Question 3

Hemochromatosis is a recessive genetic disease, but the expression differs in individuals.

Hereditary hemochromatosis is primarily caused by inheriting two copies of a mutated gene, which indicates a recessive pattern of inheritance. The variability in symptoms among individuals who inherit the mutations also supports this statement.

A) Hemochromatosis is a dominant genetic disease caused by a single mutation.

This statement is incorrect because hereditary hemochromatosis is not a dominant genetic disease; it requires two copies of the mutated gene for the disease to manifest. Additionally, while the C282Y mutation is common, multiple mutations can cause the disease, contradicting the claim of a "single mutation."

B) Hemochromatosis is a recessive genetic disease, but is caused by a lack of iron.

This option incorrectly identifies the cause of hemochromatosis. The disease is characterized by excessive iron absorption, not a lack of iron. While it is true that hemochromatosis is recessive, the cause stated here is fundamentally flawed.

C) Hemochromatosis is a recessive genetic disease, but the expression differs in individuals.

This statement accurately summarizes the information provided. It acknowledges the recessive nature of the disease, requiring two mutated copies for manifestation, while also noting the variability in symptom expression among individuals with the mutations.

D) Hemochromatosis is a dominant genetic disease that can be caused by several different alleles.

This statement is incorrect as it misclassifies hemochromatosis as a dominant genetic disorder. The disease requires the presence of two mutated alleles, and while multiple mutations may exist, the dominant categorization is not applicable.

Conclusion

The correct answer, C, effectively captures the recessive nature of hemochromatosis and highlights the variability in symptom expression among affected individuals. Options A, B, and D fail to accurately represent the genetic basis and the clinical variability of the disease, making them incorrect. Thus, option C stands as the most comprehensive summary of the information presented.