Question

A married couple comes to the physician for routine prenatal counseling. The husband is 120 cm (3 ft 11 in) tall with disproportionately short upper and lower extremities a large head, and a prominent forehead. He is unable to provide a biological family history as he was adopted. His spouse is of average height with normal constitutional features, and her family history is insignificant. They are concerned about their unborn child's height. Which of the following is the best response to their concerns?

A. The condition is not inheritable
B. The risk depends on the child's gender
C. The risk depends on the mother's carrier status
D. The risk for the child to be short is about 25%
E. The risk for the child to be short is about 50%

Answer 1

The couple should consult a genetic counselor to address their concerns about their unborn child's height because the husband's physical features may indicate achondroplasia, a form of dwarfism caused by a dominant mutation.

Step-by-step explanation:

The concern of the married couple about their unborn child's height can be addressed with genetic counseling. Since the husband has disproportionately short extremities and a large head, this may indicate achondroplasia, which is a form of dwarfism caused by a dominant mutation. Although the husband's biological family history is unknown due to adoption, the mutation can be passed from one generation to the next. Therefore, the best response to their concerns is that there is a risk for the child to be short, but the exact percentage cannot be determined without further genetic testing and counseling.