2022 ICD-10-CM Code E75.25

Information for Patients

What are leukodystrophies?

Leukodystrophies are a group of rare genetic disorders that affect the central nervous system (CNS). The CNS is made up of your brain and spinal cord. Leukodystrophies damage the white matter of your CNS. The white matter includes

• Nerve fibers, also called axons, which connect your nerve cells
• Myelin, a layer of proteins and fatty materials that covers and protects the nerve fibers. It also helps speed up signals between the nerve cells.

When the white matter is damaged, it can slow down or block the signals between nerve cells. This can cause many different symptoms, including trouble with movement, vision, hearing, and thinking.

There are over 50 types of leukodystrophies. Some types are present at birth, while others may not cause symptoms until a child becomes a toddler. A few types mainly affect adults. Most types get worse over time.

What causes leukodystrophies?

Leukodystrophies are caused by genetic changes. These changes are usually inherited, meaning that they are passed from parent to child.

What are the symptoms of leukodystrophies?

The symptoms of leukodystrophies depend on the type; they can include a gradual loss of

• Muscle tone
• balance and mobility
• Walking
• Speech
• Ability to eat
• Vision
• Hearing
• Behavior

There can also be other symptoms, such as

• Learning disabilities
• bladder issues
• Breathing problems
• Developmental disabilities
• Muscle control disorders
• Seizures

How are leukodystrophies diagnosed?

Leukodystrophies can be hard to diagnose because there are so many different types which can have different symptoms. Your health care provider may use many tools to make a diagnosis:

• Physical and neurological exams
• A medical history, including asking about family history
• Imaging tests, such as an MRI or CT scan
• Genetic testing to look for genetic changes that could cause leukodystrophies
• Lab tests

What are the treatments for leukodystrophies?

There is no cure for leukodystrophies. Treatment focuses on relieving symptoms and providing support. It may include

• Medicines to manage muscle tone, seizures, and spasticity (muscle stiffness)
• Physical, occupational, and speech therapies to improve mobility, function, and cognitive problems
• Nutritional therapy for eating and swallowing problems
• Educational and recreational programs

Stem cell or bone marrow transplantation can be helpful for a few types of leukodystrophy.

One type of leukodystrophy, CTX, is treatable if it is diagnosed early. It is treated with chenodeoxycholic acid (CDCA) replacement therapy.

NIH: National Institute of Neurological Disorders and Stroke

Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter. Sulfatide accumulation in myelin-producing cells causes progressive destruction of white matter (leukodystrophy) throughout the nervous system, including in the brain and spinal cord (the central nervous system) and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system).

In people with metachromatic leukodystrophy, white matter damage causes progressive deterioration of intellectual functions and motor skills, such as the ability to walk. Affected individuals also develop loss of sensation in the extremities (peripheral neuropathy), incontinence, seizures, paralysis, an inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. While neurological problems are the primary feature of metachromatic leukodystrophy, effects of sulfatide accumulation on other organs and tissues have been reported, most often involving the gallbladder.

The most common form of metachromatic leukodystrophy, affecting about 50 to 60 percent of all individuals with this disorder, is called the late infantile form. This form of the disorder usually appears in the second year of life. Affected children lose any speech they have developed, become weak, and develop problems with walking (gait disturbance). As the disorder worsens, muscle tone generally first decreases, and then increases to the point of rigidity. Individuals with the late infantile form of metachromatic leukodystrophy typically do not survive past childhood.

In 20 to 30 percent of individuals with metachromatic leukodystrophy, onset occurs between the age of 4 and adolescence. In this juvenile form, the first signs of the disorder may be behavioral problems and increasing difficulty with schoolwork. Progression of the disorder is slower than in the late infantile form, and affected individuals may survive for about 20 years after diagnosis.

The adult form of metachromatic leukodystrophy affects approximately 15 to 20 percent of individuals with the disorder. In this form, the first symptoms appear during the teenage years or later. Often behavioral problems such as alcoholism, drug abuse, or difficulties at school or work are the first symptoms to appear. The affected individual may experience psychiatric symptoms such as delusions or hallucinations. People with the adult form of metachromatic leukodystrophy may survive for 20 to 30 years after diagnosis. During this time there may be some periods of relative stability and other periods of more rapid decline.

Metachromatic leukodystrophy gets its name from the way cells with an accumulation of sulfatides appear when viewed under a microscope. The sulfatides form granules that are described as metachromatic, which means they pick up color differently than surrounding cellular material when stained for examination.