Canavan disease causes interrupted communication of the nerves that connect the brain to the muscles. This leads to abnormal muscle tone (weakness or stiffness), and a large, poorly controlled head. Canavan disease is usually diagnosed within the first 3 to 6 months of life, when babies do not meet their early motor milestones. Signs include lack of head control and the inability to roll over or sit without support. Sadly, progressive brain degeneration (leukodystrophy) is rapid and affects a baby's ability to eat and move independently. Paralysis, blindness, and hearing loss may also occur.
There is no cure, and treatment is focused on managing the symptoms and providing supportive care. Life expectancy is usually into the teens.
There is a milder, less common form of Canavan disease where children have mildly delayed development of speech and motor skills.
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.
Canavan 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 disease.
If both parents are carriers of Canavan 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 disease in your child. Eugene offers an inclusive genetic carrier screening panel that includes Canavan 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 Canavan 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 disease is low.
Since 90% of children that have a recessive genetic disease like Canavan 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 disease in the first place.