W6: Cancer Genetics

Question 1

inherited (germline) vs. acquired (somatic) mutations - how do their testings differ?

Answer 1

inherited: DNA of blood cell
acquired: biopsy of tumor

Question 2

Heritable cancer risk comes from inherited mutations in

__

Answer 2

tumor suppressor genes

Question 3

Knudson Hypothesis / Vogelstein Hypothesis is the “second-hit” hypothesis

Answer 3

Knudson

Question 4

Knudson Hypothesis states that __ is often required to produce malignant phenotype

Answer 4

“Second hit”

Question 5

Vogelstein Hypothesis states that for sporadic cancers, mutations are __ and __

Answer 5

gradually accrued, successively acquired

Question 6

3 mechanisms second hit can come about

Answer 6

1) deletion of opposite allele (most often)
2) point mutation
3) epigenetics

Question 7

Define LOH

Answer 7

Loss of heterozygosity - deletion of opposite allele

Question 8

How do you detect LOH?

Answer 8

Loss of heterozygosity detected by STR (short tandem repeat) polymorphism

Question 9

The cancer predisposition trait is inherited in an autosomal __ manner, but within the individual cell, the tumor suppressor genes act in a “__” manner, in that both alleles need to be inactivated for malignant transformation to occur.

What is cancer disposition trait?

Answer 9

dominant

recessive

cancer disposition trait is state of having one inherited allele with inactivated tumor suppressor

Question 10

Rb1; name of disease

Answer 10

tumor suppressor gene; Retinoblastoma

Question 11

p53; name of disease

Answer 11

tumor supressor gene; Li-Fraumeni syndrome (aka SBLA)

Question 12

Condition with 1000s of colonic polyp

Answer 12

FAP (familial adenomatous polyosis)

Question 13

Li-Fraumeni Syndrome aka

Answer 13

SBLA - sarcoma, breast, leukemia, adrenal gland;

p53 tumor suppressor gene