Risk of Transmission of Disease Flashcards Preview

MCD- Genetics- Laz > Risk of Transmission of Disease > Flashcards

Flashcards in Risk of Transmission of Disease Deck (9):
1

State the differences between monogenic and complex diseases.

Monogenic diseases are rare, have a clear inheritance pattern and are not affected by environmental factors Complex diseases are the opposite

2

State the difference between mutations and polymorphisms.

Mutations are any changes in genetic material that are hereditary Polymorphisms are mutations which occur at >1% frequency in the population

3

State two different types of point mutations

Non-sense and mis-sense

4

State two types of frame shift mutations.

InDel

5

Give an example of an autosomal dominant disease and the mechanism of action.

Huntingdon’s Disease – mutations in the HTT gene on Chr 4, which codes for huntingtin. Mutation leads to production of a toxic protein that accumulates and forms clumps in organs. Causes cell death in the basal ganglia in the brain. It is caused by an unstable CAG repeat – the more repeats you have the more likely you are to get HD. Severity increases with time and age of onset decreases.

6

Give an example of an autosomal recessive disease and the mechanism of action

Cystic Fibrosis – caused by a mutation in the CFTR gene on Chr 7, which affects chloride ion function in epithelial cells. Gives rise to thick mucus.

7

Give an example of a mutation in the same gene causing two different conditions

Congenital absence of the vas deferens – caused by mutations in CFTR

8

Give an example of a X-linked recessive condition

Haemophilia A and B – A is caused by a mutation in the F8 gene on Chr X which encodes factor VIII.
B – caused by mutation in F9 gene which encodes factor IX

9

What are the general molecular mechanisms of the different types of genetic disease (autosomal dominant, autosomal recessive, co-dominant)?

Dominant – toxic product produced (treatment aims to neutralise toxic product)
Recessive – absence of functional protein (treatment aims to regain function)