What is metachromatic leukodystrophy (MLD)?
Enzymes are proteins that help break down, or metabolize, substances in the body. If certain enzymes aren’t present, the body will be unable to metabolize a substance. If the substance remains in the body, it may build up. This can cause significant health complications.
Metachromatic leukodystrophy (MLD) occurs when an enzyme known as arylsulfatase A (ARSA) isn’t present in the body. ARSA breaks down fats known as sulfatides. Without ARSA, sulfatides build up in cells, especially in the cells of the nervous system, causing damage to various organs, including the kidneys and nervous system, which includes the brain and spinal cord. These substances affect the nerves in the body, damaging them so that they’re unable to send electrical impulses. Muscle weakness or lack of muscle control is common in people with MLD and is a result of this type of damage to the nerves.
How common is metachromatic leukodystrophy (MLD)?
MLD is a rare disorder that’s reported to occur in one in 40,000 to 160,000 people worldwide. This number is higher in certain genetically isolated populations. Please discuss with your doctor for further information.
What are the symptoms of metachromatic leukodystrophy (MLD)?
The common symptoms of metachromatic leukodystrophy (MLD) are:
- Abnormal muscle movement
- Behavior problems
- Decreased mental function
- Decreased muscle tone
- Difficulty walking
- Difficulty eating or feeding
- Frequent falls
- A loss of muscle control
- Problems with nerve function
- Difficulty speaking
- Difficulty swallowing
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes metachromatic leukodystrophy (MLD)?
MLD is usually caused by the lack of an important enzyme called arylsulfatase A (ARSA). Because this enzyme is missing, chemicals called sulfatides build up in the body and damage the nervous system, kidneys, gallbladder, and other organs. In particular, the chemicals damage the protective sheaths that surround nerve cells.
The disease is passed down through families (inherited). You must get a copy of the defective gene from both your parents to have the disease. Parents can each have the defective gene, but not have MLD. A person with one defective gene is called a “carrier.”
Children who inherit only one defective gene from one parent will be a carrier, but usually will not develop MLD. When two carriers have a child, there is a 1 in 4 chance that the child will get both genes and have MLD.
What increases my risk for metachromatic leukodystrophy (MLD)?
Please discuss with your doctor for further information.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is metachromatic leukodystrophy (MLD) diagnosed?
The health care provider will perform a physical exam, focusing on the nervous system symptoms.
Tests that may be done include:
- Blood or skin culture to look for low arylsulfatase A activity
- Blood test to look for low arylsulfatase A enzyme levels
- DNA testing for the ARSA gene
- MRI of the brain
- Nerve biopsy
- Nerve signaling studies
How is metachromatic leukodystrophy (MLD) treated?
Metachromatic leukodystrophy can’t be cured, and there are few treatment options. But, your doctors will work with you to help manage your signs and symptoms and try to improve your quality of life. Ask Talk to your doctor about the possibility of participating in a clinical trial.
Metachromatic leukodystrophy can be managed with several treatments:
- Medications may reduce your signs and symptoms and relieve your pain.
- Stem cell transplant. Hematopoietic stem cell transplants sometimes have slowed the progression of metachromatic leukodystrophy by introducing healthy cells to help replace diseased ones.
- Physical, occupational and speech therapy. You may have physical therapy to promote muscle and joint flexibility and maintain your range of motion as much as possible. You may need a wheelchair, walker or other assistive devices as your condition progresses. You may have occupational and speech therapy to improve your quality of life.
- Nutritional assistance. You and your family may work with a nutrition specialist (dietitian) to make sure you’re getting the right nutrition. Eventually, it may become difficult to swallow food or liquid. You may need assistive feeding devices as your condition progresses.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage metachromatic leukodystrophy (MLD)?
The following lifestyles and home remedies might help you avoid metachromatic leukodystrophy (MLD):
Although there’s still no cure for MLD, more treatments are being developed. Talk to your doctor about participating in clinical studies.
MLD is a genetic disorder that cannot be prevented. However, if the condition runs in your family, you may want to consider genetic testing and counseling to see if you’re a carrier. Genetic counseling may help you to be better informed about the risks of passing the gene on to your children.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: November 22, 2017 | Last Modified: November 22, 2017
Metachromatic Leukodystrophy. https://www.healthline.com/health/metachromatic-leukodystrophy#overview1. Accessed November 22, 2017.
Metachromatic leukodystrophy. https://www.mayoclinic.org/diseases-conditions/metachromatic-leukodystrophy/symptoms-causes/syc-20354733. Accessed November 22, 2017.