Retinoblastoma is a type of eye cancer that begins in the retina. This type of cancer most typically presents itself in childhood. There is a hereditary form of retinoblastoma that is inherited in an autosomal dominant fashion. Beyond the eye cancer itself, complications include an increased risk for the development of cancer in other parts of the body.
Cindy and Eric are contemplating having children and visited a genetic counselor. They are concerned because, while both Cindy and Eric are healthy, Eric's father and younger sister both developed retinoblastoma as children.
Based upon this information, the genetic counselor calculated the probability of a child of Cindy and Eric developing hereditary retinoblastoma.
What is this probability?