Slideshows Images Quizzes

Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. See additional information.

MELAS Syndrome

What is MELAS?

MELAS is a rare genetic disorder which results in stroke and dementia. MELAS is an abbreviation that stands for Mitochondrial Encephalopathy, Lactic acidosis, and Stroke-like episodes.

What causes MELAS?

MELAS syndrome is caused by mutations in the genetic material (DNA) in the mitochondria. While most of our DNA is in the chromosomes in the cell nucleus, some of our DNA is in another important structure called the mitochondrion (plural: mitochondria).

The mitochondria are located outside the nucleus in the cell's cytoplasm. Each mitochondrion has a chromosome made of DNA that is quite different from the better known chromosomes in the nucleus. The mitochondrial chromosome is much smaller; it is round (whereas the chromosomes in the nucleus are normally shaped like rods); there are many copies of the mitochondrial chromosome in every cell; and no matter whether we are male or female, we inherit all of our mitochondrial chromosome from our mother.

Much of the DNA in our mitochondria is used to manufacture proteins involved in the key function of mitochondria -- to produce energy and power the cells in our body.

What are the symptoms of MELAS?

As a result of the disturbed function of their cells' mitochondria, patients with MELAS develop

How is MELAS diagnosed?

The diagnosis of MELAS is usually suspected on clinical grounds. However, confirmation of the diagnosis usually requires a muscle or brain biopsy. The muscle biopsy shows characteristic ragged red fibers; a brain biopsy shows stroke-like changes.

When do people with MELAS develop symptoms?

MELAS can affect people at very different times in life, ranging from age 4 to age 40 or more. However, most patients with MELAS syndrome show symptoms before they are 20 years old.

How is MELAS treated?

There is no known treatment for the underlying disease, which is progressive and fatal. Patients are managed according to what areas of the body are affected at a particular time. antioxidants and vitamins have been used, but there have been no consistent successes reported.

Are there other mitochondrial diseases?

Yes, mutations (genetic changes) in the mitochondrial chromosome are responsible for a number of other disorders aside from MELAS such as:

MELAS and all other mitochondrial diseases were not well understood before it was discovered that they were due to mutations in the chromosomes of the mitochondria.

QUESTION

The abbreviated term ADHD denotes the condition commonly known as: See Answer

Health Solutions From Our Sponsors

References
Medically reviewed by Joseph Carcione, DO; American Board of Psychiatry and Neurology

REFERENCE:

"Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes"
National Institutes of Health
CONTINUE SCROLLING FOR RELATED SLIDESHOW

Health Solutions From Our Sponsors