Answer to Question #165033 in Genetics for Fathima Ziana

Question

List the characteristics of dominant inheritance linked to the X chromosome.

Give 2 examples of diseases.

Describe the scheme when crossing

1) a sick woman (2 options !!!) and a healthy man.

2) a healthy woman and a sick man

Answer 1

Families with an X-linked dominant disorder often have both affected males and affected females in each generation. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons; fathers only pass X chromosomes to their daughters and Y chromosomes to their sons.

X-linked dominant disorders include Rett syndrome, the X-linked lissencephaly and double-cortex syndrome.

• 1.A woman passes on one or the other of her X chromosomes to each child. Therefore, a woman with an X-linked dominant disorder has a 50 percent chance of having an affected daughter or son with each pregnancy.
• 2.A man passes on his Y chromosome to all of his sons and his X chromosome to all of his daughters. Therefore, the sons of a man with an X-linked dominant disorder will not be affected, but all of his daughters will inherit the condition.