Zellweger Syndrome Symptoms and Prognosis

Zellweger syndrome is a rare, inherited metabolic disorder that affects peroxisomes, organelles found in almost all body cells. Peroxisomes are responsible for many important cell processes, including energy metabolism, which means that Zellweger syndrome can severely impact the body.

Learn about the Zellweger spectrum disorders and find out how Zellweger syndrome affects the body, how it is diagnosed and treated, and what genetic counseling can offer.

Zellweger Spectrum Disorders

Zellweger syndrome, sometimes called cerebrohepatorenal syndrome, is the most severe of a group of disorders called Zellweger spectrum disorders. While the disorders on the spectrum were once thought to be separate entities, they are now classified as different variants of one disease process.

The Zellweger spectrum disorders include:

• Infantile refsum disease (least severe form)
• Neonatal adrenoleukodystrophy
• Zellweger syndrome (most severe form)

The disorders share many symptoms, but not all individuals will have all of the same symptoms or side effects depending on where they fall on the spectrum.

What Are the Symptoms of Zellweger syndrome?

Zellweger syndrome is estimated to occur in one of every 50,000 people. Both males and females can be born with this condition. It affects many parts of the body, including:

• Head and Face: Enlarged head; high forehead; large anterior fontanelle ("soft spot"); malformed earlobes; flat-looking face
• Brain and Nervous System: Abnormal brain development leading to seizures; hearing and vision impairment; severe mental retardation and developmental delay; diminished or absent reflexes
• Liver: Enlarged liver with impaired function; jaundice
• Kidneys: Renal cysts; hydronephrosis
• Muscles and Bones: Very low muscle tone (hypotonia); bone defects in the hands, legs, and feet

How Is Zellweger Syndrome Diagnosed?

The distinctive shape of the head and face of the infant born with Zellweger syndrome provides a clue to the diagnosis.

Zellweger syndrome causes the buildup of very long-chain fatty acids (VLCFA), so a test for VLCFA can help confirm the diagnosis. This and other highly specialized biochemical and genetic tests can be done at certain testing centers.

Rare diseases are difficult to diagnose. Having a medical team that communicates can help you get a diagnosis more quickly and improve care.

Treatment for Zellweger Syndrome

Despite the progress research has made in understanding Zellweger syndrome, no cure yet exists. Medical care focuses on treating the symptoms present, such as liver dysfunction and seizures. Changing the amount of VLCFA in the diet has not been shown to be an effective treatment.

In addition, physical, occupational, and speech therapy can assist with feeding and comfort issues.

The life expectancy for Zellweger syndrome varies depending on how severe the disease is. Children with severe Zellweger syndrome usually do not live beyond their first year of life. People with an intermediate form can survive into childhood, and those with a mild form may reach adulthood.

Early Detection Through Genetic Counseling

Early detection of Zellweger syndrome and other Zellweger spectrum disorders is possible through genetic testing.

Zellweger syndrome is inherited in an autosomal recessive manner, meaning that children develop it if both parents are carriers of the defective gene. If this is the case, each future child has a 25% chance of being born with Zellweger syndrome. Genetic counselors can help talk you through your risk.

Summary

Zellweger syndrome is a very rare metabolic disorder. Zellweger spectrum disorders range from mild to severe. People born with the disorder may have abnormal features of the head and face, along with nervous system, kidney, liver, muscle, and bone symptoms.

There is no cure for Zellweger syndrome, but medical care can help alleviate symptoms. Genetic testing can be used to detect Zellweger syndrome early. Talk to your healthcare provider if you have concerns about Zellweger syndrome.