An inherited disorder that usually affects the nervous system and muscles and causes lactic acid to build up in the body is called MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) syndrome. In most cases, the symptoms are noticeable before the age of 20, but not always. This syndrome is a mitochondrial disease.
Moreover, specific parts of the cells that help produce chemical energy are called mitochondria. Thus, the body uses carbohydrates to produce energy, and a by-product is lactic acid. While most people begin to experience symptoms before the age of 20, they can occur before the age of 2 or after 40. Generally, it affects about 1 in 4,000 people.
Symptoms
This syndrome can negatively affect any part of the body because mitochondria are present in all cells of the body. Most people who develop this genetic condition have diabetes and deafness (hearing loss) before the onset of brain-related (neurologic) symptoms. Check below some symptoms often noticed in people with MELAS syndrome:
- Behavioral changes
- Numbness or tingling that affects only one part of the body
- Frequent headaches with vision or speech changes
- Seizures
- Dizziness
- Loss of balance
- Confusion
- Paralysis (inability to move)
- Slurred speech
- Vision problems (such as double vision, blurred vision, or vision loss)
- Weakness that also affects only one side of the body
This syndrome may also cause symptoms that affect other parts of the body. These include:
- Extreme tiredness (fatigue)
- Muscle cramps
- Abdominal pain
- Frequent episodes of vomiting
- Short stature
If you or your child experiences any of the previous symptoms, immediately contact your healthcare professional. Otherwise, it may lead to serious and even life-threatening complications.
Causes and Risk Factors
This condition occurs due to certain genetic variations. These are differences in the sequence of the DNA that normally gives information to cells when to grow, multiply, and die. However, in people with MELAS syndrome, DNA gives different instructions to cells, which affect their ability to work properly. Usually, people who develop this condition get the abnormal gene from one of their biological parents during conception. The condition may occur even if only one parent has the abnormal gene.
Healthcare professionals have also identified some factors that may increase your risk of developing this syndrome. Examples include:
- Family history of the disease – If you have a parent or sibling with this condition, your risk of developing it significantly increases.
- Genetic mutations – While the most common cause is a mutation in the m.3243A part of the MT-TL1 gene, there are other variants.
- Heteroplasmy level – The severity and risk of the MELAS syndrome are linked to the amount of mutated mitochondria (especially in the muscles and nervous system).
- Infections – Certain infections may trigger severe symptoms in people with compromised mitochondria.
- Metabolic problems – Commonly, severe hyperlactatemia (high lactic acid) is associated with increased death rate.
Complications and Prevention
People with this syndrome may also experience some complications, especially if they leave it untreated. Check some of them below:
- Hearing or vision loss
- Diabetes
- Intellectual disability with an increased risk for dementia
- Muscle problems (including inability to control muscles, muscle spasms, and others)
- Liver disease
- Gait and balance issues
- Epilepsy
- Frequent migraine-like headaches
- Cardiovascular problems (including cardiomyopathy, heart failure, and arrhythmia)
- Psychiatric disorders – These include major depressive disorder, bipolar disorder, autism spectrum disorder, schizophrenia, and others
- Gastrointestinal problems (such as severe vomiting or belly pain)
- Renal failure
This article does not contain all possible complications of MELAS syndrome. However, you can talk with your doctor about measures to reduce the risk or even prevent them.
In addition, there is no way to reduce the risk or prevent this condition because it happens due to an abnormal gene that is passed from the biological parents during conception. However, you can perform some genetic tests before getting pregnant to make sure you do not have the mutated genes that cause MELAS syndrome. Generally, it is very important to understand the risks of having children with this genetic disorder.
Diagnosis
Sometimes, diagnosing this syndrome is quite difficult because it can cause symptoms similar to those of other health conditions. However, the diagnosis often begins with a physical examination and questions about your symptoms and family history. They may also perform some tests to confirm or rule out MELAS syndrome. Check some examples below:
- Genetic tests
- Tests of cerebrospinal fluid, urine, and blood
- Imaging tests – The following tests are usually used by doctors to get detailed images of different structures and organs in the body. They often perform X-rays, ultrasound, CT (computerized tomography) scans, and MRI (magnetic resonance imaging) scans.
- Muscle biopsy – During this procedure, doctors will take a sample of the affected muscle for testing.
Treatment
Unfortunately, it is not possible to cure this syndrome. That’s why the treatment goal is to reduce the symptoms, prevent serious complications, and improve your quality of life. Check below some options often recommended by doctors for people with MELAS syndrome:
- Antiseizure medicines (you should avoid Valproate)
- Coenzyme Q10 or L-carnitine – These are special products that help increase mitochondrial energy output and slow the progression of the disease.
- L-arginine and L-citrulline – Doctors often recommend these products to reduce the amount of stroke-like effects.
- Insulin or Metformin – Physicians may recommend these medications for people who develop diabetes.
- Vaccines – Those who develop MELAS syndrome are at increased risk of developing infections. Hence, you should keep up with annual vaccinations, including vaccines for COVID-19, flu, pneumonia, and other serious infections.
If you develop hearing loss, doctors may recommend cochlear implants to improve hearing.
Frequently Asked Questions
What can I expect if I have MELAS syndrome?
This condition cannot be cured, and once you develop it, you will need treatment for the rest of your life. Moreover, your family, friends, and support groups may help you cope with negative thoughts and mental disorders that can occur.
What is the life expectancy with MELAS syndrome?
Unfortunately, it is difficult to estimate the lifespan of a person with MELAS syndrome because it affects multiple parts of the body. In general, it depends on the severity of the condition, overall health, your response to treatment, and other factors. For more details, discuss it with your doctor.
What are the first signs of MELAS syndrome?
These include:
- Hallucinations
- Seizures
- Hemiparesis (temporary muscle weakness or paralysis)
- Behavioral changes
- Speaking problems
Do not hesitate to see a doctor if any of the symptoms listed above happen. If you have any other questions, ask your healthcare provider.
