Genetics- Genetic Testing

Question 1

What are the potential scenarios for genetic testing?

Answer 1

Diagnostic
Predictive
Carrier

Question 2

What happens in diagnostic testing?

Answer 2

Testing a foetus or person for suspected condition

Question 3

How is a foetus tested?

Answer 3

Amniocentesis

Example of antenatal testing for Down’s syndrome

Question 4

What happens in predictive testing?

Answer 4

Testing person for specific gene mutation that has future implications

e.g. BRCA1 breast cancer gene
Huntington’s gene

Question 5

What other scenarios can genetic testing be used for?

Answer 5

Genealogical testing
Forensic testing
Paternity testing

Question 6

When there are ethical issues what must be given to patients?

Answer 6

Genetic counselling before testing

Question 7

What is Karyotyping and what is it useful for?

Answer 7

Looking at the number of chromosomes, size and structure

Diagnosing Down’s syndrome and Turner syndrome

Question 8

What is Microarray testing?

Answer 8

Enzymes break up genetic material

Different genes have different molecular weights

Genetic material applied to plate that separates molecules into different locations based on weights

Used to see what genes a person expresses

Question 9

What is microarray testing used for?

Answer 9

• Screening for chromosomal abnormalities
• Looking for mutations in cancer cells
• Research for matching genes with phenotypes

Question 10

How is specific gene testing done?

Answer 10

Splitting two strands of DNA and adding gene probe

Gene probe is single stranded DNA that contains complementary genetic code for a specific gene to be tested for

If gene probe matches the DNA they stick together indicating the patient has the particular gene

Question 11

What is DNA sequencing for?

Answer 11

Research only, no role in routine clinical practise