What is Leukodystrophy?
Leukodystrophy is not
just a disease; it is actually a group of diseases that affect the central
nervous system. Doctors are constantly discovering new forms of leukodystrophy,
but there are currently 52 different types known to specialists.
Most leukodystrophies
are genetic, meaning they are passed from parent to child. Sometimes symptoms
appear in early childhood. But because the diseases are progressive, meaning
they get worse over time, some babies born with a form of leukodystrophy may
appear healthy.
Symptoms
The only thing that
all leukodystrophies have in common is that they cause the abnormal development
or destruction of the myelin sheath in the brain. It is a white fat that
protects the nerves in the brain. Without it, your nervous system cannot
function properly.
But each
leukodystrophy affects myelin differently. This means that children can have
many problems, including:
- Balance and mobility problems
- Behavioral and learning disabilities
- Bladder issues
- Breathing difficulties
- Developmental delays
- Hearing, speech, and vision problems
- Muscle control disorders
- Seizures
For example, one type
of leukodystrophy, Canavan disease, causes decreased muscle tone, especially in
the neck, as well as abnormally straight legs and bent arms. It may also
include symptoms such as blindness and seizures.
Sometimes symptoms
appear shortly after the baby is born, and sometimes even into adulthood. For
example, signs of Refsum disease usually appear around age 20, but may occur
before the age of 50. Some of the common symptoms include retinal degeneration,
deafness, and loss of smell.
Although each
leukodystrophy is different, the most common problem is that the child's health
gradually deteriorates in one way or another, even if it seemed good at first.
This may be a deterioration in their vision, hearing, speech, ability to eat,
behavior or thoughts. Because symptoms can vary greatly, leukodystrophy can be
difficult to diagnose.
Causes
Most leukodystrophies
are hereditary, meaning they are passed down through family genes. Some of them
may not be hereditary, but are always caused by a genetic mutation. One child
in your family may have leukodystrophy and some may not.
For example,
Alexander's disease is not inherited, so your child may have the defective gene
even if neither you nor your partner has it.
If you have a child
with leukodystrophy and plan to have more children, you may want to consider
genetic counseling. This can help you understand your chances of having another
child with leukodystrophy.
Diagnosis
Diagnosis of
leukodystrophy can be difficult. Often doctors need to use more than one type
of test, including:
- Blood and urine analysis
- Computerized tomography scans
- Genetic testing
- Magnetic resonance imaging scans
- Psychological and cognitive tests
Treatment
There is no cure for
most types of leukodystrophy. Treatment depends on the type, and doctors treat
the symptoms of the disease with medications and special types of physical
therapy, occupational therapy, and speech therapy. Some people may need extra
help with learning or nutrition.
In some cases, a bone marrow transplant can help by slowing or stopping the progression of the disease. Scientists are also studying whether gene therapy or the replacement of certain enzymes can help treat certain types of leukodystrophy.