A young woman and her husband want to start a family. The young woman explains to the nurse that she had a retinoblastoma as a child

Question

The woman and her husband are concerned about the chances of their son or daughter developing a retinoblastoma. What is important for the nurse to explain to the couple?
A) Retinoblastoma is an autosomal recessive inheritance in which each parent carries the gene mutation.
B) Retinoblastoma is an X-linked inheritance and all males inherit an X chromosome from their mothers.
C) Retinoblastoma is an autosomal dominant inheritance that has incomplete penetrance and can skip a generation.
D) Retinoblastoma is a pattern that is more horizontal than vertical; relatives of a single generation tend to have the condition.

Answer 1

Ans: C
Feedback: Retinoblastoma is an autosomal dominant inheritance that has incomplete penetrance, and the gene appears to skip a generation, thus leading to errors in interpreting family history and in genetic counseling. Autosomal recessive conditions have a pattern that is more horizontal than vertical; relatives of a single generation tend to have the condition. Genetic conditions inherited in an autosomal recessive pattern are frequently seen among particular ethnic groups and usually occur more often in children of parents who are related by blood, such as first cousins. X-linked conditions may be inherited in recessive or dominant patterns. In both, the gene mutation is located on the X chromosome.