A certain human population is scored for the PrPc prion locu

A certain human population is scored for the PrPc prion locus and found to have the following genotype frequencies: MM = 0.16 MV = 0.80 VV = 0.04. What is the frequency of the M allele?

Solution

Solution:     Genotype frequency of MM (Homozygous dominant allele) = 0.16

                   Genotype frequency of MV (Heterozygous allele)   = 0.80

                   Genotype frequency of VV (Homozygous recessive) = 0.04

                 The frequency of the M allele is calculated by using of Hardy- Weinberg equation as :

f = p² + 2pq+ q² = 1 and p + q =1

p = frequency of domiant allele in the population

q = frequency of recessive allele in the population

f = p2+2pq+q2 =1

   0.16+2x0.16x0.04+0.04 =1

p +q =1

0.16+0.04 = 1

P( M allele) = 0.16 x 1/2 x 0.04 = 0.0032