Gene Technology Gene Therapy

Question 1

Examples Gene Therapy

Answer 1

Haemophilia B
Cystic Fibrosis

Question 2

Haemophilia B

Answer 2

Faulty allele of a gene on X chromosome.

Factor IX (blood clotting protein) not produced

Instead of IV injections of expensive Factor every 2-3 days - gene therapy provide single treatment - functional gene introduced liver cells via vector

Viral vector injected directly into body and targets liver cells where gene expressex

Question 3

Cystic Fibrosis

Answer 3

alleles that fail to produce trans-membrane conductance regulator protein - CFTR

Thick mucus collects in resp tract - interfering w/ gas exchange

Traditional treatment - physiotherapy to remove mucus

Gene Therapy - both adenoviruses and liposomes used as vectors for CFTR gene

Vector administered as aerosol into patients resp passages using inhaler - enters epithelial cells

Question 4

Benefits of Gene Therapy

Answer 4

Haemophilia B patients able to live free of need of regular injections

Huge potential for elimination of disease in which symptoms may be treated but no cure

Question 5

Medical Side Effects Gene Therapy

Answer 5

Some viruses used as vectors have been associated with disease on occasion

Viral particles and viral modified cells may be attacked by immune system - necessitating use of immunosuppressant drugs

Question 6

Practical Problems Gene Therapy

Answer 6

Many cells fail to take up new gene or fail to express it

Gene therapy treatments frequently need to be repeated

Cystic Fibrosis treatments short lived since epithelial cells do not live long - only cells in resp passages can be treated , not in pancreas

Question 7

Gene Knockout

Answer 7

GMO that carries a gene that has been made inoperative - leading to loss of gene function

Question 8

Gene Knockin

Answer 8

Exchanges a mutated DNA sequence for a normal sequence in gene, putting in place the function of the mutant gene

or

Human gene added in an orgs genome - human protein being prod in org

Question 9

What do Knockin and Knockout allow

Answer 9

Function of genes to be studied

Comparing how they differ in individuals provides information about what the gene does

Role of gene in protein production & its metabolic/physiological influence can be determined

Also both used in dev and testing of therapeutic drugs

Question 10

Knockout/Knockin Mice

Answer 10

Produced for studying human genetic diseases and also studying genes that become defective through mutation & cause cancer

Found that knocking out gene for p53 protein incr risk mouse gets cancer - indicates gene involved in ctrl of mitotic cells cycle

Knockin produced woth human immunoglobulin gene introduced - enable mice to prod humanised antibodies