Learn About MELAS Syndrome

What is the definition of MELAS Syndrome?

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). The signs and symptoms of this disorder most often appear in childhood following a period of normal development, although they can begin at any age. Early symptoms may include muscle weakness and pain, recurrent headaches, loss of appetite, vomiting, and seizures. Most affected individuals experience stroke-like episodes beginning before age 40. These episodes often involve temporary muscle weakness on one side of the body (hemiparesis), altered consciousness, vision abnormalities, seizures, and severe headaches resembling migraines. Repeated stroke-like episodes can progressively damage the brain, leading to vision loss, problems with movement, and a loss of intellectual function (dementia).

Most people with MELAS have a buildup of lactic acid in their bodies, a condition called lactic acidosis. Increased acidity in the blood can lead to vomiting, abdominal pain, extreme tiredness (fatigue), muscle weakness, and difficulty breathing. Less commonly, people with MELAS may experience involuntary muscle spasms (myoclonus), impaired muscle coordination (ataxia), hearing loss, heart and kidney problems, diabetes, and hormonal imbalances.

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What are the causes of MELAS Syndrome?

MELAS can result from mutations in one of several genes, including MT-ND1, MT-ND5, MT-TH, MT-TL1, and MT-TV. These genes are found in the DNA of cellular structures called mitochondria, which convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA, known as mitochondrial DNA or mtDNA.

Some of the genes related to MELAS provide instructions for making proteins involved in normal mitochondrial function. These proteins are part of a large enzyme complex in mitochondria that helps convert oxygen, fats, and simple sugars to energy. Other genes associated with this disorder provide instructions for making molecules called transfer RNAs (tRNAs), which are chemical cousins of DNA.  These molecules help assemble protein building blocks called amino acids into full-length, functioning proteins within mitochondria.

Mutations in a particular transfer RNA gene, MT-TL1, cause more than 80 percent of all cases of MELAS. These mutations impair the ability of mitochondria to make proteins, use oxygen, and produce energy. Researchers have not determined how changes in mtDNA lead to the specific signs and symptoms of MELAS.  They continue to investigate the effects of mitochondrial gene mutations in different tissues, particularly in the brain.

How prevalent is MELAS Syndrome?

The exact incidence of MELAS is unknown. It is one of the more common conditions in a group known as mitochondrial diseases. Together, mitochondrial diseases occur in about 1 in 4,000 people.

Is MELAS Syndrome an inherited disorder?

This condition is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children.

In most cases, people with MELAS inherit an altered mitochondrial gene from their mother. Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MELAS.

Who are the top MELAS Syndrome Local Doctors?
Highly rated in

Columbia University Department Of Neurological Surgery

New York, NY 

M Hirano is a Neurologist in New York, New York. Dr. Hirano has been practicing medicine for over 36 years and is rated as an Elite doctor by MediFind in the treatment of MELAS Syndrome. He is also highly rated in 35 other conditions, according to our data. His top areas of expertise are MELAS Syndrome, Mitochondrial Neurogastrointestinal Encephalopathy Disease, Progressive External Ophthalmoplegia, and Intestinal Pseudo-Obstruction. He is board certified in Neurology and licensed to treat patients in New York.

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Tawam Hospital

Sharjah, SH, AE 

Ayman Hattab-El is in Sharjah, United Arab Emirates. Hattab-El is rated as an Elite expert by MediFind in the treatment of MELAS Syndrome. He is also highly rated in 16 other conditions, according to our data. His top areas of expertise are MELAS Syndrome, Neu Laxova Syndrome, Lactic Acidosis, and Bilateral Renal Agenesis Dominant Type.

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Highly rated in

Kurume University Hospital

Kurume, JP 

Yasutoshi Koga is in Kurume, Japan. Koga is rated as an Elite expert by MediFind in the treatment of MELAS Syndrome. They are also highly rated in 3 other conditions, according to our data. Their top areas of expertise are MELAS Syndrome, Pyruvate Decarboxylase Deficiency, Precocious Puberty, and Pyruvate Dehydrogenase Deficiency.

What are the latest MELAS Syndrome Clinical Trials?
The International Database for Leigh Syndrome
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A Phase IIb Open-label, Multi-centre, Extension Study to Explore the Long-term Safety and Efficacy of KH176 in Subjects With a Genetically Confirmed Mitochondrial DNA tRNALeu(UUR) m.3243A>G Mutation Who Have Completed the KHENERGYZE Study KH176-202.
What are the Latest Advances for MELAS Syndrome?
MELAS syndrome: an acute stroke-like episode complicated by renal tubular acidosis.
Concomitant Mitochondrial Diabetes and Myopathy Mistook for Complications of Immunosuppressants After Kidney Transplant.
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Mitochondrial encephalomyopathy involves ophthalmology otorhinolaryngology neurology and their clinical features.