured for each individual patient. Kymriah’s only drawback would be the price tag of $475,000 for a course of treatment, however Novartis plans to wave the fee for patients where Kymriah is not successful.

SCID is caused by genetic defects. These defects are either inherited from the parents or result from a new mutation formed in a

The cultured stem cells were then infected with the genetically altered viruses containing the functional SBDS gene through transformation. The patient’s cells, after being genetically altered with the therapeutic gene, were reintroduced into the patient’s body. The reintroduction took place by using a needle to inject the cells back into the patient’s spinal bone marrow. After six months the patient was brought back in to check for symptoms as well as take DNA samples to determine if function of the SBDS gene was restored and mutations were

Corrective gene therapy may offer help with specific and corrective therapy for genodermatoses. These clinical applications have been most successful in genetic modification. Recently large amounts of therapeutic approaches have proven clinical benefits for genodermatoses. Theses studies must surpass HLA limits, then maybe one day gene-correcting cell therapy may be further researched.

In a clinical trial conducted in the United States, the therapeutic gene was introduced into the liver of patients, who then acquired the ability to have normal blood clotting time.” Gene therapy also cured ADA-SCID disease which is known as bubble boy disease (American Society of Gene & Cell Therapy, 2015). ADA-SCID disease affects children who born without immune system (American Society of Gene & Cell Therapy, 2015). According to American Society of Gene & Cell Therapy (2015), “the therapeutic gene called ADA was introduced into the bone marrow cells of such patients in the laboratory, followed by transplantation of the genetically corrected cells back to the same patients. The immune system was reconstituted in all six treated patients without noticeable side effects, who now live normal lives with their families without the need for further treatment.”

There are three techniques that researchers are working on. The first and most common is ex vivo ( or "outside the living body") therapy. The defective cells are removed from the patient and replaced with the normal DNA before returning to the body. This therapy targets the blood cells because many genetic defects alter the functioning of one type of these cells or another. But since blood cells have limited life spans follow-up treatments are required. Future efforts will most likely target stem cells of the bone marrow. Stem cells are ideal for gene therapy because they appear to be immortal. Researchers have obtained stem cells from human bone marrow, but they are having difficulties getting genes into the cell as well as inducing the cells to produce many new blood cells (Anderson, 1995).

If a treatment is implicated before the child is born – germline gene therapy – he or she could lose all trace of that defective gene, and therefore wouldn’t pass the disease on to future generations. In somatic gene therapy, treatment is conducted when the patient is an

disease (NLM, 2014). The procedure uses a corrected gene and inserts it into a person instead of