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eRAM

encyclopedia of Rare Disease Annotation for Precision Medicine




Disease merrf
Comorbidity C0014544|epilepsy
Sentences 43
PubMedID- 24791085 It encompasses different diagnostic entities, and the common causes include lafora body disease [figure 1a and b], neuronal ceroid lipofuscinosis (ncl), unverricht-lundborg disease (uld), myoclonic epilepsy with ragged-red fiber (merrf) syndrome, sialidoses, dentato-rubro-pallidal atrophy, storage diseases, and some of the inborn errors of metabolism, among others.
PubMedID- 21424749 In the patients described here, cns involvement was similar to that observed in myoclonus epilepsy with ragged-red fiber (merrf) due to the accompanying cerebellar atrophy and epilepsy.
PubMedID- 23836506 Analysis for mtdna deletions, duplications, and depletion and screens for melas (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes), merrf (myoclonic epilepsy with ragged red fibers), and narp (neuropathy, ataxia, and retinitis pigmentosa) were negative.
PubMedID- 24584743 The 2 most significant examples of mt‐trna‐related cardiomyopathies are represented by melas (mitochondrial encephalomyopathy, lactic acidosis, and stroke‐like episodes), a major and well characterized mitochondrial disease caused by point mutations in mt‐trna‐leu (uur) genes, and merrf (myoclonic epilepsy with ragged red fibers), a major subgroup of the mitochondrial encephalomyopathies caused by a point mutation at position 8344 in the mt‐trnalys gene.
PubMedID- 24338029 It is known that the myoclonus epilepsy with ragged-red fibers (merrf) is characterized by cerebellar ataxia and myoclonus epilepsy, while that the mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (melas) is characterized by recurrent stroke-like episodes, migraine-like headaches, and elevated resting lactate blood level.
PubMedID- 23006856 We explored the feasibility of mitochondrial therapy using the cell-penetrating peptide pep-1 to transfer mitochondrial dna (mtdna) between cells and rescue a cybrid cell model of the mitochondrial disease myoclonic epilepsy with ragged-red fibres (merrf) syndrome.
PubMedID- 25356388 The inherited mitochondrial disorders, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (melas), myoclonic epilepsy with ragged red fibers (merrf), and neuropathy, ataxia, and retinitis pigmentosa (narp) were excluded, and genetic tests for the lipid storage disease, niemann pick type c (sequencing of npc1 and npc2), were normal.
PubMedID- 25667850 Besides lbd, they include unverricht–lundborg disease (uld), myoclonic epilepsy with ragged-red fibers (merrf), neuronal ceroid lipofuscinoses, sialidoses, and dentatorubral-pallidoluysian atrophy [2,3].
PubMedID- 25574211 Myoclonic epilepsy with ragged-red fibers (merrf) is a neurological disorder that is characterized by muscle twitches, weakness and progressive stiffness that affects numerous muscles of the body.
PubMedID- 24618073 There are a few cases of mitochondrial neuropathies due to a mtdna point mutation responsible for melas (mitochondrial encephalopathy, lactic acidosis, stroke-like episodes) or merrf (myoclonic epilepsy with ragged red fibers) phenotypes, but most cases are secondary to nuclear mutations with ensuing mitochondrial dysfunction, and usually associated with multiple small deletions of mtdna.
PubMedID- 22448145 For example, mutations in the mitochondrial genome have been found in a wide range of disorders including leber's hereditary optic neuropathy (lhon), neuropathy, ataxia and retinitis pigmentosa (narp), mitochondrial myopathy, encephalopathy, lactic acidosis and stroke (melas), myoclonic epilepsy associated with ragged red fibers (merrf), nonsyndromic sensorineural deafness (nssd), and kearns-sayre syndrome [1],[2].
PubMedID- PMC4428875 Their etiologies were confirmed by clinical features and mitochondrial gene sequencing: leber hereditary optic neuropathy (lhon) (56 patients, 52.8%), melas (33 patients, 31.1%), leigh disease (7 patients, 6.6%), myoclonic epilepsy with ragged red fibers (merrf) (7 patients, 6.6%), pearson syndrome (2 patients, 0.02%) and kearns-sayre syndrome (kss) (1 patient, 0.9%).
