Genetic Disorders That Can Be Treated with Gene Therapy
What is a genetic disorder?
Genetic disorders are the defects in the genes of a person. Most of them are multi-factorial hereditary illnesses, like Huntington’s disease and Parkinson’s disease. A few of them occur due to environmental hazards. It is estimated that there are 4000 to 6000 genetic disorders, which have been diagnosed already (Genetic Disorders, 2014).
Interest and relevance
Genetic disorders will have an adverse effect on the patients, and that makes their life horrible. Though there are no treatments for these rare genetic conditions, supportive care can bring relief to some extent. However, it is found that most of such treatment strategies fail to change the mutation of the genes. It is in this context that the application of gene therapy has increased the hope of medical professionals in overcoming and controlling such failures in the treatment of genetic disorders (How are genetic conditions treated or managed, 2014).
Gene therapy and principles of heredity
The principle of segregation states that for any particular characteristic, the pair of alleles (inherited factors) of parents separate in order to ensure that only one allele is transmitted to the young ones (Pierce, 2010). During reproduction, the process of meiosis is responsible for separating inherited factors during fertilization. It is during meiosis that the separation of alleles of genes into reproductive cells usually occurs.
Independent assortment is the second principle of heredity. It states that all genes located on chromosomes are independently inherited or simply transmitted autonomously. However, there are some exceptions to the principles of inheritance. For instance, if the genes are sex-linked, the principle of independent assortment does not apply (Pierce, 2010).
Gene therapy mostly uses somatic cells (body cells-diploid not reproductive cells-haploid) as targets for transferred cells (Pierce, 2010). This type of therapy is referred to as somatic gene therapy. Healthy genes are transferred into the somatic cells of the body of a person who has a genetic disorder. The procedure involves a single target tissue (deformed tissue) and only one person if treated. They are mainly aimed at correcting a genetic disorder.
There are two types of gene therapies that are not yet in use. They are germ-line gene therapy that targets reproductive cells. Their aim is to pass certain desired characteristics to the next generation (Cummings, 2013). Enhancement gene therapy, on the other hand, entails gene transfer to enhance traits like intelligence especially to those who are mentally retarded.
Application of molecular genetics for genetic variation
Molecular genetics entails the study of not just the structure, but also the function of genes (Cummings, 2013). The storage of heritable genetic information is usually in the form of long strands of deoxyribonucleic acid (DNA). DNA is a stable molecule found in the nucleus of cells and is replicated and passed to other generations. DNA Segments can encode genes or functional elements that are transcribed into mRNA (Pierce, 2010). Messenger Ribonucleic Acid is then in the process of translation or serves as the protein synthesis template. At times, this process leads to gene mutation.
When a mutated gene makes the protein it encodes unable to function properly. Generally, when this happens, the entire body or organ may not function properly. In fact, somebody’s organs may end up being permanently deformed a good example is cleft palate (Pierce, 2010). Gene therapy is the best way of fixing such physiological issues. In this case, it can be fixed by adding a normal copy of the deformed gene. In short, this can lead to the production of normal proteins leading to the normal functioning of the deformed body organs (Cummings, 2013).
When compared with drug-based interventions, gene therapy works differently by simply repairing the genetic defect. This is done by modifying the cells of the underlying organ with the genes that function properly. The new gene can be inserted or transferred in two different ways: Ex vivo and in vivo (Pierce, 2010). With this, the body will be making proteins based on the instructions from the newly inserted gene.
One major underlying principle is that gene therapy must be done many times for the affected person to be continually relieved. In the case of the inherent metabolism errors caused by the shifts in genes that influence the construction of certain enzymes, dietary deviation and enzyme substitution treatments can bring progress in some genetic disorders. However, the improvement will be very slow (How are genetic conditions treated or managed? 2014).
