A genetic condition that often runs in families, passed from biological parents to their children, and causes cellular function problems is called Zellweger syndrome (ZS). It often causes serious health problems after birth. These include problems with the kidneys, brain, and liver, difficulty feeding, movement issues, and others. Unfortunately, it is not possible to cure this condition. As a result, infants usually do not live more than the first year of life.
Furthermore, this is the most severe condition of the 4 disorders in the Zellweger spectrum. Babies with this syndrome usually experience problems with nerves and metabolism right after birth. Sometimes, this syndrome is called cerebrohepatorenal syndrome. In most cases, this condition leads to death.
Zellweger Spectrum Disorders
These disorders are also known as peroxisomal biogenesis disorders because they affect the peroxisomes. However, peroxisomes are a part of cells that are vital for multiple functions in the body. Check below for other Zellweger spectrum disorders (ZSDs):
- Heimler syndrome – When a person develops this condition, he/she usually experience deafness (hearing loss) and tooth problems in late infancy or early childhood.
- Infantile Refsum disease – In such cases, babies experience muscle movement problems and delays in development.
- Neonatal adrenoleukodystrophy – This type of ZSD often causes problems with the brain, spine, and muscles. Sometimes, infants with neonatal adrenoleukodystrophy may experience deafness or blindness (vision loss).
This genetic disorder happens quite rarely. It affects about 1 in 50,000 to 1 in 75,000 babies.
Symptoms
The symptoms often appear right after birth and may include the following ones. Babies with Zellweger syndrome may have facial abnormalities. For example:
- Broad nose bridge
- Flattened face
- High forehead
- Epicanthal folds
- Wide-set eyes
- Underdeveloped eyebrow ridges
However, people with this syndrome may also experience other symptoms. Check some examples below:
- Seizures
- Problems with muscles and movement
- Jaundice (yellowing of the skin and eyes)
- Vision or hearing changes
- Gastrointestinal bleeding
- Enlarged spleen or liver
- Difficulty feeding
If you notice your child experiences any of the previous symptoms, including facial ones, immediately contact your healthcare professional.
Causes
This genetic disorder occurs due to mutations (changes) of the 12 PEX genes. In most cases, babies who develop ZS have a mutation in the PEX1 gene. Generally, these genes help cells function properly. However, peroxisomes are responsible for breaking down fats and toxins, as well as play an important role in the following parts and organs of the body. For example:
- Heart
- Kidneys
- Eyes
- Brain
- Bones
- Liver
- Nerves
Who Gets Zellweger Syndrome?
This condition often runs in families, and it is an autosomal recessive disorder. It means this genetic condition happens when the baby receives abnormal genes from both biological parents. However, there is a 50% chance that the children will not develop the condition and will become carriers if both biological parents have this abnormal gene. When the newborn becomes a carrier, it means he/she will not develop the disease, but can pass the gene to him/her children in the future.
Prevention
However, there is no way to prevent this syndrome because experts do not fully understand why it happens. Moreover, babies with Zellweger syndrome do not live more than 12 months of age. Some people with Refsum or Heimler may live into adulthood. If you have a family history of the disease or suspect you may have ZS, it is advised to perform some genetic tests before pregnancy to make sure you do not have the abnormal gene and evaluate the risks of having a child with ZS.
Diagnosis
Physicians often perform a physical examination to check for abnormalities linked to the disease (such as facial abnormalities). They may also perform some tests to confirm the condition and exclude others that cause similar symptoms. Check some examples below:
- Urine and Blood tests – These tests are often done to check for some substances (such as fat molecules) that are high in people with ZS.
- Imaging tests – Doctors usually perform an ultrasound or a brain MRI (magnetic resonance imaging) scan to determine how well certain organs work. These include the brain, kidneys, liver, and others.
- Genetic testing – During this test, doctors will take a sample of blood to check for abnormal genes (mutated PEX genes).
In addition, when doctors suspect your child may have Zellweger syndrome, they may perform some tests (such as blood tests or imaging tests) during pregnancy to check for the disease.
Treatment
It is not possible to cure this condition. That’s why treatment focuses on relieving the symptoms and preventing life-threatening complications. Treatments are also different because they depend on which part of the body is affected. For instance, physicians may recommend a feeding tube for babies with difficulty eating.
Frequently Asked Questions
What should I do if I have the Zellweger syndrome gene mutation?
When genetic tests confirm you are a carrier of the abnormal gene that causes ZS, you should discuss it with your healthcare professional, especially if you plan to have children. However, if you have a child with ZS, you should talk with a team of neonatologists to make the best treatment plan for your child.
What is the life expectancy for individuals with Zellweger syndrome?
Usually, people with ZS do not survive more than the first year of their life. If your child develops a mild or moderate form of the disease, he/she may live into adulthood.
What is the cause of death for Zellweger syndrome?
In most cases, babies with ZS die before the first year of life due to severe liver disease. However, death may also happen due to gastrointestinal bleeding, pneumonia (which often leads to septic shock), and other problems. Ask your healthcare provider if you have additional questions.
