Definition: Thalassemias are forms of inherited autosomal recessive blood inherited in which the body makes an abnormal form of hemoglobin, which is an iron-rich protein in red blood cells. Thalassemias cause affected hemoglobin to be unable to utilize their transport function, causing the body to build fewer normal red blood cells and hemoglobin than normal, leading to anemia. Cause: Thalassemia occurs when there is a defect in a gene that helps control production of one of the two proteins that Hemoglobin consists of. Alpha or beta globin) Alpha thalassemia trait occurs if one or two of the four genes that are required to make sufficient alpha globin protein chains. If two or more of the genes are missing, medium to serious anemia occurs or cause mental retardation in some studies. ( (RJ. , 2012) Beta thalassemia occurs if two genes that are required to build sufficient beta globin protein chains are altered. The severity of beta alteration depends on how much one or both genes are affected. (G. , 2012) If both genes are affected, the result is moderate to severe anemia.
People that possess the highest concentration of the Thalassemia gene are Middle Eastern, Southern Asian, and African descent. (Azma RZ, 2012) Importance: Prevalence: Thalassemia is the “most prevalent genetic condition in Singapore” by Dr Angeline Lai, Head of Genetic Service, Department of Pediatrics, KK Women’s and Children Hospital. And she also quotes that: “About 5 per cent of our local population, or 1 in 20 persons, is a carrier for thalassemia, which could be Alpha, Beta Thalassemia or Hemoglobin E. (Xchange, 2012).
Complications of the disease: Patients suffering from moderate or severe thalassemia may be going through much pain if left untreated. This may result in heart failure and liver problems, resulting in the patient being more likely to develop infections. Severe thalassemia may cause early death due to heart failure and have to get regular blood transfusions and therapy to remove excess iron from the body. Although these blood transfusions can help control some symptoms, they may result in too much iron in the blood, which can damage the heart, liver, and endocrine system.
Financial cost: Info from thalassemia patients forum (Cost of Treatment for Thalassemia, 2010), all these treatment cost may add up to $20000 a year, and this is a real burden to bear for poorer families and to the government due to the medical subsidies. Treatment and Precautions: Precautions: We cannot prevent Thalassemias because it is inherited. However, we can conduct prenatal tests to detect these blood disorders before birth, and inform the parents to prepare them for the additional responsibilities of bearing the child.
Furthermore, Family genetic studies can be done to identify carriers of the missing or altered hemoglobin gene that causes thalassemia and inform them of the risk of passing the disorder to their children. Treatment: Treatments vary depending on the type and severity of the disease. Firstly, there is the blood transfusion in which patients receive leukocyte-reduced red blood cells for transfusion. This is not effective as patients have to do it regularly and there are complications like allosensitization which can create significant problems for patients. Chou ST, 2012) Next, Chelation therapy could be done using Desferrioxamine and Deferiprone to prevent or improve serious complications of Thalassaemia. These drugs have a retardation effect on the functional and structural changes during fruction and can slow down the rate of Hemoglobin becoming defective. (Sattarahmady N, 2012)
However, cost of this therapy was estimated at USD 30000 to 35000 which may be a serious economic burden for patients. Payne KA, 2007) Then there is the Bone Marrow Stem Cell transplantation which should be offered to patients as soon as possible especially if there is a HLA compatible sibling or family member. If there is no compatible transplant available, a suitable one should be found from an unrelated or alternative donor. However, this treatment may be risky as there is an 87% chance of thalassemia free survival rate for compatible donor and 70% chance for an alternative donor and a high 3 to 7 % mortality risk. Khalil A, 2012) Improve their livelihood: Patients are advised and feed a healthy diet, while avoiding taking in excess iron because this will cause iron overload. Patient’s quality of life is seriously compromised as they are limited to taking in only a few types of food and are occasionally feed on only IV drips. Alternatively, patients also are given many antibiotics to avoid potentially dangerous infections due to a weaker immune system and are advised especially to take in flu and pneumococcal vaccine to prevent infections. Although this works well temporarily, this is not a long term solution to the infection problem.
