Question

The inheritance of a skin condition in humansConsider the following family history:Bob has a genetic condition that affects his skin.Bob’s wife, Eleanor, has normal skin. No one in Eleanor’s family has ever had the skin condition.Bob and Eleanor have a large family. Of their eleven children, all six of their sons have normal skin, but all five of their daughters have the same skin condition as Bob.Based on Bob and Eleanor’s family history, what inheritance pattern does the skin condition most likely follow?a. X-linked dominantb. X-linked recessivec. Y-linkedd. Autosomal recessivee. Autosomal dominant

Answer 1

The correct answer would be X-linked dominant.

X-linked dominant inheritance is a type of inheritance in which a dominant gene is carried on the X chromosome.

In this type of inheritance, if a father is diseased and mother is unaffected, then all the daughters would carry the disease as daughters get an X chromosome from their father.

No son would be diseased as they only get a Y chromosome instead of the X chromosome from father.

When the mother is affected (heterozygous, that is, only one X chromosome carries dominant allele) and father is unaffected, then half of the sons and half of the daughters would carry the disease as mother passes X chromosome to both the son and daughter.