Chapter 8: Hereditary Risk

Question 1

Caretaker Genes

Answer 1

ATM
BLM
BRCA1 / BRCA2
XPA

Question 2

Gain of Function Genes

Answer 2

RET

Question 3

Familial Adenomatosis Polyposis (APC) Gene

Answer 3

Dominant
Colon Cancer
Gatekeeper

Question 4

Familial Retinoblastoma (RB) Gene

Answer 4

Dominant
Retinoblastoma/Osteosarcoma
Gatekeeper

Question 5

Li-Fraumeni syndrome (p53) Gene

Answer 5

Dominant
Various cancers
Gatekeeper

Question 6

Ataxia Telangiectasia (ATM) Gene

Answer 6

Recessive
Lymphoma
Caretaker

Question 7

Bloom Syndrome (BLM) Gene

Answer 7

Recessive
Multiple Cancers
Caretaker

Question 8

Familial Breast Cancer (BRCA) Genes

Answer 8

Dominant
Breast/Ovary
Caretaker

Question 9

Xeroderma Pigmentosum (XPA) Gene

Answer 9

Recessive
Skin
Caretaker

Question 10

Multiple Endocrine Neoplasia (RET) Gene

Answer 10

Dominant
Thyroid
Gain of Function

Question 11

Complete Penetrance

Answer 11

If inherited mutation is in a critical tumor suppressor gene, probability of developing cancer is 100%

Question 12

Familial Cancers

Answer 12

Inherited

Question 13

Penetrance of Gene

Answer 13

% of individuals with gene mutation that develop cancer

Question 14

Incomplete Pentrance

Answer 14

Mutation in critical gene is inherited BUT ONLY 80-90% will develop cancer

Question 15

RB gene

Answer 15

Tumor suppressor gene
Absence leads to cancer
Recessive
Two hit model

Question 16

Retinoblastoma

Answer 16

Cancer of retinal nerve in children; can move along optic nerve to brain

Question 17

Hereditary Retinoblastoma

Answer 17

Both eyes affected
1/3 cases
Heterozygous for mutation

Question 18

Sporadic Retinoblastoma

Answer 18

One eye affected

2/3 of cases

Question 19

RB Gene Mechanism

Answer 19

Acts like Mendelian dominant gene on chromosome 13

Question 20

Normal function of RB gene (un-Phosphorylated )

Answer 20

Regulate cell division

Stops cells before S Phase (Restriction point) gene

Question 21

Phosphorylated RB gene

Answer 21

Cells continue into S phase

Question 22

Cdk-cyclins

Answer 22

Add phosphate to RB from birth to age 6

Question 23

Two Hit Model

Answer 23

Mutation or Deletion are required

Single hit only disrupts one RB gene copy

Question 24

In the retinoblastoma cell, what action is needed to transform the cell?

Answer 24

The absence of the protein is necessary

Question 25

APC gene

Answer 25

Tumor suppressor gene

Two hit model

Question 26

E-6 Viral Protein

Answer 26

Binds to p-53 gene in HPV

Question 27

Tumor suppressor gene

Answer 27

Gatekeeper Function to stop cell proliferation

Question 28

DNA repair enzyme

Answer 28

Caretaker function to repair DNA mistakes

Question 29

Gain of function mutation

Answer 29

Oncogene protein is always active as a receptor on endocrine cells

Question 30

Xeroderma Pigmentosum

Answer 30

Skin cancer caused by inherited defect in excision repair enzymes
“Camp Sundown”

Question 31

Excision repair

Answer 31

Seven genes designated XPA - XPG code for required repair enzymes

Question 32

XPV codes for

Answer 32

DNA polymerase for translesional repair of pyramidine diners

Question 33

Mismatch repair

Answer 33

Repair that occurs during DNA replication

Question 34

Inherited risk of breast cancer

Answer 34

Only 10% of all breast cancers show inheritance

Question 35

Inheritance of mutated BRCA1 & BRCA2

Answer 35

40-80% risk breast cancer

15-65% risk ovarian cancer

Question 36

Ataxia Telangiectasia

Answer 36

Dilation of capillaries and lack of coordination

40% risk of cancer

Question 37

ATM Gene Function

Answer 37

Detect DNA damage (by radiation) and sending signal to p-53

Question 38

BLM Gene Function

Answer 38

Codes for DNA helicase to unwind DNA in repair

Question 39

Primary immune deficiencies

Answer 39

Lack of thymus, etc.

Question 40

Induced Immune Deficiencies

Answer 40

HIV

Question 41

Immune deficiency

Answer 41

Mostly leads to lymphomas and leukemias often by EBV

Question 42

Gatekeeper Genes

Answer 42

APC
RB
p53