If retinoblastoma requires mutation in two copies of the RB gene, and familial cases inherit one such mutation, doesn't it seem unlikely that a second mutation would occur in a retinal cell at this specific gene? Yet 90 percent of those individuals who inherit one mutant RB gene develop a second mutation and retinoblastoma. Why does this occur with such a high frequency?

Question

Quizplus · Accepted Answer

The Answer of If retinoblastoma requires mutation in two copies of the RB gene, and familial cases inherit one such mutation, doesn't it seem unlikely that a second mutation would occur in a retinal cell at this specific gene? Yet 90 percent of those individuals who inherit one mutant RB gene develop a second mutation and retinoblastoma. Why does this occur with such a high frequency?

If Retinoblastoma Requires Mutation in Two Copies of the RB