Topic 8—B: Genome Projects and gene Technologies- 5. Gene therapy

Question 1

What is gene therapy?

Answer 1

Recombinant DNA technology could also be sued to treat human diseases

Question 2

What does gene therapy involve?

Answer 2

• altering the defective genes (mutated alleles) inside cells to treat genetic disorders and cancer

Question 3

How you do this depends on?

Answer 3

• whether the disorder is caused by a mutated dominant allele or 2 mutated recessive alleles

Question 4

If its caused by 2 mutated recessive alleles what can you add?

Answer 4

• a working dominant allele to make up for them- you ‘supplement’ the faulty ones

Question 5

If its caused by a mutated dominant allele what can do silence?

Answer 5

• ‘silence’ the dominant allele (e.g. by sticking a bit of DNA in the middle of the allele so it doesn’t work any more)

Question 6

What do both of these processes involve?

Answer 6

• inserting a DNA fragment into the persons original DNA
• just like in recombinant DNA technology you need a vector to get the DNA into the cell
• A range of different vectors can be used e.g. altered viruses, plasmids or liposomes (spheres made of lipid)

Question 7

What are the 2 types of gene therapy?

Answer 7

Somatic therapy
Germ line therapy

Question 8

Somatic therapy

Answer 8

This involves altering the alleles in body cells, particularly the cells that are most affected by the disorder

Question 9

What does somatic therapy not affect?

Answer 9

• The individual sex cell (sperms or egg) though, so any offspring could still inherit the disease

Question 10

What is germline therapy?

Answer 10

• This involves altering the angles in the sex cells
• This means that every cell of any offspring produced from these cells will be affected by the gene therapy and won’t suffer from the disease
• Line therapy in humans is currently illegal though

Question 11

Ethical issues surrounding gene therapy

Answer 11

• Some people are worried that the technology could be used in ways other than for medical treatment such as for treating the cosmetic effects of aging
• Other people worry that there’s the potential to do more harm than good by using the technology (e.g. Risk of over expression of genes- gene produces too much of the missing protein)