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.

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

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

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

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

Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating of your heart and the widening or narrowing of your blood vessels. When something goes wrong in this system, it can cause serious problems, including:

• Blood pressure problems
• Heart problems
• Trouble with breathing and swallowing
• Erectile dysfunction in men

Autonomic nervous system disorders can occur alone or as the result of another disease, such as Parkinson's disease, alcoholism and diabetes. Problems can affect either part of the system, as in complex regional pain syndromes, or all of the system. Some types are temporary, but many worsen over time. When they affect your breathing or heart function, these disorders can be life-threatening.

Some autonomic nervous system disorders get better when an underlying disease is treated. Often, however, there is no cure. In that case, the goal of treatment is to improve symptoms.

NIH: National Institute of Neurological Disorders and Stroke

A genetic brain disorder is caused by a variation or a mutation in a gene. A variation is a different form of a gene. A mutation is a change in a gene. Genetic brain disorders affect the development and function of the brain.

Some genetic brain disorders are due to random gene mutations or mutations caused by environmental exposure, such as cigarette smoke. Other disorders are inherited, which means that a mutated gene or group of genes is passed down through a family. They can also be due to a combination of both genetic changes and other outside factors.

Some examples of genetic brain disorders include:

• Leukodystrophies
• Phenylketonuria
• Tay-Sachs disease
• Wilson disease

Many people with genetic brain disorders fail to produce enough of certain proteins that influence brain development and function. These brain disorders can cause serious problems that affect the nervous system. Some have treatments to control symptoms. Some are life-threatening.

Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.

Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder.

You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.

There are three types of genetic disorders:

• Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
• Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. Down syndrome is a chromosomal disorder.
• Complex disorders, where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example.

Genetic tests on blood and other tissue can identify genetic disorders.

NIH: National Library of Medicine