Deafness is caused by recessive mutations in any one of at least five genes. Two deaf individuals have nine children, all of whom have normal hearing. Which of the following can you conclude?
A) The mutations are codominant to the normal allele.
B) The parents have the same mutated protein involved in inner ear development.
C) The parents have mutations in different genes.
D) The mutations are incompletely dominant to the normal allele.
E) The parents have mutations in the same gene.

Question

Quizplus · Accepted Answer

Since all nine children have normal hearing, it suggests that each parent carries mutations in different genes responsible for hearing. In this scenario, each child would inherit one normal allele from each parent for each of the genes involved, thus not exhibiting deafness. This is consistent with the idea that the parents have mutations in different genes, allowing for the possibility of producing offspring with normal hearing when those different genes complement each other.

Deafness Is Caused by Recessive Mutations in Any One of at Least