Gene Therapy Flashcards
What is the cause of cystic fibrosis?
It is caused by a deletion mutation where a mutant recessive allele is missing three DNA bases, adenine-adenine-adenine
What is the name of the faulty gene that causes cystic fibrosis?
CFTR
What is the role of CFTR?
To transport chloride ions out of epithelial cells
What does the CFTR gene affect?
Osmosis
How are the epithelial membranes affected by cystic fibrosis?
They are dry and the mucus they produce remains viscous and sticky
What are some of the symptoms of cystic fibrosis?
Mucus congestion in the lungs, breathing difficulties, thick mucus in the pancreatic ducts and sperm ducts in males which can lead to infertility
In what two ways can gene therapy be used to treat cystic fibrosis?
Gene replacement and gene supplementation
Which is involved in gene replacement?
The defective gene is replaced with a healthy gene
What is involved in gene supplementation?
One or more copies of the dominant healthy gene are inserted alongside the defective gene
What is germ-line therapy?
It involves replacing or supplementing the defective gene in the fertilised to ensure that all of the cells of the organism will develop normally, as will the cells of their offspring
What is somatic cell gene therapy?
It involves targeting the affected cells which is a short term solution and does not ensure that the functional gene is passed on to future generations
How somatic cell gene therapy treat cystic fibrosis?
The cloned, normal genes can be introduced into the lungs using a harmless virus that is inhaled through the nostrils of patients or the functional gene could be wrapped in lipid molecules (forming a liposome) that allow the CFTR gene to cross the phospholipid portion of the cells surface membrane and are also sprayed into the nostrils as an aerosol
Define gene therapy
A mechanism by which genetic diseases, e.g cystic fibrosis, may be cured by masking the effect of the defective gene through the insertion of a functional gene
