Genetic predisposition to cancer Flashcards Preview

Principles of disease JK > Genetic predisposition to cancer > Flashcards

Flashcards in Genetic predisposition to cancer Deck (15):
1

What is Cancer?

A common disease of somatic cells that are mostly due to chance and most are non-inheritable although increased chance with genetic predisposition

2

Oncogenes

1 mutation is sufficient for cancer and accelerates cell division
Protooncogene ==> Oncogene
Eg Thyroid cancer or by a virus

3

Tumour suppressor genes

1 mutation already in carrier eg BRCA1/2
Cells breaks which inhibit cell cycle and promote apoptosis
2 hit hypothesis

4

DNA damage response genes

Repair DNA and both genes fail = CANCER
Eg colon cancer

5

Base pair mismatch

Either have normal repair or defective repair (MMR+) which leads to MSI

6

Microsatellite instability

Addition of nucleotide repeats

7

Other causes of cancer include

Autosomal recessive syndrome
Multiple modifier genes which explains families with history but no mutation

8

De Novo Mutation

Mutation occurs newly in germ cell of parent

9

Most cancer susceptibility genes are...

Dominant with incomplete penetrance

10

Risks for breast cancer

Age, alcohol, diet, late menopause, no children, oestrogen use

11

BRCA 1

Checkpoint mediator for DNA damage signal and repair which remodels chromatin

12

Risks for colorectal cancer

Age, high fat, low fibre, IBS

13

How to manage cancer risk in Adenomatous polyposis syndrome

Surveillance, surgery, chemoprevention eg steroids

14

Predictive gene testing

Test relatives, surveillance, only test at adulthood and gene variant problems

15

Do polymorphisms cause disease?

NO - the wrong message does