Question

Lesch-nyhan syndrome is an x- linked recessive disorder that cause neurological damage in human beings. A survey of 500 males from a population revealed that 20 were affected with this disorder. What will be the frequency of the normal allele in the population?

Answer 1

Hello Dear,

● Answer -

Frequency of normal allele = 0.8

◆ Explaination -

Let p be frequency of dominant (normal) allele & q be frequency of recessive (defective) allele.

According to Hardy-Weinberg principle,

p² + 2pq + q² = 1

Given that affected people (homozygous recessive) are 20 in 500 observations.

q² = 20 / 500

q² = 0.04

q = 0.2

Putting this in eqn,

p² + 2pq + q² = 1

p² + 2p × 0.2 + 0.04 = 1

p = 0.8

Hence, frequency of normal (dominant) allele w.r.t. Lesch–Nyhan syndrome in given population is 0.8 .

Hope I was useful.

Answer 2

Hello Dear,

● Answer -

Frequency of normal allele = 0.8

◆ Explaination -

Let p be frequency of dominant (normal) allele & q be frequency of recessive (defective) allele.

According to Hardy-Weinberg principle,

p² + 2pq + q² = 1 ...(1)

Given that affected people (homozygous recessive) are 20 in 500 observations.

q² = 20 / 500

q² = 0.04

q = 0.2

Putting this in eqn,

p² + 2pq + q² = 1

p² + 2p × 0.2 + 0.04 = 1

p = 0.8

Hence, frequency of normal (dominant) allele w.r.t. Lesch–Nyhan syndrome in given population is 0.8 .

Hope I was useful.