Question

1. 1a. The estimated mutation rate of CF is 6.7 x 10-7. What does this suggest about the likelihood of CF being maintained by mutation-selection balance?

2. 1b. Lyczak et al. (2002) found a positive correlation between the frequency of CF carriers and the incidence of typhoid fever across 11 European countries. Explain why CF may occur at higher frequency than expected by mutation-selection balance.

Answer 1

1a. The likelihood of CF risk is lower at 6.7×10^-7, because the mutation selection rate is very frequent, that would be at 0.02 which would be at 4×10^-4.

1b.CF occurs at a higher frequency due to the deficiency of arylsulphatase B,due to which CF occurs at a higher rate.