Cardiovascular Health Lecture 2.1 : Preventing Genetic Destiny

Question 1

What is a polygene?

Answer 1

A set of genes that collectively give a certain phenotype.

Question 2

What are the compnents of a phenotype? Give percentages.

Answer 2

• About 50% from genes.
• About 25% from a shared environment (diet, family and lifestyle influence).
• About 25% from individual environment.

Question 3

What are two genetic factors in genetic architecture? Explain both of them.

Answer 3

Rare coding sequences - less than 1/1000. Affects the coding sequence.
Non-coding variants - very common, most, if not all, people have them

Question 4

Give an example of the two genetic factors using high blood pressure as a parameter.

Answer 4

Rare coding variant - 5mmHg difference - 1/2000

Common -

Question 5

Do non-coding DNA sequences affect phenotype?

Answer 5

Yes, via epigenetics.

Question 6

What are changes in the body usually a consequence of?

Answer 6

Genes switching on and off at different times.

Question 7

Can high blood pressure be passed on?

Answer 7

Yes.

Question 8

Will individuals who inherit high blood pressure have high or low renin levels?

Answer 8

Low renin levels, as their parents do.

Question 9

What does having high blood pressure with high renin levels indicate?

Answer 9

Renal dysfunction.

Question 10

What do subjects with the highest blood pressure have?

Answer 10

High renin levels.

Question 11

What happens when the gene responsible for high blood pressure and high renin found in young mice is treated by interfering renin-angiotensin system? What happens when the treatment is stopped? What happens if they are later given renin?

Answer 11

Blood pressure goes down. Remains down even when treatment is stopped. Blood pressure returns when given renin.