Zellweger syndrome is caused by the absence of which cellular component?

• A. Peroxisomes
• B. Mitochondria
• C. Lysosomes
• D. Nucleus

Answer: (A)

Zellweger syndrome is a genetic disorder characterized by the absence of functional peroxisomes, which are essential organelles in the cell responsible for various metabolic functions, including the breakdown of fatty acids and the detoxification of hydrogen peroxide. In individuals with Zellweger syndrome, the deficiency in peroxisomes leads to the accumulation of very long-chain fatty acids and other toxic substances, resulting in severe neurological, hepatic, and developmental abnormalities.

Peroxisomes play a critical role in lipid metabolism and contribute to the production of plasmalogens, which are important for proper cellular function, especially in the brain and lungs. The absence of these organelles disrupts the normal metabolic processes, leading to the characteristic manifestations of the disease, such as hypotonia, seizures, and other systemic issues.

The other cellular components listed—mitochondria, lysosomes, and the nucleus—are involved in different cellular functions. Mitochondria are primarily responsible for energy production through oxidative phosphorylation, lysosomes are involved in waste degradation and recycling, and the nucleus contains genetic material and regulates gene expression. While dysfunctions in these components can lead to other disorders and syndromes, they are not the underlying cause of Zellweger syndrome. Thus, the correct