Cancer genetics Flashcards
What is variable expression
A mutation in a single cancer gene can predispose to different tumours in the same individual
What is age-related penetrance
It takes time for an individual to accumulate the other hits necessary to cause a tumour
What are mutator genes
Maintain the integrity of the genome
What are the inherited cancer predisposition genes
- Protooncogenes
- Tumour suppressor genes
- Mutator genes
What are 1% of colorectal cancer cases due to
Mutations in APC
What are 5% of colorectal cancer cases due tp
Mutations in one of HNPCC
What are syndromes caused by mutations in proto-oncogenes
Multiple endocrine neoplasia type 2
Hereditary papillary renal carcinoma
What are syndromes caused by mutations in tumour suppressor genes
- Breast and ovarian cancer
- Thyroid cancer
- Young onset cancers particularly sarcoma and breast
When can a cell initiate a tumour
When it contains 2 mutant alleles
If there is a high general population risk, what should you do in terms of testing
Surveillance indicated
Secondary care +/- genetics
Gene testung
What if there is a moderate risk what would you do
Surveillance indicated
secondary care
What if there is a low risk what would you do in terms of testing
Surveillance not indicated
What is the syndrome called when there is a sarcoma _ breast cancer
Li-Fraumeni syndrome
If there is ovarian, endometrium and bowel cancer, what mutation is it
HNPCC
if there are 4 relatives with bowel cancer, what type of risk is it
High risk
