Question

In Zellweger syndrome, there is accumulation of which type of fatty acids?

• A. Accumulation of long fatty acids
• B. Accumulation of short chain fatty acids
• C. Accumulation of very long chain fatty acids
• D. Accumulation of medium chain fatty acids

Hint:

Peroxisomes handle the chains too long for mitochondria.

Answer 1

The Correct Option is C

Step 1: Zellweger syndrome (cerebrohepatorenal syndrome) is a rare inborn error caused by the absence of functional peroxisomes in all tissues, leading to defective peroxisomal fatty acid oxidation.

Step 2: Peroxisomes are the site where very long chain fatty acids (VLCFA, carbon chain length greater than 22) undergo the initial rounds of beta-oxidation before being shortened and handed over to mitochondria. Without peroxisomes this step fails.

Step 3: As a result, very long chain fatty acids are not oxidised and accumulate in tissues, especially the brain, liver, kidney and muscle, usually causing death by about six years of age. Hence option 3 is correct.

Step 4: Short, medium and ordinary long chain fatty acids are handled mainly by mitochondrial beta-oxidation, which is intact here, so options 1, 2 and 4 are wrong.