Lecture 16: Gene - Function - Clinic

Question 1

What does gene identification allow for?

Answer 1

): the occurrence in members of a population of combinations of linked genes in non-random proportions

Question 2

What percent of mutation are only responsible for what percent of familial cancers?

Answer 2

16%
Account for 5-10% of all breast cancers

Question 3

In the USA what percent is a woman likely to get breast cancer?

Answer 3

12%

Question 4

What percent does the BRA1 or BRA2 gene increase the risk of breast cancer by?

Answer 4

85%

Question 5

Give 3 advantages of testing for the BRCA genes in women?

Answer 5

1) women may take preventative measures to help reduce risk of breast cancer

2) other family members may decide they wish to be tested for BRCA

3) women with breast cancer may have better responses to certain treatments that are specifically designed for BRAC positive patients

Question 6

Gove three disadvantages of testing for the BRCA genes in women?

Answer 6

1) women may have difficulty telling their family members

2) women who test positive for BRCA mutations may falsely believe they will never get breast cancer

3) positive tests may cause complications with life insurance

Question 7

Other than breast cancer, give three other diseases that presymptomatic testing can be used for:

Answer 7

1) Huntington’s

2) retinits pigmentosa

3) colon cancer

Question 8

What is the name of the new prenatal diagnostic technique used at week 10?

Answer 8

NIPD (non-invasive prenatal diagnosis)

Question 9

How does NIPD work?

Answer 9

placental DNA in the maternal serum is NGS genome sequenced to identify trisomies

Question 10

Give three types of prenatal diagnosis:

Answer 10

1) NIPD

2) chorionic villus sampling

3) aminocentesis

Question 11

What week would chorionic villus sampling take place?

Answer 11

11 weeks

Question 12

What week would amniocentesis take place?

Answer 12

17 weeks

Question 13

Which body oversees preimplantation diagnosis?

Answer 13

the Human Fertilisation and Embryology

Question 14

Describe how ‘saviour siblings’ can be created from preimplantation diagnosis:

Answer 14

human leukocyte antigens can be selected to match cord blood stem cells for siblings

Question 15

What is preimplantation genetic diagnosis?

Answer 15

allows detection of genetic abnormalities prior to implantation

Question 16

What is non-disclosure?

Answer 16

where a mother wants to know if her child will be affected by a genetic disease but does not want to know if she is at risk

Question 17

What is precision therapy?

Answer 17

a strategy that integrates molecular information with clinical data to select the best therapeutic intervention

Question 18

What is gene therapy?

Answer 18

the use of genetic material (DNA or RNA) as medicine

Question 19

When is gene therapy used?

Answer 19

often to replace mutated genes, silence overactive genes or provide our immune cells with the tools they need to recognise and kill cancer cells and infections

Question 20

What is the name of the rare inherited eye disorder associated with the RPE65 gene?

Answer 20

Leber’s congenital amaurosis

Question 21

True or false: Leber’s congenital amaurosis causes blindness

Answer 21

true

Question 22

Does Leber’s congenital amaurosis follow a dominant or recessive inheritance pattern?

Answer 22

recessive

Question 23

What gene is associated with Leber’s congenital amaurosis?

Answer 23

RPE65

Question 24

What does RPE65 gene produce?

Answer 24

protein involved in phototransduction

Question 25

Describe the gene therapy used to cure Leber’s congenital amaurosis:

Answer 25

a sub-retinal injection between photoreceptors and retinal pigment epithelium containing adeno-associated virus containing human RPE65 and human RPE65 promoters is given

Question 26

What is CRISPR?

Answer 26

editing a gene with a specifically designed synthetic guide molecule after cutting defective target DNA out of the strand

Question 27

What is pharmacogenetics?

Answer 27

the correlation between the effect of drugs and the genetic constitution of patients

Question 28

What are cytochrome P450 oxidases?

Answer 28

a family of enzymes found predominantly in the liver responsible for the metabolic elimination of most drugs and converting pro-drugs into their inactive forms

Question 29

Describe CYP2D6 as an example of pharmacogenetics:

Answer 29

Some people have very active CYP2D6 genes while others done and having poor CYP2D6 activity is associated with worse survival when using tamoxifen so now genetic testing for CYP2D6 polymorphisms are carried out privately

Question 30

What is the role of CYP2D6?

Answer 30

It is involved in the rate determining step in converting tamoxifen to its active metabolite endoxifen

Question 31

What is the name of the branch of preventative medicine where clients can be tested for multiple different genes associated with diseases?

Answer 31

Direct-To-Consumer testing