Answers to questions families often have about caring for their child with leukodystrophies

The leukodystrophies are a group of inherited conditions that cause abnormalities of myelin, which makes up the sheaths of many nerves in the white matter of the brain and that connect with muscles and sensory organs in the body. Myelin greatly speeds the transmission of nerve impulses and those nerves cannot function properly if it is abnormal or absent.

Leukodystrophies comprise more than 50 conditions; a full list of known leukodystrophies can be found at Known Leukodystrophies (ULF).

Most leukodystrophies are inherited (passed from parent to child) and are caused by one or two abnormal copies of certain genes. A specific genetic or metabolic defect can be identified for about 50% of children with a leukodystrophy. Other leukodystrophies arise from a sporadic genetic mutation—one that occurred as an “accident” in the creation of an egg or sperm.

Symptoms are different for each type of leukodystrophy and can vary based on severity and the child’s age. Children with leukodystrophy may have:

• Increased muscle tone (tightness, hypertonia) in arms and legs, causing spasticity
• Decreased muscle tone (hypotonia) in the body overall
• Problems with balance
• Difficulties with walking, talking, and fine motor control
• Delay and decline in brain (cognitive) function
• In the most severe cases, a decline in motor function that causes problems with breathing, chewing, and digestion

People with leukodystrophy may show a decline in meeting developmental milestones during infancy or toddlerhood or a decline in cognitive and motor abilities during childhood. For some, the condition presents itself when they are adults. Some leukodystrophies progress rapidly, while others progress slowly if at all.

Some children with leukodystrophies are thought to have cerebral palsy, the result of brain injury in prenatal development or within the first year of life, but are later found to have a leukodystrophy. This diagnosis should be considered in any child who stops meeting developmental milestones—the most common presentation—or has developmental regression.

The initial diagnosis is made by a brain MRI and sometimes a CT scan that demonstrate white matter abnormalities. Further testing is usually needed to determine the specific form of leukodystrophy. Specific testing for leukodystrophies with a known genetic component is usually done by blood testing. A spinal tap may be used to obtain spinal fluid for measurement of white blood cell count or interferon.

While research is ongoing, there is no known cure for leukodystrophy. Outcomes vary by condition but, with some leukodystrophies, there may be a progressive decline in neurologic function. This can make it difficult for affected people to do activities of daily living, such as walking, bathing, and dressing.

In general, leukodystrophies are severe diseases. In one study, 51% of children in a large cohort walked, and 28% of children achieved the ability to track visually. [Bonkowsky: 2010] In a few leukodystrophies, the disease course can be slowed by stem cell transplantation early on. [Pagon: 2014]

However, not enough is known about leukodystrophy and even the top researchers are still learning. Children can be very resilient and may prove dire predictions to be false.

If family members older than your child with leukodystrophy aren't showing signs or symptoms of the disease, it is unlikely that they have leukodystrophy. Because leukodystrophy can be genetically inherited, children who don’t show symptoms may be carriers. They may want to be tested to guide later decisions about having children of their own. If you have a baby younger than the child with this condition, you should ask your neurologist about his or her risk.

Current treatment for most leukodystrophies is supportive. This may include physical, occupational, and speech therapy; treatments for abnormal muscle tone; and feeding tubes and g-tubes to help with nutrition. For a few types of leukodystrophy, bone marrow transplantation, stem cell treatment, and experimental drug treatments may be available. These have not been found to cure the condition, but may slow certain leukodystrophies.

As with any child, life will be busy. Children with leukodystrophy will likely need more supports, such as extra appointments with doctors and therapists, and may be more dependent on family members and caregivers to help them with their needs. Most children with leukodystrophy will have significant problems with walking, talking, and activities of daily living.

The leukodystrophies have wide range of effects on health and well-being and vary in how the condition progresses. Some leukodystrophies cause a progressive downhill course in an affected child’s abilities and a shortened life span, while children with other types may retain a high level of functioning. Some children diagnosed with leukodystrophy are now adults. We encourage you to discuss your child's prognosis with your neurologist and primary care doctor.

Because children with leukodystrophy may have significant medical problems, changes for the family can be significant. A support group (see below) may be very helpful for you and your family. It is vital to get the right support and information. While it is important to stay up to date with the latest information about your child’s diagnosis, also focus on loving your child and enjoying time with them.

Since the type of leukodystrophy isn't known, it is impossible to predict the chances of your next child having the same condition. Probabilities range from a 1 in 2 chance if the leukodystrophy is inherited as a dominant trait to almost no chance if the leukodystrophy was sporadic.

You should consult a genetic counselor or ask your child's primary care doctor or neurologist about how likely it is for you to have another child with leukodystrophy.