In a human population the proportion of individuals affected

In a human population, the proportion of individuals affected by a rare autosomal recessive disease is about 0.000064. Estimate the incidence of people who are normal carriers. (Assume a very good fit to the H-W model.)

Solution

Answer:

According to Hardy-weinberg model

   p+q= 1

p²+2pq+q²

Autosomal Recessive disease = 0.000064

q²= 0.000064

q = 0.008

As P +Q = 1

      p= 1-0.008

      p = 0.992

so, P= 0.992 and q= 0.008

p2= 0.992 x 0.992= 0.984 = 98%

2pq= 2 x 0.992 x 0.008 = 0.0158

q2= 0.008 x 0.008 = 0.000064

Incidence of people who are normal carriers are 98%