Genetics

Question 1

describe somatic mosaicism

Answer 1

two genetically distinct populations fo cells within an individual, derived from post-zygotic mutations

Question 2

why do most variations in DNA as cells divide not matter

Answer 2

only around 2% of the genome is coding

Question 3

what does inactivation of a tumour suppressor cause?

Answer 3

inability to control cell growth

Question 4

how does inactivation of a tumour suppressor happen

Answer 4

Knudson’s two hit hypothesis

Question 5

most common form of cancer inheritance

Answer 5

multifactorial

Question 6

role of oncogenes

Answer 6

stimulate cell growth

Question 7

how can an oncogene be activated?

Answer 7

• duplication
• activation of promoter
• change in amino acid sequence

Question 8

driver mutations

Answer 8

determines cancer characteristics

Question 9

NGS

Answer 9

identify mutations and give genomic profile of cancer

Question 10

SNPs

Answer 10

show alterations in DNA sequence

Question 11

passenger

Answer 11

incidental mutations that happen because the genome is unstable

Question 12

what does a Philadelphia chromosome do?

Answer 12

switch oncogene on

Question 13

what inhibits the Philadelphia chromosome switching an oncogene on?

Answer 13

imatinib

Question 14

cancer risk

Answer 14

function of the genotype and environment

Question 15

cancer behaviour

Answer 15

function of somatic mutations

Question 16

cancer risk statistics

Answer 16

population
multifactorial (3%)
mutation (8%)

Question 17

how can high penetrance risk be modified?

Answer 17

screening early
hormonal manipulation
surgical intervention

Question 18

grade

Answer 18

what the cells look like

Question 19

stage

Answer 19

how far the cancer has spread

Question 20

karyotyping

Answer 20

whole genome sequenced to show large abnormalities

Question 21

FISH

Answer 21

fluorescence certain chromosomes, targeted

Question 22

MSI

Answer 22

Microsatellite instability

Question 23

what is microsatellite instability

Answer 23

condition of genetic hypermutability (predisposition to mutation) that results from impaired DNA mismatch repair