{"Name":"Mitochondrial complex II deficiency, nuclear type 1","DiseaseID__c":"GARD:0005053","id":5053,"encodedName":"mitochondrial-complex-ii-deficiency-nuclear-type-1","IsDeleted":false,"Disease_Name_Full__c":"Mitochondrial complex II deficiency, nuclear type 1","Xref_IDs__c":"124165006; C565375; C5700310; DOID:0060537; MEDGEN:1814582; MONDO:0100294; OMIM:252011; ORPHA:3208","USA_Estimate__c":"1,000","No_of_Specialist_Tagsa__c":5,"No_of_ClinGen_records__c":0,"No_of_GeneReviews__c":0,"No_of_HHS_records__c":0,"World_Estimate__c":"1 to 8,000","No_of_HRSA_records__c":0,"Evidence_Based_Score__c":0,"No_of_Disease_Descriptions__c":4,"Disease_Characteristics_Score__c":8,"No_of_Age_at_Onset__c":2,"Description_Source__c":"MONDO:0100294","Disease_Description__c":"Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The signs and symptoms of mitochondrial complex II deficiency can vary greatly from severe life-threatening symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by mutations in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying gene mutations cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency gene mutation carriers may be at an increased risk for certain cancers.","GARD_Name__c":"Mitochondrial complex II deficiency, nuclear type 1","GARD_Synonym__c":"isolated mitochondrial respiratory chain complex ii deficiency; isolated succinate dehydrogenase deficiency; isolated succinate-coenzyme q reductase deficiency; isolated succinate-coq reductase deficiency; isolated succinate-ubiquinone reductase deficiency; mitochondrial complex ii deficiency; mitochondrial respiratory chain complex ii deficiency; mitochondrial respiratory chain complex ii deficiency, sdha-related; mitochondrial respiratory chain complex ii deficiency, sdhaf1-related; succinate coq reductase deficiency","Curated_Disease_Description_Source__c":"GARD:0005053","Curated_Disease_Description__c":"Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The symptoms can vary greatly from serious symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by genetic changes in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying genetic changes cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency genetic change carriers may be at an increased risk for certain cancers.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":"1,000","Age_at_Onset_Snippet_Text__c":"as a Newborn and as an Infant","SourceID__c":"ORPHA:3208","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0100294","ORPHANET_ID__c":"ORPHA:3208","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Deficiencia aislada de succinato-coq reductasa","Spanish_Description_Source__c":null,"Spanish_Description__c":null,"Spanish_Disease_Name__c":"deficiencia aislada de succinato-coq reductasa","Spanish_GARD_Synonym__c":"deficiencia aislada de succinato-coenzima q reductasa; deficiencia aislada de succinato-ubiquinona reductasa; deficiencia aislada del complejo 2 de la cadena respiratoria mitocondrial; deficiencia aislada del complejo ii de la cadena respiratoria mitocondrial","Category_Linearization__c":"ORPHA:68367","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":"Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The symptoms can vary greatly from serious symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by genetic changes in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying genetic changes cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency genetic change carriers may be at an increased risk for certain cancers.","Curated_Disease_Description_Source__c":"GARD:0005053","GARD_Synonym__c":"isolated mitochondrial respiratory chain complex ii deficiency; isolated succinate dehydrogenase deficiency; isolated succinate-coenzyme q reductase deficiency; isolated succinate-coq reductase deficiency; isolated succinate-ubiquinone reductase deficiency; mitochondrial complex ii deficiency; mitochondrial respiratory chain complex ii deficiency; mitochondrial respiratory chain complex ii deficiency, sdha-related; mitochondrial respiratory chain complex ii deficiency, sdhaf1-related; succinate coq reductase deficiency","Name":"Mitochondrial complex II deficiency, nuclear type 1","Curated_USA_Estimate__c":"1,000","estimateUsa":"1,000"}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"United Mitochondrial Disease Foundation","Website__c":"https://www.umdf.org"},{"Account_Name__c":"MitoAction","Website__c":"https://www.mitoaction.