Question

Hemophilia is a recessive sex-linked disorder (Xh). A man with hemophilia and a female carrier are concerned about their daughter inheriting the disorder. Use a punnett square explain to these parents the probability (percent chance) that their daughter could have the disorder. ​

Answer 1

The chances of a hemophilic man and a female carrier having a that one of their daughters inherits the disease are 25%.

Step-by-step explanation:

Since hemophilia is a disease with a sex-linked recessive inheritance pattern —X chromosome— all males who acquire the altered gene will have hemophilia (
`X^(h)`Y), while a female should have both altered chromosomes (
`X^(h)`X) to manifest the disease.

If a hemophilic male and a female carrier of the hemophilia gene have children, the possibility of having a daughter with hemophilia can be seen by crossing.

• ♂
  `X^(h)`Y
• ♀
  `X^(h)`X

Alleles
`X^(h)` Y

`X^(h)`
`X^(h)`
`X^(h)`
`X^(h)`Y

X
`X^(h)`X XY

In the offspring, there are:

• Healthy sons 25%.
• Hemophilic sons 25%.
• Carrier daughters 25%.
• Hemophilic daughters 25%.

The hemophilic man and the carrier woman should know that they have a 25% chance of having a hemophilic daughter, or that 50% of their daughters may have the disease.