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Medical Author:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Medical Editor:

Frederick Hecht, MD, FAAP, FACMG

Frederick Hecht, MD, FAAP, FACMG

Frederick Hecht, MD, lives in Scottsdale, Arizona. Dr. Hecht is a Pediatrician and Medical Geneticist and is certified by both the American Boards of Pediatrics and Medical Genetics. Dr. Hecht was born and raised in Baltimore and attended Dartmouth College in Hanover, N.H. and the Sorbonne at the University of Paris receiving his BA degree cum laude with distinction from Dartmouth.

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In this Article

• What is MELAS?
• What causes MELAS?
• What are the symptoms of MELAS?
• How is MELAS diagnosed?
• When do people with MELAS develop symptoms?
• How is MELAS treated?
• Are there other mitochondrial diseases?
• MELAS Syndrome Index

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.

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.

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.

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

• An important eye disease called Leber hereditary optic atrophy ;
• A type of epilepsy called MERRF which stands for Myoclonus Epilepsy with Ragged Red Fibers; and
• A neuromuscular disease called the Kearns-Sayre syndrome .

MELAS and all other mitochondrial diseases were entirely enigmatic before it was discovered that they were due to mutations not in regular chromosomes but in the chromosome of the mitochondria.