Question

A girl of normal stature is born to two parents with achondroplasia who have very short stature, especially disproportionately short arms and legs. What is the probability (by Punnett Square analysis) that any pregnancy this girl eventually has will result in the birth of an infant with achondroplasia if her partner also has normal stature? (HINT: achondroplasia is an autosomal dominant trait)

Answer 1

Answer: 100% (4/4)
Explanation: Since the woman’s trait is dominant it will mask the normal stature in all their offspring. For example, A = achondroplasia trait, a = normal stature. It is very possible that the woman carries the trait and her offspring who may not possess it can pass it on to their offspring