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

Multiple Choice

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.