PubMedID- 20508802 Kearns-sayre syndrome, melas syndrome, mitochondrial myopathy, dad (diabetes mellitus and deafness), lhon (leber's hereditary optic neuropathy), leigh syndrome, narp (neuropathy, ataxia, retinitis pigmentosa, and ptosis), merrf (myoclonic epilepsy with ragged red fibers) syndrome, and mngie (myoneurogenic gastrointestinal encephalopathy) are all categorized as mitochondrial diseases.
PubMedID- 24523223 Atp = adenosine triphosphate; melas = mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes; merrf = myoclonic epilepsy with ragged red fibers; mnd = motor neuron disease; nadh = nicotinamide adenine dinucleotide; tbi = traumatic brain injury.
PubMedID- 21766266 Nearly all patients affected by myoclonic epilepsy with ragged-red fibres (merrf) harbour a mutation in the mitochondrial transfer rnalys gene.
PubMedID- 20739785 It encompasses different diagnostic entities and the common causes include lafora body disease, neuronal ceroid lipofuscinoses, unverricht-lundborg disease, myoclonic epilepsy with ragged-red fiber (merrf) syndrome, sialidoses, dentato-rubro-pallidal atrophy, storage diseases, and some of the inborn errors of metabolism, among others.
PubMedID- 22403016 2005), myoclonic epilepsy with ragged-red fibers (merrf)(durand-dubief et al.
PubMedID- 22969229 Results: twenty patients were sub-classified with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (melas), 8 with chronic progressive external ophthalmoplegia (cpeo), and 3 with myoclonus epilepsy associated with ragged-red fibers (merrf).
PubMedID- 25356405 Typical clinical features include mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (melas), myoclonus epilepsy associated with ragged-red fibers (merrf), leber's hereditary optic neuropathy (lhon), and chronic progressive external ophthalmoplegia (cpeo).2 although mtdna mutations or deletions are usually found in adults showing typical clinical findings, they account for only a minority of children with mrcd.
PubMedID- 25425607 While many patients do not fit into specific clinical syndromes, well known examples of mtdna diseases include midd (mitochondrially inherited diabetes and deafness) (van den ouweland et al., 1992), melas (mitochondrial myopathy, encephalomyopathy, lactic acidosis, stroke-like symptoms) (goto et al., 1990), mils (maternally inherited leigh's syndrome) (holt et al., 1990), merrf (myoclonic epilepsy with ragged red fibers) (wallace et al., 1988b) and lhon (leber's hereditary optic neuropathy) (wallace et al., 1988a; howell and mccullough, 1990; johns et al., 1992).
PubMedID- 23635963 Objectives: myoclonic epilepsy with ragged-red fibers (merrf) is a rare mitochondrial syndrome, mostly caused by the 8344a>g mitochondrial dna mutation.
PubMedID- 23390135 We have explored the impact of two disease-causing mutations [m.3243a>g myopathy, encephalopathy, lactic acidosis and stroke-like syndrome (melas) and m.8344a>g myoclonic epilepsy associated with ragged-red fibers (merrf)] on mtdna amounts in human oocytes and day 4-5 preimplantation embryos.
PubMedID- 20976001 One example is the merrf-syndrome (myoclonic epilepsy with ragged-red fibers, mim 545000), which is characterized by myoclonic seizures, ataxia, dementia, muscle weakness and accumulations of structurally abnormal mitochondria in the skeletal muscle [2].
PubMedID- 22931524 Twelve patients had a syndromic mitochondrial disorder (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (melas), myoclonic epilepsy with ragged red fibers (merrf), neuropathy, ataxia, and retinitis pigmentosa (narp), progressive external ophthalmoplegia (peo), kearns-sayre syndrome (kss)) and seven patients had a non-syndromic mitochondrial disorder.
PubMedID- 20610441 Background: myoclonic epilepsy with ragged-red fibres (merrf) and mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (melas) are established phenotypes of mitochondrial encephalomyopathy.
PubMedID- 20075606 Found an a to g transition at np 8344 in the trnalys gene, in most patients with myoclonus epilepsy associated with ragged-red fibers (merrf),125) another major clinical subgroup of the mitochondrial encephalomyopathies.
PubMedID- 22354625 Myoclonic epilepsy with ragged-red fibers (merrf) is a mitochondrial disease usually caused by point mutations in transfer rna genes encoded by mitochondrial dna.
