Sickle Cell Anaemia And Gene Therapy Biology Essay

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Gene therapy is the insertion, alteration, or removal of genes within a person's cell and biological tissues to treat diseases. The most common form of gene therapy involves the addition of functional genes into an unspecified genomic location in order to replace a mutated gene. Sometimes gene therapy includes viral processes for the therapy to succeed. Although the technology is still in its early stage, it has been used with some accomplishment.

Some diseases targeted by gene therapy are, Sickle-Cell Anemia (SCA), Hemophilia, and Cystic Fibrosis (CF). The first disease is Sickle-Cell Anemia (SCA), which is an autosomal recessive genetic blood disorder, with over dominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Researchers are experimenting with effort to cure sickle-cell disease by correcting the defective gene and inserting it into the bone marrow of those with SCA to stimulate production of normal hemoglobin.

The defective gene is in the hemoglobin. Bone marrow containing thee defective hemoglobin genes were inserted into the bone marrow of patients using autologous transplantation, in which some of the patient's own bone marrow cells would be removed and genetically corrected. The genetically corrected patients started producing high levels of normal blood cells and showed failure in the production of defected cells.

Symptoms of SCA are:

abdominal pain

bone pain


delayed growth




rapid heart rate

ulcers on the lower legs (in adolescents and adults)

yellowing of the eyes and skin (jaundice)

chest pain

excessive thirst

frequent urination

poor eyesight/blindness


SCA is usually inherited from parents who are carriers. They have only the trait that is a milder form of the disease, or one abnormal hemoglobin. Patients with sickle cell disease need constant treatment, even when they aren't in a serious condition. They should take supplements of folic acid because they are essential for producing red blood cells.

The treatment of SCA differs according to the frequency of the disease. The purpose of treatment is to manage and control symptoms, and to limit the frequency of emergencies. During a sickle cell emergency, you may need certain treatments. Painful frequencies are treated with pain medicines and by drinking plenty of fluids. Non-narcotic medications may be effective, but some patients will need large doses of narcotics. Hydroxyurea is a drug some patients use to reduce the number of pain frequencies, including chest pain and difficulty breathing. Antibiotics and vaccines are given to prevent bacterial infections, which are common in children with sickle cell disease. Blood transfusions are used to treat a sickle-cell anemia. They may also be used on a regular basis to help prevent strokes.

The second disease is Cystic Fibrosis (CF). CF is a common recessive genetic disease which affects the entire body, causing progressive disability and often early death. There have been several trials for curing cystic fibrosis, but the most widespread study deals with gene therapy. Adenoviruses, which are like gene carriers, have become on close study since they are able to infect human airways and result in only a minor sickness such as the common cold. The goals of gene therapy in this disease are to design an effective method of introducing the cloned gene into the cells and to make the gene function inside the somatic cell. To improve the function of the gene, the appropriate controlling basics of the gene must be determined, such as guiding a copy in suitable cells. Even though the development of gene therapy is uncompleted, problems have already ascended. The number of cells that must be correct for clinical benefit is unknown and the treatment may lead to over expression which could cause toxicity. The immune system may reject the route. Gene therapy is also surrounded by a plethora of ethical concerns. The questions of when to treat a patient, who to treat, authorization of a minor treatment, and cost effectiveness of the procedure all have a benefit on the future of gene therapy for cystic fibrosis.

Symptoms of CF include:

delayed growth

failure to gain weight normally during childhood

no bowel movements in first 24 to 48 hours of life

salty-tasting skin

nausea and loss of appetite

weight loss

coughing or increased mucus in the sinuses or lungs


nasal congestion caused by nasal swellings

recurrent incidents of pneumonia


increased coughing

increased shortness of breath

Cystic Fibrosis is a genetic disorder. A child must inherit a specific gene from both parents to get cystic fibrosis. An early diagnosis of CF can help the patient in survival. Monitoring is very important.

The third disease is Hemophilia, or a group of bleeding disorders in which it takes a long time for the blood to clot. The main symptom of hemophilia is bleeding. In more severe cases bleeding can occur with no reason. Internal bleeding is possible especially in the joints.

The average cost of gene therapy is $100,000 per individual. However, the genetic testing is also expensive. Genetic testing may vary from hundreds to thousands. The therapy itself differs according to diseases. Many people cannot afford the payments of gene therapy. Since gene therapy is still experimental people should pay more money for the therapy to receive good results. C:\Documents and Settings\Owner\Local Settings\Temporary Internet Files\Content.IE5\A32993HW\MP910216577[1].jpg

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There are many causes of gene therapy being fatal. Some are that gene therapy isn't professional yet, the expenses, and that it may not cure the patient successfully. I think that gene therapy shouldn't be used more often because it is still experimental and has a very low expectancy of succeeding. It may probably be fatal at some point related to the disease. Many people couldn't afford the expenses of gene therapy, so it is very low to be often done. And the last factor is that scientists haven't yet discovered cures of specific disease or they found the cure but it doesn't treat the disease successfully. People can spend money on the therapy but get no good results.