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":"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":"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":"Neurodevelopmental disabilities","Tag_Category__c":"Specialist","curated_tag_name":"Neurodevelopmental disabilities"},{"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":"Infancy","Provided_By__c":"ORPHA:3208"},{"Age_At_Onset__c":"Neonatal","Provided_By__c":"ORPHA:3208"}],"External_Identifier_Disease__c":[{"URL__c":"https://raresource.nih.gov/diseases/filter/0005053","Source__c":"RareSource"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=124165006","Source__c":"MONDO:0100294","Xref__c":"124165006"},{"URL__c":"https://www.ebi.ac.uk/ols4/ontologies/doid/classes?obo_id=DOID%3A0060537","Source__c":"MONDO:0100294","Xref__c":"DOID:0060537"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C5700310","Source__c":"C5700310","Xref__c":"C5700310"},{"URL__c":"https://www.orpha.net/en/disease/detail/3208","Source__c":"C5700310; MONDO:0100294","Xref__c":"ORPHA:3208"},{"URL__c":"https://www.omim.org/entry/252011","Source__c":"C5700310; MONDO:0100294","Xref__c":"OMIM:252011"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=1814582","Source__c":"C5700310","Xref__c":"MEDGEN:1814582"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C565375","Source__c":"MONDO:0100294","Xref__c":"C565375"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0100294","Source__c":"GARD:0005053","Xref__c":"MONDO:0100294"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"SDHA","GHR_URL__c":"https://medlineplus.gov/genetics/gene/sdha","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"Inheritance__c":["Autosomal recessive"],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002359","HPO_Synonym__c":"Frequent falls","HPO_Name__c":"Frequent falls","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A lack of strength of the proximal muscles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003701","HPO_Synonym__c":"Muscle weakness, proximal; Proximal limb muscle weakness; Proximal limb weakness; Weakness in muscles of upper arms and upper legs","HPO_Name__c":"Proximal muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003324","HPO_Synonym__c":"Generalized weakness; Muscle weakness, diffuse; Muscle weakness, generalized","HPO_Name__c":"Generalized muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007272","HPO_Synonym__c":"Progressive mental and motor deterioration","HPO_Name__c":"Progressive psychomotor deterioration","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","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:3208","HPO_Frequency__c":"Frequent (30-79%)","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:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Any abnormality of the cardiovascular system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001626","HPO_Synonym__c":"Abnormality of the cardiovascular system; Cardiovascular abnormality","HPO_Name__c":"Abnormality of the cardiovascular system","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"An emotional state characterized by negative feelings of heightened frustration, annoyance, or feeling upset, often triggered by internal factors (e.g., fatigue, hunger, unfulfilled desires) or external factors (e.g., social or environmental challenges). Irritability may be unpredictable, and is accompanied by a lowered threshold for emotional reactivity and observable features (speech, facial expressions, or psychomotor activity).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000737","HPO_Synonym__c":"Cranky; Easily annoyed; Easily bothered; Easily upset; Grumpy; Hot-temper; Irritability; Irritable; Irritable mood; On edge; Quick-temper; Short fuse; Short tempered","HPO_Name__c":"Irritability","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"The presence of skeletal muscular atrophy (which is also known as amyotrophy).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003202","HPO_Synonym__c":"Amyotrophy; Amyotrophy involving the extremities; Muscle atrophy; Muscle atrophy, neurogenic; Muscle degeneration; Muscle hypotrophy; Muscle wasting; Muscular atrophy; Neurogenic muscle atrophy; Neurogenic muscle atrophy, especially in the lower limbs; Neurogenic muscular atrophy","HPO_Name__c":"Skeletal muscle atrophy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Inability to walk in a person who previous had the ability to walk.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002505","HPO_Synonym__c":"Loss of ability to walk","HPO_Name__c":"Loss of ambulation","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Increased susceptibility to fatigue.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003388","HPO_Name__c":"Easy fatigability","Feature_System__c":"Nervous System; Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0008872","HPO_Name__c":"Feeding difficulties in infancy","Feature_System__c":"Digestive System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001511","HPO_Synonym__c":"Fetal growth restriction; FGR; In utero growth retardation; Intrauterine growth failure; Intrauterine growth restriction; Intrauterine growth retardation, IUGR; Intrauterine retardation; IUGR; Prenatal growth deficiency; Prenatal growth failure; Prenatal growth retardation; Prenatal onset growth retardation; Prenatal-onset growth retardation; Small for gestational age infant","HPO_Name__c":"Intrauterine growth retardation","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"An abnormality of the retina characterized by pigment deposition. It is typically associated with migration and proliferation of macrophages or retinal pigment epithelial cells into the retina; melanin from these cells causes the pigmentary changes. Pigmentary retinopathy is a common final pathway of many retinal conditions and is often associated with visual loss.