Worried about your child's brain development? Let's talk about Metachromatic Leukodystrophy (MLD)

As you may have noticed, some young children develop differently than others. It's normal for a parent to feel a great deal of stress when they start walking or talking, and they notice slight delays. Today we're going to talk about a genetic disease that can be just as stressful, but is very rare. It's called metachromatic leukodystrophy, or MLD for short. Although the name may sound complicated, let's try to keep it simple.

What is this metachromatic leukodystrophy (MLD)?

Simply put, `(MLD)` is a very rare genetic disease. It mainly affects our central nervous system, that is, the white matter of the brain and spinal cord , as well as the peripheral nerves in our limbs. `(MLD)` is another disease that belongs to the group of `(Lysosomal storage diseases)`.

Now you may be wondering how this white matter gets damaged. There is a fatty substance called `(Sulfatides)` inside our cells. This should normally break down. But in a person with `(MLD)`, these `(Sulfatides)` accumulate inside the cells. When this accumulates, the `(myelin sheath)`, which is the protective covering around the nerve fibers, does not develop properly. This myelin sheath is like the plastic sheath around a wire. This myelin is what gives the white matter its white color.

So, what happens when this myelin sheath is damaged? Our mental function and motor function, that is, muscle movement, gradually decrease. The symptoms of ``(MLD)`` become more severe over time, and in many cases, death can occur within a few years of diagnosis.

This is called metachromatic leukodystrophy for a special reason. When a pathologist looks at it under a microscope, the cells with these sulfatides absorb color differently than the other cells around them. That's why it's called "metachromatic." "Leukodystrophy" means the gradual destruction of white matter ("leuco" means white, and "dystrophy" means decay).

What are the main types of `(MLD)`?

There are three main forms of this disease (MLD). These are divided according to the age at which they develop.

Late infantile MLD

This is the most common type of MLD. It usually affects babies between 12 and 20 months of age, or about a year and a half. Symptoms include difficulty walking, developmental delays, blindness, and dementia. Sadly, most children with this condition die before the age of 5. About 50% to 60% of MLD patients fall into this category.

Juvenile MLD (MLD)

This type is usuallyIt affects children between the ages of 3 and 10. These children may show symptoms such as intellectual disability, behavioral problems, seizures, and dementia. A child with this type of MLD may die within 10 to 20 years of diagnosis. About 20% to 30% of MLD patients fall into this category.

Adult MLD

It usually begins after the age of 16, that is, in adolescence or later. Symptoms include mental changes, seizures, and dementia. Death can occur between 6 and 14 years after diagnosis. About 15% to 20% of MLD patients fall into this category.

How rare is the disease `(MLD)`?

Yes, MLD is a rare disease. According to researchers, it affects about one in 40,000 people in the United States. However, it is more common in some isolated populations. For example, the Navajo people have been found to have a rate of about one in 2,500 people.

What are the symptoms of `(MLD)` disease?

The symptoms of MLD can vary depending on the type. But in general, all types gradually deteriorate the functioning of the nervous system. This means that things like muscle movement, intelligence, mood, and personality are affected.

Symptoms of late infantile MLD

Babies with this type of `(MLD)` may initially appear to develop normally, but after about a year, they begin to show these symptoms:

• It becomes difficult to walk , eventually becoming impossible to walk at all.
• Muscle weakness (hypotonia) occurs.
• Developmental delays are seen.
• Difficulty speaking (dysarthria).
• Gradually , vision is lost and blindness occurs.
• Difficulty swallowing (dysphagia).
• Dementia occurs.

Symptoms of juvenile MLD

Children with this type of MLD may show symptoms such as:

• Intellectual abilities decline. This may be noticeable in schoolwork.
• Behavior problems arise.
• Changes in personality are seen.
• Unable to control muscle movements.
• Peripheral neuropathy occurs.
• Seizures are coming.
• Dementia occurs.

Symptoms of adult MLD

Mental changes are the main symptoms seen in adults with MLD.Physical movement problems may be absent or minimal. The first symptoms may be alcohol use disorder, substance use disorder, or problems at school/work.

Other features are:

• Mental problems, such as hallucinations, psychosis, or schizophrenia .
• Seizures.
• Peripheral neuropathy.
• Dementia.

Sometimes doctors may misdiagnose MLD in adults as bipolar disorder or dementia.

What causes `(MLD)`?

The main cause of MLD is a gene mutation inherited from both parents.

Many MLD patients have a mutation in the ARSA gene. This gene instructs the production of an enzyme called Arylsulfatase A. This enzyme helps break down the aforementioned sulfatides. So, due to the gene mutation, people with MLD do not produce this enzyme, or produce it very little. As a result, sulfatides accumulate. This accumulation of sulfatides is toxic to the white matter of the nervous system, damaging those cells.

Some MLD patients may also have mutations in the PSAP gene, which also provides instructions for breaking down sulfatides.

Is this something that comes from genes?

