Zellweger syndrome is an inherited genetic condition affecting the nervous system and other bodily functions. Signs of the condition may be present from birth.

The condition may also be known as Zellweger spectrum disorder.

Zellweger syndrome can be mild, moderate, or severe. In infants, severe cases are often fatal, but those with mild symptoms may survive into adulthood.

Signs and symptoms range from atypical facial features to muscle weakness and organ dysfunction. In some people, the main feature involves developmental delays during childhood, after which vision and hearing problems develop when they are adults.

This article looks at why Zellweger syndrome happens, how it appears, and what to expect.

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Zellweger syndrome is known as a peroxisomal disorder because it affects the production and use of proteins called peroxins. These proteins are essential to many bodily functions, including nerve health and kidney function.

It is also a metabolic disorder because it affects the production and use of proteins and enzymes.

Zellweger syndrome is a rare genetic disorder involving a wide range of possible signs and symptoms. It affects around 1 in every 50,000 live births in the United States, and its effects can vary from mild to severe.

Symptoms result when a person is born with certain atypical genetic features. Issues with these genes mean the body has a decreased ability to produce myelin — which forms the protective cover on nerves — and to carry out other essential functions.

The symptoms of Zellweger syndrome can vary widely and range from mild to severe.

Symptoms in infants include:

These symptoms often worsen over time and may progress rapidly.

A person may also have atypical facial or physical features, such as:

  • a flattened face
  • a wide nasal bridge
  • a high forehead
  • widely spaced eyes
  • an atypically large space at the fontanelle, which is the area between the bones of the skull
  • other atypical skeletal features

As a child develops, other features may appear, such as:

The symptoms may be similar for adults and adolescents, but muscle control issues, developmental delays, and adrenal insufficiency may be more noticeable.

Zellweger syndrome results from changes in certain genes. It is an inherited condition where an infant inherits genes characterizing the condition from both biological parents.

The parents may not know they have these genes. If a person inherits one healthy copy and one altered copy of the gene, they are unlikely to develop symptoms. However, if both parents have copies relating to the condition, and an infant inherits one from each parent, they can develop Zellweger syndrome.

Experts have linked Zellweger syndrome to changes in at least 13 genes that the body needs to produce and manage a group of proteins called peroxins. Around 65% of those with the condition have changes in the gene known as PEX1.

Peroxins are essential in the formation of peroxisomes, which are cell structures that play a role in metabolism and nerve function.

A doctor may diagnose Zellweger syndrome through:

  • screening at birth
  • observing atypical signs and symptoms
  • blood tests, to assess levels of specific biochemicals in the body
  • skin tests in mild cases, as changes may not always show up in blood tests
  • genetic testing

People at risk of carrying the gene may have prenatal and genetic counseling to advise them on what to expect if they have children.

There is not yet any cure for Zellweger syndrome.

Doctors have previously tried the following, but research has not proven their effectiveness:

  • docosahexaenoic acid, which plays a role in the healthy development of the eyes, brain, and nerves
  • Lorenzo’s oil, which can help manage levels of certain very long-chain fatty acids
  • cholic acid, which helps the body absorb vitamin D and other fat-soluble vitamins

Currently, clinical trials are underway to search for an effective treatment.

Meanwhile, a team of health professionals can offer support to help a person and their loved ones have the best possible quality of life.

They may recommend:

Zellweger syndrome is a lifelong condition. Infants born with signs of the syndrome often do not survive beyond the first year.

The older a person is when symptoms appear, the more likely they are to survive into adulthood.

However, there is a high risk of these individuals developing liver disease and neurological symptoms, which can affect a person’s quality of life and, in some cases, their life expectancy.

Support for people with Zellweger syndrome and their loved ones

The following may be helpful for those with Zellweger syndrome and their families and loved ones:

Here are some answers to common questions about Zellweger syndrome.

What are the symptoms of Zellweger syndrome?

The effects of Zellweger syndrome vary widely and can affect the whole body.

Symptoms include muscle weakness, vision and hearing loss, seizures, and problems with key organs, such as the heart and liver. It may also lead to atypical facial features and developmental delays in children. The effects range from mild to severe.

Can people survive Zellweger syndrome?

This depends on how severe the condition is. Infants born with the severe form often do not survive beyond 1 year, but people with mild and moderate forms often survive into adulthood.

Zellweger syndrome is an inherited genetic condition that affects how the body produces and uses certain proteins known as peroxins. These proteins are essential for functions throughout the body.

The effects of Zellweger syndrome range from mild to severe and include weak muscle tone, vision and hearing loss, and problems with the liver and other organs.

There is currently no cure for Zellweger syndrome, but a range of interventions can support people living with this condition.