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000580","HPO_Synonym__c":"Pigmentary retinal deposits; Retinal pigment clumping; Retinal pigmentary clumping; Retinal pigmentary degeneration","HPO_Name__c":"Pigmentary retinopathy","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Decreased occipito-frontal (head) circumference (OFC). For the microcephaly OFC must be between -3 SD and -2 SD compared to appropriate, age matched, normal standards (i.e. -3 SD <= OFC < -2 SD).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0040196","HPO_Name__c":"Mild microcephaly","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003756","HPO_Name__c":"Skeletal myopathy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006380","HPO_Synonym__c":"Flexion contracture of knees; Flexion contractures at both knees; Flexion contractures of knees; Flexion deformity of the knee; Knee flexion contractures; Knee flexion deformity","HPO_Name__c":"Knee flexion contracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Abnormal (retrograde) movement of urine from the bladder into ureters or kidneys related to inadequacy of the valvular mechanism at the ureterovesicular junction or other causes.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000076","HPO_Synonym__c":"Ureteral reflux; Ureteric reflux; Vesico-ureteral reflux; Vesicoureteric reflux; VUR","HPO_Name__c":"Vesicoureteral reflux","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006895","HPO_Name__c":"Lower limb hypertonia","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A type of Developmental delay characterized by a delay in acquiring motor skills.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001270","HPO_Synonym__c":"Delay in development of motor milestones; Delay in motor development; Delayed development of motor milestones; Delayed early motor milestones; Delayed motor development; Delayed motor milestones; Locomotor delay; Motor developmental delay; Motor developmental milestones not achieved; Motor retardation; Retarded motor development; Slow development of motor milestones","HPO_Name__c":"Motor delay","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A kind of short stature in which different regions of the body are shortened to a comparable extent.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003508","HPO_Synonym__c":"Proportionate small stature; Short stature, proportionate","HPO_Name__c":"Proportionate short stature","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Loss of developmental skills, as manifested by loss of developmental milestones.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002376","HPO_Synonym__c":"Loss of acquired milestones; Loss of developmental milestones; Loss of milestones; Mental deterioration in childhood; Neurodevelopmental regression; Psychomotor regression; Psychomotor regression beginning in infancy; Psychomotor regression in infants; Psychomotor regression, progressive","HPO_Name__c":"Developmental regression","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000726","HPO_Synonym__c":"Dementia; Dementia, progressive; Progressive dementia","HPO_Name__c":"Dementia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Spastic weakness affecting all four limbs.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001285","HPO_Synonym__c":"Spastic quadriparesis","HPO_Name__c":"Spastic tetraparesis","Feature_System__c":"Nervous System; Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Partial loss of the ability to move the lower limbs accompanied by spasticity of the lower limbs.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002313","HPO_Name__c":"Spastic paraparesis","Feature_System__c":"Nervous System; Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000618","HPO_Synonym__c":"Blindness; Total vision loss","HPO_Name__c":"Blindness","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Enlargement or increased size of the heart left ventricle.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001712","HPO_Synonym__c":"Heart left ventricle hypertrophy; Left ventricular wall hypertrophy","HPO_Name__c":"Left ventricular hypertrophy","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003487","HPO_Synonym__c":"Extensor plantar reflexes; Extensor plantar response; Extensor plantar responses; Positive Babinski sign","HPO_Name__c":"Babinski sign","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Muscular atrophy affecting muscles in the distal portions of the extremities.