Dimples are inherited as an autosomal dominant trait A cleft

Dimples are inherited as an autosomal dominant trait. A cleft chin is inherited as an autosomal recessive trait. Red-green colorblindness is inherited as an X-linked recessive trait.

Clem has normal vision, dimples and a non-cleft chin, though his mother had a cleft chin and no dimples. Gwendolyn has no dimples, a cleft chin, and normal vision, though her father was colorblind. Gwendolyn thinks Clem’s dimples are adorable, and Clem is equally fond of Gwendolyn’s cleft chin, and both are enamored of the other’s excellent full-color vision. Obviously, they fall madly in love.

Clem and Gwendolyn immediately plan to have two children and hope that both children will get Clem’s dimples, Gwendolyn’s cleft chin, and normal vision. You are their genetic counselor. What are their chances that both children get the desired phenotypes? SHOW YOUR WORK!

Clem = DdCcXy

Gwen = DDccXXc

100% chance of dimples, 50% chance of cleft chin, 75% chance of normal vision, so . . . 1 x 1/2 x 3/4 x ?

Is this correct? what would it be multiplied by for both children to end up with these traits?

Solution

1. Dimples are autosomal dominant trait. Clem has dimples but his mother doesn\'t and Gwen does\'t. So thier children have 50% chnace to get dimples.

2. Cleft chin is a autosomal recessive trait Clem has no cleft chin but his mother does and Gwen does. So Clem is a carrier for cleft chin. So there is a 50% chance of getting cleft chin to their children.

3. Red- green colour blindness is a X- linked recesiive trait. Clem mother and he has normal vision. But Gwen father has so she is carrier for color blindness with normal vision. So their children has 25% chance to get colour blindness.

So above assumption was wrong.So multiply by 2 for both children, will get these traits.