Mitochondrial myopathy, encephalopathy,<unk><unk> ,<unk> -like<unk> , abbreviated to MELAS is one of the family of mitochondrial cytopathies, which also include MERRF, and Leber's Hereditary Optic Atrophy.  A feature of these diseases is that they are caused by defects in the mitochondrial genome which is inherited purely from the female parent.  The disease can manifest in both sexes.
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes
Mitochondrial neurogastrointestinal encephalopathy syndrome
Woodhouse-Sakati syndrome
Transmissible spongiform encephalopathy
Hashimoto's encephalopathy
Feline spongiform encephalopathy
Bickers-Adams syndrome
Waterhouse–Friderichsen syndrome