Myoclonic Epilepsy Associated with Ragged-Red Fibers (MERRF)

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Disease Ontology 12 DOID:310 OMIM 56 545000 KEGG 36 H01356 MeSH 43 D017243 NCIt 49 C84889 SNOMED-CT 67 230426003 ICD10 32 E88.42

MESH via Orphanet 44 D017243 ICD10 via Orphanet 33 G71.3 UMLS via Orphanet 72 C0162672 Orphanet 58 ORPHA551 MedGen 41 C0162672 SNOMED-CT via HPO 68 127324008 128613002 129565002 17450006 192992007 221360009 237836003 246545002 26544005 267581004 274523007 313307000 37356005 386806002 397790002 404062002 46720004 60342002 60700002 76976005 84757009 85102008 91175000 93163002 more UMLS 71 C0162672

Genetics Home Reference : ²⁵ Myoclonic epilepsy with ragged-red fibers (MERRF) is a disorder that affects many parts of the body, particularly the muscles and nervous system. In most cases, the signs and symptoms of this disorder appear during childhood or adolescence. The features of MERRF vary widely among affected individuals, even among members of the same family. MERRF is characterized by muscle twitches (myoclonus), weakness (myopathy), and progressive stiffness (spasticity). When the muscle cells of affected individuals are stained and viewed under a microscope, these cells usually appear abnormal. These abnormal muscle cells are called ragged-red fibers. Other features of MERRF include recurrent seizures (epilepsy), difficulty coordinating movements (ataxia), a loss of sensation in the extremities (peripheral neuropathy), and slow deterioration of intellectual function (dementia). People with this condition may also develop hearing loss or optic atrophy, which is the degeneration (atrophy) of nerve cells that carry visual information from the eyes to the brain. Affected individuals sometimes have short stature and a form of heart disease known as cardiomyopathy. Less commonly, people with MERRF develop fatty tumors, called lipomas, just under the surface of the skin.

MalaCards based summary : Myoclonic Epilepsy Associated with Ragged-Red Fibers, also known as merrf syndrome, is related to mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes and parkinson disease, mitochondrial. An important gene associated with Myoclonic Epilepsy Associated with Ragged-Red Fibers is MT-TK (Mitochondrially Encoded TRNA-Lys (AAA/G)), and among its related pathways/superpathways are Aminoacyl-tRNA biosynthesis and Oxidative phosphorylation. The drugs Coenzyme Q10 and Ubiquinone have been mentioned in the context of this disorder. Affiliated tissues include eye, brain and skin, and related phenotypes are sensorineural hearing impairment and myopathy

NIH Rare Diseases : ⁵² Myoclonic epilepsy with ragged red fibers (MERRF) is a multisystem disorder characterized by myoclonus , which is often the first symptom, followed by generalized epilepsy , ataxia , weakness, and dementia . Symptoms usually first appear in childhood or adolescence after normal early development. The features of MERRF vary widely from individual to individual, even within families. Other common findings include hearing loss , short stature , optic atrophy , and cardiomyopathy with Wolff-Parkinson-White (WPW) syndrome . The diagnosis is based on clinical features and a muscle biopsy finding of ragged red fibers (RRF). In over 80% of cases, MERRF is caused by mutations in the mitochondrial gene called MT-TK . Several other mitochondrial genes have also been reported to cause MERRF, but many of the individuals with mutations in these other genes have additional signs and symptoms. Seizures associated with MERRF are generally treated with conventional anticonvulsant therapy. Coenzyme Q10 and L-carnitine are often used with the hope of improving mitochondrial function.

KEGG : ³⁶ Myoclonic Epilepsy and Ragged-Red Fiber Disease (MERRF) is a mitochondrial encephalomyopathy characterized by myoclonic seizures, cerebellar ataxia, myopathy, and ragged-red fibers (RRFs) on muscle biopsy. RRFs are muscle fibers with subsarcolemmal mitochondria that stained red with Gomori trichrome stain. The MERRF syndrome is most commonly caused by the A8344G mutation in the mitochondrial tRNA Lys gene.

Wikipedia : ⁷⁴ MERRF syndrome (or myoclonic epilepsy with ragged red fibers) is a mitochondrial disease. It is... more...

More information from OMIM: 545000

GeneReviews: NBK1520

Clinical features from OMIM:

545000

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