mitochondrial encephalomyopathy, lactic acidosis and strokes
MELAS is maternally inherited neurodegenerative disorder. The clinical features become more severe with age.
The features of MELAS are:
- lactic acidosis
- stroke-like episodes
- occasionally, cardiomyopathy
Investigations should include a muscle biopsy to demonstrate fibres with abnormal mitochondria. The cerebrospinal fluid lactate level is elevated.
This neurological disease is caused by a maternally- inherited mutation at position 3243 in the mitochondrial genome. This point mutation disrupts one of the mitochondrial genes for tRNA-Leu and so disrupts synthesis of proteins essential for oxidative phosphorylation.
Last reviewed 09/2021