Which disease affects the level of ceruloplasmin?

The correct choice is Wilson's disease because it is a genetic disorder that affects copper metabolism in the body, leading to an accumulation of copper in various tissues. This condition has a direct impact on ceruloplasmin levels. Ceruloplasmin is a protein that carries copper in the bloodstream, and when copper accumulates due to Wilson's disease, ceruloplasmin production can be altered. In Wilson's disease, ceruloplasmin levels are often low because the body cannot effectively incorporate copper into the protein for transportation.

In contrast, the other conditions listed do not have a significant effect on ceruloplasmin levels in the same way. Addison's disease is an adrenocortical insufficiency that can affect various hormones and metabolic processes but does not directly alter ceruloplasmin. Pheochromocytoma is a type of tumor that affects adrenal gland function and usually leads to catecholamine overproduction, without a direct relation to ceruloplasmin. Cushing's syndrome is characterized by excess cortisol, affecting numerous metabolic functions, yet its relationship with ceruloplasmin is not causal. Thus, Wilson's disease is the most relevant condition concerning alterations in ceruloplasmin levels.