MERRF syndrome

MERRF syndrome (or Myoclonic Epilepsy with Ragged Red Fibers) is a mitochondrial disease.

Presentation
It involves the following characteristics:


 * progressive myoclonic epilepsy
 * clumps of diseased mitochondria accumulate in the subsarcolemmal region of the muscle fiber and appear as "ragged-red fibers" when muscle is stained with modified Gomori trichrome stain
 * short stature

Causes
The MERRF syndrome is caused by a maternally-inherited mutation at position 8344 in the mitochondrial genome. This point mutation disrupts the mitochondrial gene for tRNA-Lys and so disrupts synthesis of proteins essential for oxidative phosphorylation.

Genes involved include, , MT-TH, , , and.