Genetic Cancer Predisposition Flashcards
What kind of cancer does germline mutation cause?
Cancer Syndrome or family cancer syndrome
what 3 types of genes are involved in pre-disposition to cancer?
Oncogenes
Tumour-supressor Genes
DNA damage-response genes
What is a proto-oncogene?
A normal gene that codes for proteins which regulate cell growth/differentiation
How does a proto-oncogene mutate?
To an oncogene
What is an oncogene?
The mutated form of a proto-oncogene
/What does an oncogene do
Oncogenes promote cell division, causing cancer when stuck in the “on” mode.
What do tumour supressor genes do?
Inhibit cell cycle & promote apoptosis
How many mutations are required to disable tumour supressor genes?
2, one for each “brake”
Explain the two-hit hypothesis?
The two mutations that disable the 2 tumour supressor genes leading to cancer.
1st mutation disables brake 1 (susceptible carrier)
2nd mutation disables 2nd brake (leads to canceR)
What is a cell called with one tumour supressor gene disabled?
A susceptible carrier
What are DNA damage response genes?
The repair mechanisms of DNA
How many genes are invlved in DNA repair?
2
How does the failure of DNA damage response genes lead to cancer?
When both genes fail the accumulation of mutations in other critical genes speeds up.
What is the MMR gene?
Mismatch repair gene.
What does a normal MMR gene do?
Repairs basic mutations