Canavan disease is a hereditary condition that prevents the brain’s nerve cells (neurons) from properly sending and receiving information.
Although this fatal neurological condition can affect children of any ethnic background, it’s most common in the Ashkenazi Jewish population. About one in every 6,400 to 13,500 people born of Ashkenazi descent are affected. Ashkenazi Jews have their roots in eastern Poland, Lithuania, and western Russia.
The rate of Canavan disease in the general population is likely much lower, though it isn’t known for sure.
Children born with Canavan disease may not have any noticeable symptoms at birth. Signs of the condition usually start to appear within a few months.
What are the symptoms?
The symptoms of the disease can vary greatly. Children affected by the condition may not share the same symptoms.
Some of the most common symptoms are:
- larger-than-normal head circumference
- poor head and neck control
- reduced visual responsiveness and tracking
- unusual muscle tone, leading to stiffness or floppiness
- unusual posture, with legs often kept straight and arms flexed
- difficulty eating, with food sometimes flowing up into the nose
- difficulty sleeping
An increase in head circumference typically develops abruptly. Other symptoms develop more slowly. For example, vision problems may become more obvious as a baby’s development slows down. It is a progressive condition, meaning its symptoms can worsen over time
Causes of Canavan disease
Canavan disease is one of several genetic disorders known as leukodystrophies. These conditions affect the myelin sheath, the thin coating around nerves. Myelin also helps transmit signals from one nerve to another.
Children affected by this condition lack an important enzyme called aspartoacylase (ASPA). This natural chemical helps break N-acetylaspartic acid down into the building materials that form myelin. Without ASPA, myelin can’t form properly, and nerve activity in the brain and the rest of the central nervous system is affected.
Both parents must carry the defective gene that causes an absence of ASPA in order for their child to develop Canavan disease. When both parents have the gene, each child will have a 25 percent chance of developing this genetic disorder. About one in 55 Ashkenazi Jews carry the Canavan disease genetic mutation.
Canavan disease Diagnosis
A prenatal blood test can reveal whether the fetus has Canavan disease.
If you carry the Canavan gene mutation, you may want to discuss genetic testing prior to becoming pregnant.
If you’re already pregnant, you may want to have the blood test done to see if your baby has been affected.
Treatment options are available for Canavan disease?
There isn’t a cure for Canavan disease. The goal of treatment is to reduce your child’s symptoms and improve their quality of life.
Your child’s treatment plan will vary depending on their individual symptoms. Your child’s pediatrician will work with you and your child to determine how to best meet their needs.
For example, feeding tubes can also be helpful for children who have serious swallowing problems. These tubes can ensure that your child is getting all of the nutrients they need and enough fluids to stay hydrated.
Physical therapy and adaptive equipment may be helpful in promoting better posture. Lithium or other medications may be helpful in controlling seizures.