Hunter syndrome is a rare genetic disorder in which large sugar molecules called glycosaminoglycans build up in body tissues. Hunter syndrome causes abnormalities in many organs, including the skeleton, heart, and respiratory system. In severe cases, this leads to death during the teenage years. Hunter syndrome is caused by a recessive gene on the X chromosome. If a woman who is normal (but had a father with the disease) marries a normal man, what are the chances of having a daughter affected by the disease?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Question

Quizplus · Accepted Answer

Hunter syndrome is an X-linked recessive disorder, meaning it is carried on the X chromosome. Since females have two X chromosomes, a daughter would need two copies of the affected gene to show symptoms of the disease. In this scenario, the mother is a carrier (her father had the disease, so she must have one affected X chromosome), but the father can only pass on a Y chromosome to daughters, making it impossible for a daughter to inherit the affected X chromosome from him. Therefore, daughters cannot be affected by the disease in this genetic cross.

Hunter Syndrome Is a Rare Genetic Disorder in Which Large