Zellweger syndrome

Zellweger syndrome is a rare, congenital disorder (present at birth), characterized by the reduction or absence of peroxisomes (cell structures that rid the body of toxic substances) in the cells of the liver, kidneys, and brain.

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Causes

It is characterized by an individual's inability to beta-oxidize very-long chain fatty acids in the peroxisomes of the cell, due to a genetic disorder in one of the several genes involved with peroxisome biogenesis.

Several peroxins are associated with Zellweger syndrome, including 1, 2, 3, 5, 6, 12, 14, and 26.^[1]

Family

The disorder is one of three peroxisome biogenesis disorders which are also known as the Zellweger spectrum. The other two diseases are neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD)^[2]

Very long chain fatty acids are generally found in the central nervous system (brain and spinal cord) and the peroxisomes of these cells can not import the necessary degrative proteins for B-oxidation to occur.

Zellweger syndrome is one of a group of genetic disorders called peroxisomal diseases that affect brain development and the growth of the myelin sheath, the fatty covering—which acts as an insulator—on nerve fibers in the brain.

Eponym

Named after Hans Zellweger, a former professor of Pediatrics and Genetics at the University of Iowa who did research into the disease.^[3]

Presentation

The most common features of Zellweger syndrome include an enlarged liver, high levels of iron and copper in the blood stream, and vision disturbances. Some affected infants may show prenatal growth failure. Symptoms at birth may include a lack of muscle tone, an inability to move and glaucoma. Other symptoms may include unusual facial characteristics, mental retardation, seizures, and an inability to suck and/or swallow. Jaundice and gastrointestinal bleeding may also occur.

Prognosis

There is no cure for Zellweger syndrome, nor is there a standard course of treatment. Infections should be guarded against to prevent such complications as pneumonia and respiratory distress. Other treatment is symptomatic and supportive. The prognosis for individuals with Zellweger syndrome is poor. Death usually occurs by 6 months of age, and may be caused by respiratory distress, gastrointestinal bleeding, or liver failure.

References

1. ^ OMIM - ZELLWEGER SYNDROME; ZS. Retrieved on 2007-07-11.
2. ^ http://www.genetests.org/query?dz=pbd
3. ^ synd/1670 at Who Named It

• Based on http://www.ninds.nih.gov/disorders/zellweger/zellweger.htm