Final answer:
The correct understanding of the inheritance of Huntington's disease is that there is a 50% chance each offspring will inherit the gene if one parent is affected, as it is an autosomal dominant disorder. Symptoms typically emerge in middle age, potentially after having children, allowing for the gene to be passed on. The correct option is B) "She could only have gotten the disease from both of us."
Step-by-step explanation:
The genetic aspects of Huntington's disease can be misunderstood, so it's important to clarify with correct information. The correct statement that demonstrates a good understanding of how Huntington's disease is inherited is: "If she has children, she'll pass the gene on to her kids."
This statement is accurate as Huntington's disease is an autosomal dominant disorder which means that if a parent has the disease, there is a 50% chance of passing the affected gene on to each child. A heterozygous individual (Hh) for the Huntington allele will develop the disease, typically in middle age, which may be after they have had children. This means the faulty gene can be transmitted to the next generation before the onset of symptoms.
It is not necessary for the gene to come from both parents, and the lifespan of an affected individual does not correlate with which parent passed down the gene. Genetic testing is available and can determine if a person carries the gene for Huntington's disease, thus statement D is not a demonstration of understanding the teaching as it suggests doubt in a confirmed diagnosis.