It is extremely costly to the patient and there is also a sizable chance that the patient might still get infected which will have often serious consequences. Ideas if we gain the financial aid: 1. The most effective way I would suggest is the use of gene therapy in replacing the defective gene in the bone marrow stem cells which is already in research today. More specifically, this would be to insert a normal hemoglobin gene into the stem cells in the bone marrow. (Chang CJ, 2012) This will allow people with thalassemias to make their own healthy red blood cells.
I would suggest using early experimentation on animals like mice to make sure that the method is safe for human clinical trials. 2. Secondly, researchers are researching ways to allow the human body to build fetal hemoglobin after birth. Making more fetal hemoglobin might make up for the lack of healthy adult hemoglobin. 3. More effective antibiotics could be engineered and made available for thalassemia patients. This is because due to their weaker immune system, thalassemia patients are required to take in antibiotics to ward of infection.
The creation of more effective antibiotics will greatly improve their quality of life. Why use mice as animal model for gene therapy? The reason is that the genetics of mice are very similar to that of humans. Genome sequencing of mice and other mammals show that there is cross-species genomic similarity. This greatly increased the value of using mice as animal models for research on human disorders. Application of knowledge to human society: 1. Gene therapy research could potentially unlock more secrets regarding the human genome.
Furthermore, the research will also be able to find out more about insertion of genes into our genome and the use of vectors, which could be applied to gene therapy for other human disorders. 2. The improved and more effective antibiotics can also be used for non-Thalassemia patients as well. This can be used especially for patients also suffering from weaker immune systems. Potential controversies and social implications: 1. the advances in gene therapy might result in people inserting favorable genes in fetuses to create designer babies. This may be seen as unethical.
Furthermore, this may lead to the huge decrease in the size and variety of the human gene pool, which may lead to humans becoming more susceptible to diseases and unknown diseases maybe more lethal. 2. Using fetal hemoglobin in babies in the method mentioned above may be deadly unborn or newborn babies. As the body of fetuses is small and fragile, extracting or inserting substances may be deadly to babies. This may be seen as murder of unborn fetuses, also having thalassemia does not mean that the baby will die, thus curing thalassemia maybe better than using fetal hemoglobin.
Cost of Treatment for Thalassemia. (2010, September 1). Retrieved September 28, 2012, from Thalassemia Patients and Friends: http://www.thalassemiapatientsandfriends.com/index.php?topic=3656.0 Azma RZ, A. O. (2012, July). Prevalence of iron deficiency anaemia and thalassaemia trait among undergraduate medical students. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23007811 Chang CJ, B. E. (2012, September 21). Zinc-finger nuclease mediated correction of ?-thalassemia in iPS cells. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23002118 Chou ST, L. R. (2012, October 4). Challenges of alloimmunization in patients with haemoglobinopathies. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23034087 G., L. (2012, Oct 1). The Search for Genetic Modifiers of Disease Severity in the ?-Hemoglobinopathies. Retrieved 7 October, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23028136
Khalil A, Z. I.-N.-A. (2012, September 28). Factors Influencing Outcome and Incidence of Late Complications in Children who Underwent Allogeneic Hematopoietic Stem Cell Transplantation for Hemoglobinopathy. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23020512 Payne KA, D. M. (2007, October 4). Clinical and economic burden of infused iron chelation therapy in the United States. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/17880607 RJ., G. (2012, Oct 1). ?-Thalassemia, Mental Retardation, and Myelodysplastic Syndrome. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov: http://www.ncbi.nlm.nih.gov/pubmed/23028133 Sattarahmady N, H. H.-M. (2012, August 15). Desferal as Improving Agent for Hemoglobin Fructation: Structural and Functional Impacts. Retrieved October 7, 2012, from http://www.ncbi.nlm.nih.gov/: http://www.ncbi.nlm.nih.gov/pubmed/23011645 Xchange, H. (2012, April 23). 5 Health conditions of special concern in Singapore. Retrieved September 28, 2012, from sg.news.yahoo.com: http://sg.news.yahoo.com/blogs/fit-to-post-health/5-health-conditions-special-concern-singapore-114644436.html