Sts 5

• Gene therapy


  A medical approach that uses genetic material to prevent and treat disease
• Genetics


  The study of how genes and how are traits are passed down from one generation to the next
• Gene


  • The basic unit of heredity from parent to child
  • It contains instructions that tell your cells to make molecules called proteins
• Protein


  • Helps repair and build your body's tissues
  • Drives metabolic reactions, maintains pH and fluid balance, and keeps the immune system strong
  • Transports and stores nutrients and can act as an energy source
  • Crucial to good health
• If a gene is defective or missing

  • Can cause a medical condition called a genetic disorder
  • It would lack the ability to reproduce and pass on traits
  • Is also associated with malformations or diseases
• If a gene changes or mutates

  • Many mutations are harmful and can lead to genetic disorders or diseases
  • These mutations can disrupt the normal functioning of genes, leading to abnormal proteins, metabolic pathways, or developmental processes
• Gene mutation


  Caused by exposure to certain chemicals, ultraviolet radiations, other genetic insults or errors that occur during the process of replication
• If mutations are not corrected

  • It leads to permanent change in the sequence of the normal DNA
  • The mutations lead to disruption of the normal activity of the DNA or GENE
• Gene therapy


  • A medical approach that uses genetic material to prevent and treat disease
  • Seeks to modify or manipulate the expression of a gene or to alter the biological properties of living cells for therapeutic use
• Gene therapies can work by

  1. Replacing disease-causing gene with a healthy copy of the gene

  2. Inactive a disease-causing gene that is not functioning properly

  3. Introducing a new or modified gene into the body to help treat a disease
• Types of gene therapy

  • Somatic gene therapy
  • Germ line gene therapy
• Somatic gene therapy


  Involves transferring genes directly into targeted body cells
• Germ line gene therapy


  Affects all cells in an organism, including eggs and sperm, and so is passed on to future generations
• Diseases that gene therapy can treat

  • Cystic fibrosis
  • Alpha-1 antitrypsin deficiency
  • Hemophilia
  • Cancer
  • Beta thalassemia
  • Sickle cell disease
• Plasmid DNA


  Circular DNA molecules found in bacteria, which can be genetically engineered to carry therapeutic genes into human cells
• Viral vectors


  • The most effective means of gene transfer to modify specific cell type or tissue and can be manipulated to express therapeutic genes
  • They use the shell of the virus called CAPSID
  • They are like envelopes that are used to deliver messages
• Types of vectors


  • Viral vectors
  • Non-viral vectors
  • Bacterial vector
• Viral vectors


  Commonly used in gene therapy as delivery vehicles for introducing therapeutic genes into target cells
• Non-viral vectors


  Alternative delivery systems used in gene therapy that do not rely on viruses for gene delivery
• Bacterial vector


  Can be modified to prevent them from causing infectious disease and then used as vectors(vehicles) to carry therapeutic genes into human tissues