What is Zellweger syndrome?
Zellweger syndrome belongs to a group of diseases called peroxisome biogenesis disorders (PBD). The diseases are caused by defects in any one of the PEX genes that are required for the normal formation and function of peroxisomes.
Peroxisomes are cell structures that breakdown toxic substances and synthesize lipids (fatty acids, oils, and waxes) that are necessary for cell function. Peroxisomes are required for normal brain development and function and the formation of myelin, the whitish substance that coats nerve fibers. They also are required for normal eye, liver, kidney, and bone functions.
The PBDs are divided into two groups:
- Zellweger spectrum disorders
- Rhizomelic Chondrodysplasia Punctua spectrum
The Zellweger spectrum is comprised of three disorders that have considerable overlap of features:
- Zellweger syndrome (the most severe form)
- Neonatal adrenoleukodystrophy (NALD)
- Infantile Refsum disease (the least severe form)
Zellweger spectrum disorders result from dysfunctional lipid metabolism, including the over-accumulation of very long-chain fatty acids and phytanic acid, and defects of bile acids and plasmalogens--specialized lipids found in cell membranes and myelin sheaths of nerve fibers.
Symptoms of these disorders include:
- An enlarged liver
- Characteristic facial features such as a high forehead, underdeveloped eyebrow ridges, and wide-set eyes
- Neurological abnormalities such as cognitive impairment and seizures
Infants will Zellweger syndrome also lack muscle tone, sometimes to the point of being unable to move, and may not be able to suck or swallow. Some babies will be born with glaucoma, retinal degeneration, and impaired hearing. Jaundice and gastrointestinal bleeding also may occur.
There is no cure for Zellweger syndrome, nor is there a standard course of treatment. Most treatments are symptomatic and supportive.
How can I or my loved one help improve care for people with Zellweger syndrome?
Consider participating in a clinical trial so clinicians and scientists can learn more about Zellweger syndrome and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with Zellweger syndrome at Clinicaltrials.gov.
Where can I find more information about Zellweger syndrome?
Information about Zellweger syndrome may be available from the following organizations:
Child Neurology Foundation
Global Foundation for Peroxisomal Disorders