Question

What is the recurrence risk for the couple to have another child with achondroplasia?

(A) 50%
(B) 25%
(C) 3%-5%
(D) 1%-2%
(E) 0%

Answer 1

The recurrence risk for having another child with achondroplasia when one parent is affected by the condition and the other is not is 50%, due to the autosomal dominant pattern of inheritance.

Step-by-step explanation:

The recurrence risk for a couple to have another child with achondroplasia is 50%. Achondroplasia is an autosomal dominant condition, meaning that only one copy of the altered gene in each cell is sufficient for a person to be affected by the disorder. If one parent has achondroplasia (heterozygous for the gene) and the other parent does not, each child has a 50% chance of inheriting the affected gene and displaying the condition. The dominant nature of the gene assures that each child has an independent 50% risk of being affected, no matter how many children the couple has.