Case05 At risk for hemophilia

1. Review the four principles of sex-linked inheritance. Which individuals demonstrate that it affects more often in males than females?

Males: Terry, Greg, Bill

Females: Jenny

2. Which individuals represent the idea that the trait is not passed from father to son?

Henry doesn’t pass it to Richard

3. Which individuals represent the principle that the trait can “skip a generation” or more being transmitted through a series of asymptomatic female carriers.

What’s asymptomatic?

No one really shows this principle

4. Why are none of the males in the figure shown as carriers of hemolphilia?

Males can’t carry, they only express the normal or recessive gene.

Carrying implies you are heterozygous for the trait.

5. What is the probability that Marcy and Tom will have any child with hemophilia (either sex)

There’s a 50% chance Marcy is a Carrier

Of that 50% chance cross XHXh with XHY-

¼ XHXH normal female

¼ XHY- normal male

¼ XHXh carrier femal

¼ XHY- hemophilic male: ¼ of 50% is 12.5 %

6. Suppose Marcy is pregnant. She gets an amniocentesis. Its going to be a girl. Should she be worried that the girl will be a hemophiliac?

No see above: Marcy can only have normal or carrier females

Can Marcy have hemophilic Grandchildren?Yes if she is a carrier and passes it on to her

daughter.

7. Blood typing can help determine paternity. Suppose an unmarried woman gives birth, charges a certain man with being the father and sues for child support. Its on Maury Povich. He demands blood tests.

Woman: Type ABaby: Type APotential Father: Type BDoes this rule him out?No. He could be type IBiThat would mean the baby is type IAi