Yes, `(MLD)` is a genetic disease. It is inherited in an `(autosomal recessive)` pattern. This means that both parents of a person with this disease carry one copy of this mutated gene (`(carriers)`). However, those parents usually do not show symptoms. For a child to develop the disease, this defective gene must be inherited from both the mother and the father.

What are the possible side effects of `(MLD)`?

The main side effects that can occur due to `(MLD)` are:

• Neurocognitive decline (dementia)
• Blindness due to optic nerve atrophy.
• Malnutrition.
• Aspiration pneumonia is caused by food or liquids entering the airway .
• Death.

How is MLD diagnosed?

If a doctor (usually a neurologist) suspects MLD based on your or your child's symptoms, they may order tests such as:

• Genetic testing: This can detect mutations in the genes ``ARSA'' and ``PSAP'' that cause ``MLD''.
• Biochemical testing:This can measure the level of `(Sulfatides)` in your body. For example, `(Sulfatase)` enzyme activity and `(Sulfatides)` levels in urine are tested.
• Brain MRI: This helps confirm the diagnosis of MLD. Since people with MLD have a specific pattern of myelin loss, an MRI can be used to determine whether myelin is present or not.

Once you have been diagnosed with MLD, you may be asked to do further tests to see how much the disease has affected your nervous system. These include:

• Neurocognitive testing.
• Neuropsychological testing.
• Nerve conduction tests.

What are the treatments for `(MLD)`?

Unfortunately, there is no cure for MLD. The main goal of treatment is to control symptoms and improve quality of life. Doctors may recommend stem cell transplants to slow the progression of the disease, either before symptoms appear or in children with mild symptoms.

Various types of medications can be given to control symptoms, such as:

• Anticonvulsant medications for seizures.
• Reduce muscle stiffness (spasticity) (muscle relaxants).
• Antidepressants for mental problems.
• NSAIDs and other painkillers for pain.

Other treatments that can be used include:

• Physical therapy to reduce muscle strength and stiffness.
• Occupational therapy to help with daily tasks.
• Speech therapy for speaking and swallowing difficulties.
• Psychotherapy for mental health problems.
• Percutaneous endoscopic gastronomy (PEG) is a method of feeding through a tube into the stomach for eating disorders and nutritional problems.

You or your child may also be eligible for palliative care . Palliative care is the care that provides relief from symptoms, comfort, and support for people with serious illnesses such as MLD. It also provides significant relief to those caring for the patient. It can be done in conjunction with other treatments for MLD.

What happens to someone who has the disease `(MLD)`? (Progress of the disease)

The prognosis for MLD is not very good. It is a progressive disease. This means that the symptoms spread and get worse. A person with MLD loses muscle and mental function completely, and eventually dies.

How long can you live with `(MLD)`?

How long someone with MLD lives depends on the age at which the disease is first diagnosed.

• Late infantile form:Death usually occurs within five to six years of diagnosis.
• Juvenile form: This form of the disease is less common and usually results in death within 10 to 20 years of diagnosis.
• Adult form: Death usually occurs between 6 and 14 years after diagnosis.

Is there a way to prevent `(MLD)`?

Because MLD is a genetic disease, there is nothing that can be done to prevent it.

However, if someone in your family has MLD and you are planning to have a child, it is a good idea to seek genetic counseling to find out if you are also a carrier of this genetic mutation.

How do you care for someone with `(MLD)`? / What do you do if you or your child has `(MLD)`?

If you or your child has MLD, it is important to get the best medical care possible. You need to advocate for it and be passionate about it. Only then can you maintain the best possible quality of life.

Also, it's very valuable to join a support group to meet others who have similar experiences to yours and share ideas.

When should you see a doctor?

If you or your child has MLD, you should meet with your medical team regularly to see how the disease is progressing and adjust your treatment plan as needed.

A diagnosis of (MLD) can be overwhelming. However, your healthcare team can help you develop a symptom management plan that works for you. It's important to make sure you're getting the support you need and to stay on top of your health. Remember, your healthcare team is always there to help you and your family.

If we put together the things we talked about (Take-Home Message)

Okay, so we talked a lot about `(Metachromatic Leukodystrophy - MLD)` today, didn't we?

Simply put, `(MLD)` is a very rare, genetic disease. It damages the white matter of the brain and nervous system. It is caused by the accumulation of a type of fat called `(Sulfatides)` inside the cells.

There are three forms of this disease – infantile, adult, and pediatric. Each has different symptoms and progression.

Unfortunately, there is no cure for this disease. However, there are various treatments that can help control symptoms and maintain a good quality of life. Stem cell transplants can sometimes help control the spread of the disease.

Although this is a genetic disease and cannot be prevented, genetic counseling is important if there is a family history.

The most important thing is to provide the best care and support for the person with the disease.Proper medical treatment, palliative care, and the love and attention of family are all invaluable. You are not alone, and there are doctors, counselors, and support groups to help you on this journey.

` Metachromatic leukodystrophy, MLD, genetic diseases, neurological diseases, white matter, myelin, pediatric diseases