Myoclonic epilepsy with ragged-red fibers
Last updated 20 Apr 2021
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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.
Description
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 characterised 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 tumours, called lipomas, just under the surface of the skin.
Inheritance patterns
The source lists the following possible inheritance patterns: mitochondrial. More than one pattern can apply in different cases.
Related genes
Other names
Fukuhara disease
MERRF
MERRF syndrome
Myoclonic epilepsy associated with ragged-red fibers
Myoencephalopathy ragged-red fiber disease
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Further reading and references
- Myoclonic epilepsy with ragged-red fibers; MedlinePlus, National Library of Medicine.
- Blakely EL, Trip SA, Swalwell H, He L, Wren DR, Rich P, Turnbull DM, Omer SE, Taylor RW. A new mitochondrial transfer RNAPro gene mutation associated with myoclonic epilepsy with ragged-red fibers and other neurological features. Arch Neurol. 2009 Mar;66(3):399-402. doi: 10.1001/archneurol.2008.576.
- Cardaioli E, Malfatti E, Da Pozzo P, Gallus GN, Carluccio MA, Rufa A, Volpi N, Dotti MT, Federico A. Progressive mitochondrial myopathy, deafness, and sporadic seizures associated with a novel mutation in the mitochondrial tRNASer(AGY) gene. J Neurol Sci. 2011 Apr 15;303(1-2):142-5. doi: 10.1016/j.jns.2010.12.020. Epub 2011 Jan 22.
- del Mar O'Callaghan M, Emperador S, Lopez-Gallardo E, Jou C, Bujan N, Montero R, Garcia-Cazorla A, Gonzaga D, Ferrer I, Briones P, Ruiz-Pesini E, Pineda M, Artuch R, Montoya J. New mitochondrial DNA mutations in tRNA associated with three severe encephalopamyopathic phenotypes: neonatal, infantile, and childhood onset. Neurogenetics. 2012 Aug;13(3):245-50. doi: 10.1007/s10048-012-0322-0. Epub 2012 May 26.
- Deschauer M, Muller T, Wieser T, Schulte-Mattler W, Kornhuber M, Zierz S. Hearing impairment is common in various phenotypes of the mitochondrial DNA A3243G mutation. Arch Neurol. 2001 Nov;58(11):1885-8. doi: 10.1001/archneur.58.11.1885.
- DiMauro S. Mitochondrial diseases. Biochim Biophys Acta. 2004 Jul 23;1658(1-2):80-8. doi: 10.1016/j.bbabio.2004.03.014.
- Mancuso M, Filosto M, Mootha VK, Rocchi A, Pistolesi S, Murri L, DiMauro S, Siciliano G. A novel mitochondrial tRNAPhe mutation causes MERRF syndrome. Neurology. 2004 Jun 8;62(11):2119-21. doi: 10.1212/01.wnl.0000127608.48406.f1.
- Mancuso M, Petrozzi L, Filosto M, Nesti C, Rocchi A, Choub A, Pistolesi S, Massetani R, Fontanini G, Siciliano G. MERRF syndrome without ragged-red fibers: the need for molecular diagnosis. Biochem Biophys Res Commun. 2007 Mar 23;354(4):1058-60. doi: 10.1016/j.bbrc.2007.01.099. Epub 2007 Jan 26.
- Melone MA, Tessa A, Petrini S, Lus G, Sampaolo S, di Fede G, Santorelli FM, Cotrufo R. Revelation of a new mitochondrial DNA mutation (G12147A) in a MELAS/MERFF phenotype. Arch Neurol. 2004 Feb;61(2):269-72. doi: 10.1001/archneur.61.2.269.
- Moraes CT, Ciacci F, Bonilla E, Jansen C, Hirano M, Rao N, Lovelace RE, Rowland LP, Schon EA, DiMauro S. Two novel pathogenic mitochondrial DNA mutations affecting organelle number and protein synthesis. Is the tRNA(Leu(UUR)) gene an etiologic hot spot? J Clin Invest. 1993 Dec;92(6):2906-15. doi: 10.1172/JCI116913.
- Nakamura M, Nakano S, Goto Y, Ozawa M, Nagahama Y, Fukuyama H, Akiguchi I, Kaji R, Kimura J. A novel point mutation in the mitochondrial tRNA(Ser(UCN)) gene detected in a family with MERRF/MELAS overlap syndrome. Biochem Biophys Res Commun. 1995 Sep 5;214(1):86-93. doi: 10.1006/bbrc.1995.2260.
- Pulkes T, Liolitsa D, Eunson LH, Rose M, Nelson IP, Rahman S, Poulton J, Marchington DR, Landon DN, Debono AG, Morgan-Hughes JA, Hanna MG. New phenotypic diversity associated with the mitochondrial tRNA(SerUCN) gene mutation. Neuromuscul Disord. 2005 May;15(5):364-71. doi: 10.1016/j.nmd.2005.01.006.
- Taylor RW, Schaefer AM, McDonnell MT, Petty RK, Thomas AM, Blakely EL, Hayes CM, McFarland R, Turnbull DM. Catastrophic presentation of mitochondrial disease due to a mutation in the tRNA(His) gene. Neurology. 2004 Apr 27;62(8):1420-3. doi: 10.1212/01.wnl.0000120667.77372.46.
- Teive HA, Munhoz RP, Muzzio JA, Scola RH, Kay CK, Raskin S, Werneck LC, Bruhn H. Cerebellar ataxia, myoclonus, cervical lipomas, and MERRF syndrome. Case report. Mov Disord. 2008 Jun 15;23(8):1191-2. doi: 10.1002/mds.21990. No abstract available.
- Tuppen HA, Naess K, Kennaway NG, Al-Dosary M, Lesko N, Yarham JW, Bruhn H, Wibom R, Nennesmo I, Weleber RG, Blakely EL, Taylor RW, McFarland R. Mutations in the mitochondrial tRNA Ser(AGY) gene are associated with deafness, retinal degeneration, myopathy and epilepsy. Eur J Hum Genet. 2012 Aug;20(8):897-904. doi: 10.1038/ejhg.2012.44. Epub 2012 Feb 29.
- Velez-Bartolomei F, Lee C, Enns G. MERRF. 2003 Jun 3 [updated 2021 Jan 7]. In: Adam MP, Bick S, Mirzaa GM, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2026. Available from http://www.ncbi.nlm.nih.gov/books/NBK1520/
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