What is Gene Therapy and what is it used for?
Gene therapy (otherwise known as somatic gene therapy or therapeutic gene therapy) is a process that is used to correct defective genes responsible for development of various diseases. (www.accessexcellence.org/RC/AB/BA/Gene_Therapy_Overview.php) There are two main types of gene therapy; somatic (body) cell gene therapy and germ line gene therapy. As it suggests, somatic gene therapy is correcting the faulty genes of normal body cells. Germ line therapy is altering genes in gametes. Everyone on earth carries a few defective genes. Most of us are unaware of this fact however, unless we are afflicted with a genetic disease. Approximately one in ten people have, or will develop, a disease that is a direct result of faulty genes. (www.ghr.nlm.nih.gov/handbook/therapy/genetherapy)
The possible future uses for gene therapy are seemingly endless, with current research of gene therapy underway on how it can be used in the treatment of cancer, genetically caused blindness, and sickle cell disease. (www.cancer.gov/cancertopics/factsheet/therapy/gene)
What are the concepts and processes involved in Gene Therapy?
The general process by which scientists correct these genes are by that the absent or faulty gene is replaced by a working gene, so the body can make the correct enzyme or protein and therefore eliminate the cause of the disease. (www.accessexcellence.org/RC/AB/BA/Gene_Therapy_Overview.php)
There are two methods used to insert genetic material into human chromosomes. The first of which, called in vivo technique, a normal gene is inserted into the chromosome to replace the abnormal, disease causing one. A carrier molecule (called a vector) is used to transfer the correct gene to the patient’s target cells. (www.ornl.gov/sci/techresources/human.../genetherapy.html) The most common vector used today is a virus. This is because viruses are able to deliver their genes to human cells (such as the influenza virus) which usually are pathogenic. Scientists have removed that original disease causing genes of the viruses and insert the needed correct genes for the human target cells. (www.ghr.nlm.nih.gov/handbook/therapy/genetherapy)
The target cells are then infected with the virus vector. The vector then unloads its genetic material (which contains the needed correct genes) to the target cell. The correct gene is then able to generate the correct functional protein and so restores the target cell to the normal state. (www.ghr.nlm.nih.gov/handbook/therapy/genetherapy)
The reason why carrier molecules are usually needed is because otherwise correct genes could only be inserted in certain tissues and would require a large amount of DNA. (www.ndsu.nodac.edu/instruct/mcclean/plsc431/students/bergeson.htm)
The second method is called ex vivo technique, and involves surgically removing cells from affected tissues, injecting the new DNA that will correct the disease into the cells and letting...