Albinism is a rare recessive autosomal disease that results

Albinism is a rare recessive autosomal disease that results in unpigmented skin, hair, and eyes. About 1 in 22, 500 people in the US is born with albinism. Assuming the US population is in HW equilibrium, what is the expected number of carriers per 10,000 people?

Solution

Answer :

% of albinism in the US population = (1/22,500) x 100 =0.004%

Hardy weinberg equation

p+q=1

Where

p=dominant allele

q=recessive allele

q=0.00004

p=1-0.00004=0.9996

p^2 +2pq+q^2=1

p^2 = number of normal individuals

q^2=number of albinism individuals

2pq=number of Carrier individuals

p^2=0.99x 0.99 = 0.98

q^2 = 0.00004 x 0.00004 =1.6 x 10^-9

2pq= 2 x 0.99 x 0.00004 = 7.9 x 10^-5

Among 10000 individuals

98% are p^2, that means 10000 x 0.98 =9800 are normal individuals

  (2) 1000 x 1.6 x 10-9 = 1.6 x 10^-6 are albino

  (3) 1000 x 7.9 x 10-5 =7.9 x 10^-2 are carrier individuals