Zellweger syndrome is a rare and severe genetic disorder that damages the white matter of the brain and affects how the body metabolizes substances. It is caused by defects in the PEX genes required for normal peroxisome formation and function. Diagnosis involves tests to check for high organic compound levels and liver biopsy to examine peroxisomes. Physical symptoms include distinctive facial features, eye abnormalities, loose skin, weakness and seizures. There is no cure and most infants do not survive past 6 months due to organ failure or other issues. Treatments are limited to symptom management.

2. What Is It?
Zellweger Syndrome is related to Peroxisome Biogenesis
Disorder (PBD), which is part of a larger group of diseases
called the leukodystrophies. These are inherited conditions
that damage the white matter of the brain and also affect
how the body metabolizes particular substances in the blood
and organ tissues. It is the most severe of the PBD’s.

3. Diagnosis
Prenatal diagnosis is achieved via CVS (chorionic villus
sampling), an invasive procedure done in early pregnancy
that removes a tiny piece of the placenta, and
amniocentesis. Determining the amount of peroxisomes via
a liver biopsy is considered an essential part of diagnosis.
Blood tests that indicate high levels of various organic
compounds in the blood can also confirm the diagnosis.

4. Causes
• Defects in any one of the 13 genes
• Termed PEX genes (PEX genes are required for
the normal formation and function of
peroxisomes)
• Dysfunctional lipid metabolism
• Defects of the bile acids and plasmalogens
• Lack in, or absence of, peroxisomes

5. Physical Symptoms
• Defects in the face, development, or eyes
• Up slanting eyes
• High forehead
• Skin folds along the person’s nasal borders of the
space between the upper and lower eyelids of their
eyes
• Loss of muscle tone/extreme weakness
• Seizure activity
• Jaundice

6. Internal Symptoms
• Enlarged liver
• Increased levels of copper and iron in the blood
• Inability to move
• Intellectual disability
• Gastrointestinal bleeding
• Prenatal growth failure
The liver on
the left is
normal.
The liver on
the right is
enlarged.

7. Treatments
There is no cure for Zellweger Syndrome, or a common
treatment. The metabolic and neurological symptoms of
this disease are formed during the fetal development.
Treatments are limited, and most are symptomatic and
supportive.
A is a normal brain. B is a brain with Zellweger Syndrome.

8. Prognosis
There is no real prognosis for Zellweger Syndrome. Most
infants do not survive the first 6 months of life, and usually
fall into respiratory distress, gastrointestinal bleeding, or
liver failure.

9. Bibliography
• "NINDS Zellweger Syndrome Information Page." Zellweger
Syndrome Information Page: National Institute of Neurological
Disorders and Stroke (NINDS). National Institute of Neurological
Disorders and Stroke, 27 Sept. 2011. Web. 17 Oct. 2012.
<http://www.ninds.nih.gov/disorders/zellweger/zellweger.htm>.
• Weiss, Thomas C. "Zellweger Syndrome - Facts and
Information." Disabled World. Disabled World, 13 Mar. 2012. Web.
17 Oct. 2012. <http://www.disabled-
world.com/disability/types/zellweger-syndrome.php>.
• Honor Society of Nursing. "How Is Zellweger Syndrome Diagnosed?"
Sharecare. Sharecare, n.d. Web. 22 Oct. 2012.
<http://www.sharecare.com/question/how-zellweger-syndrome-
diagnosed>.