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 how Zellweger syndrome affects the body, plus treatment and genetic counseling options.

Zellweger 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 no classified as different variants of one disease process. The Zellweger spectrum disorders include:

• Cerebrohepatorenal syndrome
• Hyperpipecolic acidemia
• Infantile Refsum disease
• Neonatal adrenoleukodystrophy
• Zellweger syndrome

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.

Zellweger syndrome is estimated to occur in 1 of every 50,000 to 100,000 births. 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

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.

Despite the progress research has made in understanding Zellweger syndrome, no cure yet exists, and infants born with the disorder usually die within the first year of life. 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.

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 percent chance of being born with Zellweger syndrome. Genetic counselors can help talk you through your risk.