{"Name":"MERRF syndrome","DiseaseID__c":"GARD:0007144","id":7144,"encodedName":"merrf-syndrome","IsDeleted":false,"Disease_Name_Full__c":"MERRF syndrome","Xref_IDs__c":"423022830; 68448003; C0162672; C84889; D017243; DOID:310; E88.42; MEDGEN:56486; MONDO:0010790; NBK1520; OMIM:545000; ORPHA:551","USA_Estimate__c":null,"No_of_Specialist_Tagsa__c":8,"No_of_ClinGen_records__c":0,"No_of_GeneReviews__c":1,"No_of_HHS_records__c":2,"World_Estimate__c":null,"No_of_HRSA_records__c":0,"Evidence_Based_Score__c":4,"No_of_Disease_Descriptions__c":4,"Disease_Characteristics_Score__c":8,"No_of_Age_at_Onset__c":2,"Description_Source__c":"MONDO:0010790","Disease_Description__c":"A condition that can be caused by mutation(s) in more than one mitochondrial gene. It is characterized by myoclonic epilepsy and ragged-red fibers present on muscle biopsy.","GARD_Name__c":"MERRF syndrome","GARD_Synonym__c":"fukuhara syndrome; merrf; merrf - myoclonic epilepsy with ragged red fibers; myoclonic epilepsy - ragged red fibers; myoclonic epilepsy - ragged red fibres; myoclonic epilepsy associated with ragged-red fibers; myoclonic epilepsy with ragged red fibers; myoclonus epilepsy and ragged red fibers; myoclonus epilepsy and ragged red fibres; myoclonus epilepsy associated with ragged-red fibers; myoclonus epilepsy associated with ragged-red fibres; myoclonus with epilepsy and with ragged red fibers; myoclonus with epilepsy and with ragged red fibers (merrf syndrome); myoclonus with epilepsy and with ragged red fibres; myoclonus with epilepsy and with ragged red fibres (merrf syndrome); myoclonus with epilepsy with ragged red fibers; myoencephalopathy ragged-red fiber disease","Curated_Disease_Description_Source__c":"GARD:0007144","Curated_Disease_Description__c":"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.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":null,"Age_at_Onset_Snippet_Text__c":"as a Child and as an Adult","SourceID__c":"ORPHA:551","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0010790","ORPHANET_ID__c":"ORPHA:551","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Merrf","Spanish_Description_Source__c":"ORPHA:551","Spanish_Description__c":"Es un trastorno poco frecuente de la fosforilación oxidativa mitocondrial caracterizado por crisis mioclónicas, ataxia, epilepsia generalizada, debilidad muscular y fibras rojas rasgadas en la biopsia muscular.","Spanish_Disease_Name__c":"merrf","Spanish_GARD_Synonym__c":"epilepsia mioclónica asociada con fibras rojas rasgadas; síndrome de fukuhara","Category_Linearization__c":"ORPHA:98006","icd10_id__c":null,"mesh_id__c":null,"omim_id__c":null,"snomed_id__c":null,"umls_id__c":null,"GARD_Disease__c":[{"Curated_Disease_Description__c":"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.","Curated_Disease_Description_Source__c":"GARD:0007144","GARD_Synonym__c":"fukuhara syndrome; merrf; merrf - myoclonic epilepsy with ragged red fibers; myoclonic epilepsy - ragged red fibers; myoclonic epilepsy - ragged red fibres; myoclonic epilepsy associated with ragged-red fibers; myoclonic epilepsy with ragged red fibers; myoclonus epilepsy and ragged red fibers; myoclonus epilepsy and ragged red fibres; myoclonus epilepsy associated with ragged-red fibers; myoclonus epilepsy associated with ragged-red fibres; myoclonus with epilepsy and with ragged red fibers; myoclonus with epilepsy and with ragged red fibers (merrf syndrome); myoclonus with epilepsy and with ragged red fibres; myoclonus with epilepsy and with ragged red fibres (merrf syndrome); myoclonus with epilepsy with ragged red fibers; myoencephalopathy ragged-red fiber disease","Name":"MERRF syndrome","estimateUsa":""}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"Australian Mitochondrial Disease Foundation","Website__c":"https://www.amdf.org.au/"},{"Account_Name__c":"Childhood Dementia Initiative","Website__c":"https://www.childhooddementia.org/"},{"Account_Name__c":"United Mitochondrial Disease Foundation","Website__c":"https://www.umdf.org"},{"Account_Name__c":"MitoAction","Website__c":"https://www.mitoaction.org/"},{"Account_Name__c":"Muscular Dystrophy Association","Website__c":"https://www.mda.org"}],"GARD_Disease_Tag__c":[{"Tag_Name__c":"Genetics","Tag_Category__c":"Cause;Disease Category;Specialist","category_description":"Genetic diseases affect the DNA, or genetic instructions, which directs how tissues, organs, and body systems function.","curated_tag_name":"Genetic