Krabbe disease, also known as globoid cell leukodystrophy, is part of a family of disorders known as leukodystrophies. Krabbe disease results from a deficiency in an enzyme known as galactocerebrosidase (GALC), which is important for production of the protective covering around nerve cells called myelin.
Early signs of the condition include delayed mental and physical development, muscle weakness, and feeding difficulties. As the condition progresses, children start to lose their ability to move, chew, swallow, see and breathe. Most commonly, Krabbe disease appears before the age of one and sadly, infants affected by Krabbe disease have a shortened life expectancy of approximately two years.
Rarely, symptoms can be milder and don't appear until late childhood or even adulthood. Those who experience Krabbe disease later in life present with seizures, muscle weakness, nerve pain and reduced sensitivity, and vision loss. Treatment is focussed on managing individual symptoms.
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.
Krabbe disease 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 condition.
If both parents are carriers of Krabbe disease, there's a one in four chance that their children could develop symptoms.
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 condition in your child. Eugene offers an inclusive genetic carrier screening panel that includes Krabbe disease, 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
The biggest benefit of screening for Krabbe disease 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 condition is low.
Since 90% of children that have a recessive genetic condition like Krabbe disease 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 condition in the first place.