Genetic disorders cured with gene therapy
Some of the genetic disorders that can be treated with gene therapy are Severe Combined Immune Deficiency and Chronic Granulomatous Disorder. ADA-SCID affects children who are born without well functioning immune system (Cummings, 2013). The gene therapy known as ADA has been found to effectively treat patients with Severe Combined Immune Deficiency (Pierce, 2010). The gene is introduced in the bone marrow cells of the affected persons. There is no confirmed or established side effect associated with the ADA gene therapy (Pierce, 2010).
Other major genetic disorders like hemophilia and congenital blindness are curable through gene therapy. Acquired diseases are treated with different gene therapies (Cummings, 2013). Such therapeutic strategies include gene vaccines and oncolytic biotherapy. However, for neurodegenerative illnesses like Parkinson’s, the best therapy is the Novel gene. Different acquired diseases are also treated with gene therapy techniques. Research is in progress to develop new gene therapy techniques to fight viral infections, diabetes and heart diseases (What Diseases Can Be Treated with Gene Therapy, 2011). The recent discovery of chromatin architecture that controls the gene activity is a milestone in the diagnosis of genetic disorders (Institute de researches Clinique de Montreal, 2014).
Bioethical issues
Despite all these developments in gene therapies to treat genetic disorders, applying the gene therapy itself is a challenge for medical professionals (Pierce, 2010). In human beings, gene therapy raises a range of important legal, social as well as ethical issues. For instance, somatic gene therapy has been found to be comparable to the existing medical approaches. That is, its main goal is to either prevent or treat diseases or unhealthy conditions in people (Cummings, 2013). Somatic gene therapy raises questions regarding the efficacy and safety of treatments as well as protection for human subjects used in research.
Germline gene therapy, on the other hand, is different from conventional medicine as it entails some aspect of manipulating the human genome in order to ensure that children are not bone with genetic disorders (Pierce, 2010). In fact, unlike Somatic gene therapy, germline gene therapy is always subject to much controversy. Some quarters hold that it creates some dangers to both the affected persons and their generations in the future.
Last but not least, genetic enhancement is associated or linked to a number of complex issues comprising the ethics of completely changing the inheritable characteristics of human beings, lack of parental control over the lives of their children (Pierce, 2010). Finally, genetic enhancement is thought by many to exacerbate social eugenics and inequalities. Moreover, the insertion of new genes into the cells of a body is an elaborate and costly process, and developing gene therapy for rare genetic disorders is very sophisticated. It needs many clinical trials to obtain government approval, prior to its application as specific gene therapy. These are long-standing issues in gene therapy treatment for genetic diseases as well as acquired diseases (Genetic Science Learning Center, 2014).
Personal Stand
Recognizing that gene therapy raises a number of questions regarding its safety both to the affected person and future generations, the opponents must understand even the medical treatment they use were subjected to similar scientific research and were proven to be good for treating diseases. Therefore, even though gene therapy is a new idea, science has already indicated that some gene therapy does not have any adverse effect on both patients and their future generations. Furthermore, it is patients who should choose their own medication through informed consent. Informed consent, in this case, should involve the patient if he or she is of sound mind, but if the patient is in a critical situation then the medical practitioners should seek informed consent from close relatives. In so doing, the existing dilemma will have been eliminated. Therefore, gene therapy is safe and good for patients with genetic disorders.
References
Cummings, M. (2013). Human Heredity: Principles and Issues. Manson: OH: Cengage Learning.
Genetic Science Learning Center. (2014) Challenges in Gene Therapy? Learn. Genetics. Web.
Genetic Disorders. (2014). Web.
How are genetic conditions treated or managed? (2014). Web.
Institute de Recherches cliniques de Montreal. (2014). Important discovery for diagnosis of genetic diseases. ScienceDaily. Web.
Pierce, B. (2010). Genetics Essentials; Concepts and connections. New York, NY: W.H. Freeman and Company.
What Diseases Can Be Treated with Gene Therapy? (2011). Web.