Zellweger spectrum disorder (PEX1-related)

Zellweger spectrum disorder (ZSD) is a group of conditions with overlapping signs and symptoms, caused by variations in many different genes. There are 3 distinct forms of the condition that are defined by when symptoms first appear and how serious they are. How badly someone is affected is also influenced by the body's ability to breakdown fatty acid deposits.

Babies who are affected by Zellweger syndrome have weak muscles, feeding problems, hearing and vision loss, and seizures.

All forms of ZSD have a big impact on the quality of someone's life and their life expectancy. There are also no known treatments or cures and early intervention is really important in treating children with the condition.

Quick facts about Zellweger spectrum disorder (PEX1-related)
Genes: PEX1
Inheritance: Autosomal Recessive
Alternative Names: ZSD
Relevant resources for Zellweger spectrum disorder (PEX1-related)

A quick genetics rundown

As humans we have about 23,000 genes. These genes are like tiny instruction manuals that influence our health, growth and development. We inherit half of our genes from our biological mum and the other half from our biological dad. These genes are lined up on structures called chromosomes. Most of us have 23 pairs of chromosomes. The first 22 pairs are called autosomes and for the most part - these are the same among men and women. The 23rd pair determine our sex - two X chromosomes for a female and one X and one Y chromosome for males.

Learn more about genetics

How is Zellweger spectrum disorder (PEX1-related) inherited?

Zellweger spectrum disorder (PEX1-related) is known as an autosomal recessive condition. For autosomal recessive conditions, if a person has a variation in one copy of their gene, they are a carrier. This means that they are healthy because they also have a working copy of the gene. But, they can still pass their non-working copy to their child.

If the other parent also happens to be a carrier of the same gene, there is a 25% (1 in 4) chance that they both pass this gene variation on to their child — and as such, have a child affected by the disease.

If both parents are carriers of Zellweger spectrum disorder (PEX1-related), there’s a one in four chance that their children could develop symptoms.
Learn more about carrier screening

What is carrier screening?

Carrier testing is like a checkup for your genes. It tests to see if you carry a gene variation that could cause a serious genetic disease in your child. Eugene offers an inclusive genetic carrier screening panel that includes Zellweger spectrum disorder (PEX1-related), but there's a total 301 conditions that can be tested.

Eugene’s carrier test is a clinical grade test that can be done from the comfort of your own home — it’s just a saliva test. You're also paired with a genetic counsellor who provides mindful support and guidance every step of the way.

Learn more about carrier screening

Should parents screen for Zellweger spectrum disorder (PEX1-related) before or early in pregnancy?

The biggest benefit of screening for Zellweger spectrum disorder (PEX1-related) is that it can help future parents understand their reproductive risk so they can be ready and empowered to make more informed decisions. If neither partner are carriers, it provides reassurance and peace of mind that the risk of having a child with a genetic disease is low.

Since 90% of children that have a recessive genetic disease like Zellweger spectrum disorder (PEX1-related) had no previous family history of it, it often feels completely out of the blue for the parents. Getting screened is a way to know this risk in advance, which can help familes manage or even prevent the disease in the first place.

Wondering if this test is right for you?

Take a two minute quiz to find out.