Transcript 5.2.3 Gene Therapy - Mrs Miller's Blog | Science Revision

5.2.3 Gene Therapy
• explain the term gene therapy;
• explain the differences between somatic cell
gene therapy and germ line cell gene therapy;
• discuss the ethical concerns raised by the
genetic manipulation of animals (including
humans), plants and microorganisms
Gene Therapy
• Using genetic technology to treat genetic
disorders
• Getting a working copy of a gene into cells
that contain dysfunctional copies of the gene
Somatic Cell Gene Therapy
• Certain genes switched on and off in
differentiated cells
• Augmentation = adding functioning genes into
the relevant specialised cells meaning that the
protein can be made and the cell will function
normally
• Killing Specific Cells = making cancer cells express
genes producing proteins that make their cells
vulnerable to attack by the immune system for
targeted cancer treatments
Germline Gene Therapy
• Stem cells that could become any type of cell or a new human
being
• Germline therapy is changing the genes of the first few cells
meaning that the organisms is different
• Somatic cell therapy is changing genes on part of the body, however
the disease can still be inherited as the gene still exists in every
body cell and gametes
• Germline gene therapy is altering the organisms genes before
development into a fetus, however this is illegal in humans because
they say:
• New human disease could be created
• Human evolution would be interfered with
• Too many ethical and moral issues with changing a human genome
Issues
Somatic Cell Gene Therapy
• Getting genes into target cells is tricky
• Treatment is short-lived and has to be repeated
• Difficult to get the gene functioning in the genome
• Only the actual patient affected
Germline Gene Therapy
• More straightforward to deliver gene into cell
• All subsequent cells will have the functioning gene
• Considered unethical
• Genetic manipulation passed onto children- could be a
good or bad thing
Xenotransplantation
• 60% transplant patients die on the transplant list
• We can now consider xenotransplantation= transplants from other
species
• Pigs have been genetically engineered so they do not produce an
enzyme involved in organ rejection
Problems
• Different organ size
• Pigs only live to 15, so organs may age quickly
• Pigs body temperature is 39⁰C, our is 37⁰C
• Animal welfare groups think killing animals for organs is wrong
• Jews and Muslims cannot eat pork, so could not have transplants
• Possible disease transfer between animals and humans
Genetic Manipulation
• What is wrong with moving a gene from one
organisms to another?
• Selective Breeding is unnatural?
• Media call food ‘Frankenfood’ but are not aware
that we eat DNA all the time and think that it will
become part of out DNA if we eat it...
• There were objections to the first vaccinations,
the first organ transplant, IVF babies...