A neonate has severe hypotonia, seizures, widely open anterior fontanelle, prominent forehead, flat nasal bridge, and hepatomegaly. Cranial ultrasound shows periventricular cysts. Plasma very long chain fatty acids are elevated. Which organelle is primarily affected?
- A Lysosome
- B Mitochondrion
- C Peroxisome ✓
- D Golgi apparatus
Correct answer: C. Peroxisome
Explanation
This describes Zellweger syndrome (cerebrohepatorenal syndrome), a peroxisom biogenesis disorder. The severe hypotonia, characteristic facies, hepatomegaly, seizures, periventricular cysts, and elevated very long chain fatty acids are diagnostic. Peroxisomes are absent or dysfunctional. Lysosomal disorders include mucopolysaccharidoses. Mitochondrial disorders show lactic acidosis. Golgi apparatus defects cause congenital disorders of glycosylation.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.