Infection 1

Question 1

What do twin studies in infection show?

Answer 1

Higher concordance in MZ (identical twins who share 100% of their genes) when compared to DZ (fraternal twins who share on average 50% of their genes) indicates a genetic influence on the disease studied

Question 2

What is the relationship between sickle cell anaemia and malaria?

Answer 2

Pts with HbS lack the Duffy antigen so P.vivax can’t enter

Therefore HbS carrier is protective against malaria

Question 3

What is the relationship between G6PD & thalassemia and malaria?

Answer 3

Make parasite-infected erthryocytes more susceptible to dying from oxidative stress

Question 4

How does P vivax cause disease in Duffy postive individual?

Answer 4

P vivax can only evade RBC that express DARC

Transcription factor GATA-1 activates DARC gene

Question 5

Why does P vivax fail to cause disease in Duffy negative individual?

Answer 5

Transcription factor GATA-1 is mutated DARC negative individuals

Question 6

Individuals found to be resistant HIV found to have a mutation in what gene.

Answer 6

homozygous for 32 bp deletion in the CCR5 gene

Question 7

What is maraviroc?

Answer 7

• chemokine receptor antagonist

- acts against HIV by interfering with the interaction between HIV and CCR5.