MERRF syndrome (or myoclonic epilepsy with ragged red fibers) is a mitochondrial disease. It is extremely rare, and has varying degrees of expressivity owing to heteroplasmy.[1] MERRF syndrome affects different parts of the body, particularly the muscles and nervous system.[2] The signs and symptoms of this disorder appear at an early age, generally childhood or adolescence. The causes of MERRF syndrome are difficult to determine, but because it is a mitochondrial disorder, it can be caused by the mutation of nuclear DNA or mitochondrial DNA.[3] The classification of this disease varies from patient to patient, since many individuals do not fall into one specific disease category. The primary features displayed on a person with MERRF include myoclonus, seizures, cerebellar ataxia, myopathy,[3] and ragged red fibers (RRF) on muscle biopsy, leading to the disease's name. Secondary features include dementia, optic atrophy, bilateral deafness, peripheral neuropathy, spasticity, or multiple lipomata. Mitochondrial disorders, including MERRFS, may present at any age.[4]
^Gene Reviews: MERRF
^DiMauro, Salvatore; Hirano, Michio (1993). "MERRF". In Adam, Margaret P.; Ardinger, Holly H.; Pagon, Roberta A.; Wallace, Stephanie E.; Bean, Lora J.H.; Mefford, Heather C.; Stephens, Karen; Amemiya, Anne; Ledbetter, Nikki (eds.). GeneReviews. Seattle (WA): University of Washington, Seattle. PMID 20301693.
^ abChinnery, Patrick F. (1993). "Mitochondrial Disorders Overview". In Adam, Margaret P.; Ardinger, Holly H.; Pagon, Roberta A.; Wallace, Stephanie E.; Bean, Lora J.H.; Mefford, Heather C.; Stephens, Karen; Amemiya, Anne; Ledbetter, Nikki (eds.). GeneReviews. Seattle (WA): University of Washington, Seattle. PMID 20301403.
^"Mitochondrial myopathies: Clinical features and diagnosis". www.uptodate.com. Retrieved 2017-11-07.
MERRFsyndrome (or myoclonic epilepsy with ragged red fibers) is a mitochondrial disease. It is extremely rare, and has varying degrees of expressivity...
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fibers (MERRFsyndrome), Lafora disease, neuronal ceroid lipofuscinosis, and sialidosis. Temporal lobe epilepsy (TLE) is not a classic syndrome but mentioned...
associated with a mitochondrial disease. MELAS syndrome Examples include MELAS syndrome and MERRFsyndrome. These conditions can sometimes present together...
difficulties until they have reached adulthood. Another example is MERRFsyndrome (or Myoclonic Epilepsy with Ragged Red Fibers). In MELAS, heteroplasmy...
rearrangements, whereas other diseases such as MELAS syndrome, Leber's hereditary optic neuropathy, MERRFsyndrome, and others are due to point mutations in mtDNA...
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fatal. MERRFsyndrome is also known as myoclonic epilepsy with ragged-red fibers. This rare inherited disorder affects muscles cells. Features of MERRF, along...
mitochondrial tRNAs can be responsible for severe diseases like the MELAS and MERRFsyndromes. Mutations in nuclear genes that encode proteins that mitochondria...
in the brain becomes disordered leading to seizures. It is also found in MERRF (Myoclonic Epilepsy with Ragged Red Fibers), a rare mitochondrial encephalomyopathy...
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