diseases"},{"Tag_Name__c":"Cardiology","Tag_Category__c":"Specialist"},{"Tag_Name__c":"Neurology","Tag_Category__c":"Disease Category;Specialist","category_description":"Neurological diseases affect the brain, spinal cord, cranial nerves, autonomic nerves, or other peripheral nerves.","curated_tag_name":"Neurological diseases"},{"Tag_Name__c":"Ophthalmology","Tag_Category__c":"Specialist"},{"Tag_Name__c":"Inborn Errors of Metabolism","Tag_Category__c":"Cause;Disease Category","category_description":"Inherited metabolic diseases, or inborn errors of metabolism, are a group of genetic diseases that affect the ability of the body's cells to convert food into energy.","curated_tag_name":"Inherited metabolic diseases"},{"Tag_Name__c":"Mitochondrial","Tag_Category__c":"Account;Cause;Disease Category","category_description":"Mitochondrial diseases are a group of genetic diseases that affect the ability of the body's cells to make energy.","curated_tag_name":"Mitochondrial diseases"},{"Tag_Name__c":"Peripheral Neuropathy","Tag_Category__c":"Account","curated_tag_name":"Peripheral neuropathy"},{"Tag_Name__c":"Epilepsy","Tag_Category__c":"Account;Specialist","curated_tag_name":"Epilepsy"},{"Tag_Name__c":"Cardiomyopathy","Tag_Category__c":"Account","curated_tag_name":"Cardiomyopathy"},{"Tag_Name__c":"Neuro-Ophthalmology","Tag_Category__c":"Specialist","curated_tag_name":"Neuro-ophthalmic diseases"},{"Tag_Name__c":"Neuromuscular medicine","Tag_Category__c":"Specialist","curated_tag_name":"Neuromuscular medicine"},{"Tag_Name__c":"Pediatrics","Tag_Category__c":"Specialist"}],"Age_At_Onset__c":[{"Age_At_Onset__c":"Adult","Provided_By__c":"ORPHA:551"},{"Age_At_Onset__c":"Childhood","Provided_By__c":"ORPHA:551"}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C0162672"}],"External_Identifier_Disease__c":[{"URL__c":"https://www.ncbi.nlm.nih.gov/books/NBK1520","Source__c":"Gene Review","Xref__c":"NBK1520"},{"URL__c":"https://www.ncbi.nlm.nih.gov/books/NBK1224","Xref__c":"NBK1224"},{"URL__c":"https://www.omim.org/entry/545000","Source__c":"C0162672; MONDO:0010790; ORPHA:551","Xref__c":"OMIM:545000"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=68448003","Source__c":"MONDO:0010790","Xref__c":"68448003"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C0162672","Source__c":"C0162672","Xref__c":"C0162672"},{"URL__c":"http://purl.bioontology.org/ontology/ICD10CM/E88.42","Source__c":"MONDO:0010790","Xref__c":"E88.42"},{"URL__c":"https://www.ebi.ac.uk/ols4/ontologies/doid/classes?obo_id=DOID%3A310","Source__c":"MONDO:0010790","Xref__c":"DOID:310"},{"URL__c":"https://www.orpha.net/en/disease/detail/551","Source__c":"C0162672; MONDO:0010790; ORPHA:551","Xref__c":"ORPHA:551"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=56486","Source__c":"C0162672","Xref__c":"MEDGEN:56486"},{"URL__c":"https://evsexplore.semantics.cancer.gov/evsexplore/concept/ncit/C84889","Source__c":"C0162672; MONDO:0010790","Xref__c":"C84889"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C017243","Source__c":"C0162672; MONDO:0010790","Xref__c":"D017243"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=230426003","Source__c":"C0162672","Xref__c":"230426003"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0010790","Source__c":"GARD:0007144","Xref__c":"MONDO:0010790"},{"URL__c":"https://medlineplus.gov/genetics/condition/myoclonic-epilepsy-with-ragged-red-fibers","Source__c":"GARD:0007144","Xref__c":"https://medlineplus.gov/genetics/condition/myoclonic-epilepsy-with-ragged-red-fibers"},{"URL__c":"https://secure.ssa.gov/apps10/poms.nsf/lnx/0423022830","Xref__c":"423022830"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"MT-TP","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TI","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TF","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TL1","GHR_URL__c":"https://medlineplus.gov/genetics/gene/mt-tl1","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TK","GHR_URL__c":"https://medlineplus.gov/genetics/gene/mt-tk","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TS1","GHR_URL__c":"https://medlineplus.gov/genetics/gene/mt-ts1","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TS2","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true},{"GeneSymbol__c":"MT-TH","GHR_URL__c":"https://medlineplus.gov/genetics/gene/mt-th","Gene_Type__c":"non-coding RNA","Causal_Gene__c":true}],"Inheritance__c":["Mitochondrial inheritance"],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003200","HPO_Synonym__c":"Mitochondrial proliferation in muscle tissue; Ragged red muscle fibers; Ragged-red fibers","HPO_Name__c":"Ragged-red muscle fibers","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001251","HPO_Synonym__c":"Cerebellar ataxia","HPO_Name__c":"Ataxia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Abnormal results of investigations using electromyography (EMG).