myoclonic epilepsy with ragged-red fibers (MERRF) syndrome

Epidemiology

• prevalence in the general population of Europe has been estimated at 0.9 in 100,000 individuals, but the disease seems to be more common in the USA
• patients usually present during adolescence or early adulthood

Pathology

• mitochondrial encephalomyopathy (red muscle pathology)

Genetics

• associated with defects in MT-ND5
• associated with defects in MT-TL1

Clinical manifestations

• myoclonic seizures
• may present with neurosensory deafness, optic atrophy, short stature, or peripheral neuropathy

Laboratory

• MT-ND5 gene mutation
• MT-TL1 gene mutation

Management

• specific treatment not available
• limited success in some clinical trials with
  • Coenzyme Q10
  • riboflavin
  • vitamin C
  • vitamin K

More general terms

• mitochondrial encephalomyopathy
• metabolic brain disease
• epilepsy
• lipid metabolism, inborn error; lipid storage disease; lipidosis