PubMedID- 24731735 Rare mutations in mitochondrial dna (mtdna) give rise to a spectrum of diseases, including leber’s hereditary optic neuropathy (lhon), myoclonic epilepsy with ragged red fibers (merrf), maternally inherited diabetes and deafness (midd), and prostate cancer[2].
PubMedID- 22548174 [39] reported the a8344g transition mutation in the trnalys gene of mtdna, characteristic for the maternally inherited merrf syndrome (myoclonic epilepsy with ragged red fibers) in extraocular muscle from individuals aged 67–89 years old.
PubMedID- 22761564 For example, the pathogenesis of certain mitochondrial diseases caused by mtdna mutations (e.g., melas, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome; merrf, myoclonic epilepsy with ragged red fibers syndrome) is not well understood.
PubMedID- 23182644 The other common mtdna change, the a8344g “merrf” (myoclonic epilepsy with ragged red fibers) mutation, showed the same frequency in the two groups.
PubMedID- 26001801 Based on the neuromuscular phenotype and genotype, the patients were grouped: (a) cpeo/kss (n = 33); (b) melas/-like (n = 11); c) myoclonic epilepsy with ragged-red fibers (merrf) (n = 3) and d) other non-specific mm forms (n = 17).
PubMedID- 22715922 Similarly, mutations in mitochondrial tdna genes encoding trnaphe, trnaleu, trnaser, trnahis and trnalys, which affect the accuracy and/or efficiency of translation, cause myopathy, encephalopathy, lactic acidosis, stroke-like episodes or myoclonic epilepsy with ragged-red fibers (melas/merrf syndromes) [16-18], indicating that mitochondria are particularly sensitive to gene translation fidelity and efficiency.
PubMedID- 24606795 There are several diseases that have a mitochondrial origin such as chronic progressive external ophthalmoplegia (cpeo) and the kearns- sayre syndrome (kss), myoclonic epilepsy with ragged-red fibers (merrf), mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (melas), leber's hereditary optic neuropathy (lhon), the syndrome of neurogenic muscle weakness, ataxia and retinitis pigmentosa (narp), and leigh's syndrome.
PubMedID- 22848783 Myoclonic epilepsy with ragged red fibers (merrf) is a rare syndrome characterized by myoclonus, muscle weakness, cerebellar ataxia, heart block, and dementia.
PubMedID- 24024028 myoclonic epilepsy with ragged red fibers is an example of a mitochondrial disease that presents with multiple neurologic signs in addition to myoclonic epilepsy, including deafness, myopathy, optic atrophy, and cerebellar ataxia.
PubMedID- 21656172 Examples of this phenomenon include leber’s optic atrophy, myoclonic epilepsy with ragged red fibers (merrf) syndrome or focal segmental glomerulosclerosis (fsgs) related to trnaleu mutations.
PubMedID- 22742457 Myoclonus epilepsy with ragged-red fibers (merrf) syndrome is a mitochondrial disease inherited through the maternal lineage.
PubMedID- 22294875 Other examples of known mitochondrial diseases include myoclonic epilepsy with ragged red fibers (merrf) and the disorder known as mitochondria encephalomyopathy, lactic acidosis, and stroke-like episodes (melas) (summarized by wallace [37, 38]).
PubMedID- 21890497 A mutation in trna(lys) that causes myoclonic epilepsy with ragged-red fibers (merrf) is also reported to prevent modification of the wobble u.
PubMedID- 23304257 Diseases such as kearns-sayre syndrome, pearson's syndrome, and progressive external ophthalmoplegia are caused by large-scale rearrangement of mtdna, while diseases such as melas syndrome, leber's hereditary optic neuropathy, and myoclonic epilepsy with ragged red fibers are caused by point mutations in mtdna [43].
PubMedID- 25667885 In exceptionally severe progression of cognitive or visual symptoms, lafora's disease, myoclonic epilepsy with ragged red fibers (merrf), neuronal ceroid lipofuscinoses (ncl), and sialidoses should be considered [2].
PubMedID- 22962564 merrf syndrome (myoclonic epilepsy with ragged red fibers) is a mitochondrial encephalomyopathy, characterized by myoclonic seizu-res in combination, sometimes, sensorineural deafness, optic atrophy, short stature, or peripheral neuropathy.

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