The Disease Most Closely Associated with Cytoplasmic Granule Fusion

Which disease is most closely associated with cytoplasmic granule fusion?

a) Chediak-Higashi syndrome
b) Chronic granulomatous disease
c) Gaucher disease
d) Niemann-Pick disease

Answer:

Chediak-Higashi syndrome is most closely associated with cytoplasmic granule fusion.

The disease most closely associated with cytoplasmic granule fusion is Chediak-Higashi syndrome. In Chediak-Higashi syndrome, there is a defect in the lysosomal trafficking regulatory protein, which leads to cytoplasmic granule fusion within phagocytes. This results in large lysosomal granules in leukocytes and impairs the ability of these cells to kill bacteria, thus affecting the immune system.

As a comparison, Chronic granulomatous disease involves defects in the NADPH oxidase system, resulting in the inability to produce superoxide radicals. While this is crucial for killing ingested bacteria by phagocytes, it does not typically involve granule fusion.