Genetic Pre-Disposition in Cancer. Flashcards
What is the cause of most cancer?
Sporadic mutations.
What can increase people’s risk of cancer?
A genetic inherited pre-disposition for cancer.
Genetic pre-dispositions for cancer are spread from generation to generation, but what may start them?
Germ Line Mutation. (in sperm or eggs)
What is another name for germ line mutation?
De novo mutation.
If there is a germ line mutation, which cells in the child’s body are affected by this mutation?
All of them.
Name three genes associated with an increased risk of cancer.
Oncogenes
Tumour suppressor genes
DNA damage response genes.
What are oncogenes called when they are functionalling normally?
proto-oncogenes
How many mutations do proto-oncogens require to ecellarate cell growth, which could lead to cancer?
Just one.
How many mutations do tumour suppresser genes require for ‘both breaks to fail’, and for them to be unable to prevent cell growth?
2 mutations. First can be hereditary - someone with this mutation is more likely to get cancer.
What do DNA damage response genes usually do?
Repair DNA if something has gone wrong.
How many mutations would cause the DNA damage response gene to be unable to stop the accumulation of mutations in other critical genes?
two.
What is micro satellite instability?
When the Mismatch repair gene doesn’t work, then many nucleotide units can be added on.
What is the syndrome called when you require two recessive, abnormal genes to be passed down to cause cancer?
Autosomal recessive syndrome.
What might explain having a history of cancer, but no identified mutations.
Multiple modifier genes of lower genetic risk.
How can you tell if someone has a pre-dispotion for cancer?
Check their family history. Could do mutation testing, surveillance - and if needs be, surgery.
