Zellweger syndrome is also known as cerebrohepatorenal syndrome is a rare, congenital disorder, characterized by the reduction or absence of peroxisomes in the cells of the
liver, kidneys, and brain. It is a type of
peroxisomal disorder. Peroxisomal disorders are a group of genetically heterogeneous metabolic diseases that share dysfunction of peroxisomes. Zellweger syndrome is the most severe form of peroxisome biogenesis disorders. Other peroxisome biogenesis disorders are Infantile Refsum disease, neonatal
adrenoleukodystrophy and rhizomelic chondrodysplasia.
Of all the above mentioned peroxisomal disorders infantile Refsum disease is the least severe form of the disease. The disorder is known to be X linked disorder and has a genetic basis. It is a rare disorder and no treatment is available for it. As it is the most severe form of the disease it results in death within the first year of the birth.
Functions of Peroxisomes
Peroxisomes are found in all cells, they are ubiquitous. Their functions are very important for the human body as they play important or vital role in metabolism. There functions include –
- Beta-oxidation of fatty acids
- Biosynthesis of ether phospholipids which includes Plasmalogen and Plasma Activating Factor (PAF)
- Biosynthesis of cholesterol and isoprenoids
- Detoxification of glycolate to glycine
- Oxidation of L-pipecolic acid
Signs and Symptoms
- Enlarged Liver (Hepatomegaly)
- High Forehead
- Underdeveloped eyebrow ridges and other facial deformities
- Deformed Ear Lobes
- Mental Retardation
- Seizures
- Decreased Muscle Tone
- Patient may be unable to move, suck or swallow
- Glaucoma
- Retinal Degeneration
- Impaired Hearing
- Jaundice
- Gastrointestinal Bleeding
Diagnosis and Investigations
- Blood tests can be done to check copper and Iron levels which are substantially increased in the disease
- There is also a deposition of copper and iron in the various tissues of the body
- Due to the impaired metabolism of the Very Long Chain Fatty Acids (VLFCA), there is abnormal accumulation of these in the various parts of the body. This is the hallmark of the disease.