Can genetic diseases like cystic fibrosis, hemophilia and muscular dystrophy be cured by gene therapy?Genetic diseases and gene therapy:Genetic diseases are pathological diseases caused by the absence or alteration of one or more genes in the cells of an organism. Most genetic diseases are caused by inheriting an altered or missing gene from one or both parents. Since the edited gene is found in every cell in your body, including your stem cells, it is virtually impossible to physically edit the gene. The only possible effective method that has been found is gene therapy. Gene therapy involves inserting normal or genetically modified genes into cells to replace defective genes. The gene is usually inserted into an organism's cells using a genetically engineered virus that injects the desired gene into the organism's cells, rather than a harmful disease.Fig. 1: A diagram showing two types of gene therapy Source: http://www.stemcells.nih.gov Cystic fibrosis: Cystic fibrosis (CF) is a genetically inherited disease that affects the lungs, pancreas, liver and intestine . Cystic fibrosis is caused by alteration of the cystic fibrosis conductance regulator (CFTR) gene. Because the alteration is recessive, you must receive an altered CFTR gene from both parents to have CF. The alteration causes the abnormal transport of sodium and chloride across a membrane. This causes thick mucus to form on the membrane which can block airflow in the lungs. Thick mucus in the lungs also causes frequent lung infections.Fig. 2: A diagram showing the inheritance of the CFTR gene. Source: http://www.nhlbi.nih.gov/ Although cystic fibrosis poses many threats, the greatest threat is to the lungs, as thick mucus makes the lungs vulnerable. .... middle of article...... the University of Missouri tested the use of adeno-associated viruses as a gene vector on 22 dogs. The result of the treatment was a drastic reduction in muscle inflation and fibrosis in all 22 dogs. All dogs also showed improved strength. In some cases, dogs with difficulty walking were able to run after treatment. The images below show the muscle of one of the dogs before and after treatment. The rounded cells are dead cells and the blue parts are inflammation.Fig. 6: Muscle cells from a dog with DMDSource: www.nbsubscribe.missouri.eduFig. 7: Muscle cells from the same dog after gene therapySource: www.nbsubscribe.missouri.eduConclusion:The results of the tests on dogs appear promising and could lead to a cure for MD in the future. more human testing and clinical trials need to be done before the evidence can be conclusive.