MELAS Syndrome

MELAS (Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like Episodes) is a progressive and devastating condition that affects many of the body’s systems, particularly the brain (encephalopathy) and nervous system. The most characteristic symptoms of MELAS are recurring, stroke-like episodes in which severe, migraine-like headaches are followed by vomiting and seizures.

Repeated stroke-like episodes can progressively damage the brain, leading to vision loss, problems with movement, and dementia. Other symptoms include short stature, diabetes, exercise intolerance and hearing loss. Most people suffering from MELAS have an accumulation of lactic acid (lactic acidosis) in the blood which can lead to vomiting, abdominal pain, extreme tiredness, muscle weakness, and difficulty breathing. Elevated levels of lactic acid in the brain are considered to be part of the underlying causes that lead to stroke-like episodes and brain tissue damage. The maternally inherited multisystem disorder runs in families and manifests in both sexes. First signs and symptoms usually appear already in childhood. MELAS is associated with a shortened life-expectancy.

The MELAS syndrome is caused by a mutation in the mitochondrial genome leading to impaired function of the mitochondrial respiratory chain. Current treatment options are limited to symptomatic management of seizures, diabetes and other medical complications. There are no approved therapies available or in advanced clinical development to help people with MELAS.