Hi guys,

I was hoping somebody might be able to help me with this question.

The information I am given:

Gamma1 = the risk of disease for people with the AG genotype compared to the risk of people with GG genotype.

Gamma2 = the risk of disease for people with the AA genotype compared with the risk of people with the GG genotype.

Use Bayes' theorem to show that:

Gamma1 = {P(AG|affected) P(GG)} / {P(GG|affected) P(AG)}

I really have no idea how to derive this from the normal Bayes' theorem:

P(A|B) = P(B|A) P(A) / P(B)

I also have to derive a corresponding equation for gamma2. Any ideas... anyone? lol.

In my thinking, A and B are two separate events, but affected is also an event, surely making an event C, which doesn't seem to be present in Bayes' theorem?

Any help is much appreciated. Thanks.