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003457","HPO_Synonym__c":"Abnormal electromyography finding; Abnormal EMG; Electromyogram abnormal; EMG abnormalities","HPO_Name__c":"EMG abnormality","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Procedure_EMG"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The presence of multiple lipomas (a type of benign tissue made of fatty tissue).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001012","HPO_Synonym__c":"Lipomata; Multiple fatty lumps","HPO_Name__c":"Multiple lipomas","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002123","HPO_Synonym__c":"Generalised epileptic myoclonus; Generalised myoclonic seizure; Generalized epileptic myoclonus; Generalized myoclonic seizures; Myoclonus seizures","HPO_Name__c":"Generalized myoclonic seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"An abnormality of movement with a neurological basis characterized by changes in coordination and speed of voluntary movements.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0100022","HPO_Synonym__c":"Abnormality of movement; Movement disorder; Unusual movement","HPO_Name__c":"Abnormality of movement","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A height below that which is expected according to age and sex norms. Although there is no universally accepted definition of short stature, many refer to \\\"short stature\\\" as height more than 2 standard deviations below the mean for age and sex (or below the 3rd percentile for age and sex dependent norms).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0004322","HPO_Synonym__c":"Decreased body height; Height less than 3rd percentile; Short stature; Small stature; Stature below 3rd percentile","HPO_Name__c":"Short stature","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0100543","HPO_Synonym__c":"Abnormality of cognition; Cognitive abnormality; Cognitive defects; Cognitive deficits; Cognitive impairment; Intellectual impairment","HPO_Name__c":"Cognitive impairment","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000407","HPO_Synonym__c":"Hearing loss, sensorineural; Sensorineural deafness; Sensorineural hearing loss","HPO_Name__c":"Sensorineural hearing impairment","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000648","HPO_Synonym__c":"Optic nerve atrophy; Optic-nerve degeneration","HPO_Name__c":"Optic atrophy","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:551","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A disorder of muscle unrelated to impairment of innervation or neuromuscular junction.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003198","HPO_Synonym__c":"Muscle tissue disease; Myopathic changes","HPO_Name__c":"Myopathy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics","Inborn Errors of Metabolism","Mitochondrial"],"Disease Category":["Genetics","Neurology","Inborn Errors of Metabolism","Mitochondrial"],"Specialist":["Genetics","Cardiology","Neurology","Ophthalmology","Epilepsy","Neuro-Ophthalmology","Neuromuscular medicine","Pediatrics"],"Account":["Mitochondrial","Peripheral Neuropathy","Epilepsy","Cardiomyopathy"]},"synonyms":["fukuhara syndrome"," merrf"," merrf - myoclonic epilepsy with ragged red fibers"," myoclonic epilepsy - ragged red fibers"," myoclonic epilepsy - ragged red fibres"," myoclonic epilepsy associated with ragged-red fibers"," myoclonic epilepsy with ragged red fibers"," myoclonus epilepsy and ragged red fibers"," myoclonus epilepsy and ragged red fibres"," myoclonus epilepsy associated with ragged-red fibers"," myoclonus epilepsy associated with ragged-red fibres"," myoclonus with epilepsy and with ragged red fibers"," myoclonus with epilepsy and with ragged red fibers (merrf syndrome)"," myoclonus with epilepsy and with ragged red fibres"," myoclonus with epilepsy and with ragged red fibres (merrf syndrome)"," myoclonus with epilepsy with ragged red fibers"," myoencephalopathy ragged-red fiber disease"]}