What is a possible inheritance pattern for the pedigree shown here?
A) autosomal dominant
B) autosomal recessive
C) X-linked recessive
D) could be autosomal recessive or X-linked recessive
E) X-linked dominant

Question

What is a possible inheritance pattern for the pedigree shown here? 
A) autosomal dominant 
B) autosomal recessive 
C) X-linked recessive 
D) could be autosomal recessive or X-linked recessive 
E) X-linked dominant

Quizplus · Accepted Answer

The trait in the pedigree cannot be autosomal dominant because there is an individual with the trait who has two unaffected parents. Likewise, the trait cannot be X-linked dominant because the affected male on the bottom row would have to have a mother that exhibits the trait as well, since a male receives his X-chromosome from his mother. Thus, the trait is recessive, but both X-linked recessive and autosomal recessive are possible.

What Is a Possible Inheritance Pattern for the Pedigree Shown