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003693","HPO_Synonym__c":"Amyotrophy of distal limb muscles; Distal amyotrophy, especially of the hands and feet; Distal limb muscle atrophy; Distal muscle atrophy; Distal muscle atrophy, upper and lower limbs; Distal muscle degeneration; Distal muscle wasting; Distal muscular atrophy; Muscle atrophy, distal","HPO_Name__c":"Distal amyotrophy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A severe degree of short stature, more than -4 SD from the mean corrected for age and sex.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003510","HPO_Synonym__c":"Dwarfism; Proportionate dwarfism; Severe short stature; Short stature, extreme; Short stature, severe","HPO_Name__c":"Severe short stature","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Paralysis of the external ocular muscles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000544","HPO_Synonym__c":"Chronic progressive external ophthalmoplegia; CPEO; Ophthalmoplegia externa; Paralysis or weakness of muscles within or surrounding outer part of eye; Progressive paralysis or weakness of muscles of eye motility; Progressive paralysis or weakness of muscles of eye movement","HPO_Name__c":"External ophthalmoplegia","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001639","HPO_Synonym__c":"Cardiomyopathy, hypertrophic; Enlarged and thickened heart muscle; HCM","HPO_Name__c":"Hypertrophic cardiomyopathy","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Generalized muscular hypotonia (abnormally low muscle tone).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001290","HPO_Synonym__c":"Generalized decreased muscle tone; Generalized muscular hypotonia; Hypotonia, generalized","HPO_Name__c":"Generalized hypotonia","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A type of focal motor seizure characterized by sudden, brief (<100 ms) involuntary single or multiple contraction(s) of muscles(s) 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:0011166","HPO_Synonym__c":"Focal myoclonic seizures; Local myoclonic seizures; Localised myoclonic seizure; Localized myoclonic seizure; Partial myoclonic seizure; Partial myoclonic seizures; Segmental myoclonic seizure; Segmental myoclonic seizures","HPO_Name__c":"Focal myoclonic seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Reduction of total body weight.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001824","HPO_Synonym__c":"Loss of weight","HPO_Name__c":"Weight loss","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Increased intensity of the a reflex in the arm.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007350","HPO_Synonym__c":"Hyperreflexia in upper limbs","HPO_Name__c":"Upper limb hyperreflexia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006801","HPO_Name__c":"Hyperactive deep tendon reflexes","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Inability of the left ventricle to perform its normal physiologic function. Failure is either due to an inability to contract the left ventricle or the inability to relax completely and fill with blood during diastole.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0005162","HPO_Synonym__c":"Impaired left ventricular function; Left ventricular dysfunction; Left ventricular failure; Left ventricular impairment; Left-sided heart failure","HPO_Name__c":"Abnormal left ventricular function","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007083","HPO_Synonym__c":"Hyperreflexia in knees; Overactive knee reflex","HPO_Name__c":"Hyperactive patellar reflex","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"An impairment of the electrical continuity between the atria and ventricles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0005150","HPO_Name__c":"Abnormal atrioventricular conduction","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000639","HPO_Synonym__c":"Involuntary, rapid, rhythmic eye movements","HPO_Name__c":"Nystagmus","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Any abnormality of the eye, including location, spacing, and intraocular abnormalities.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000478","HPO_Synonym__c":"Abnormal eye; Abnormality of the eye","HPO_Name__c":"Abnormality of the eye","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001250","HPO_Synonym__c":"Epileptic seizure; Seizures","HPO_Name__c":"Seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001257","HPO_Synonym__c":"Involuntary muscle stiffness, contraction, or spasm; Muscle spasticity; Muscular spasticity","HPO_Name__c":"Spasticity","Feature_System__c":"Nervous System; Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Uncommon (<1-4%)","Feature__r":{"HPO_Description__c":"Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002421","HPO_Synonym__c":"Delay in head control; Delay in head righting; Infant head lag; Poor head control","HPO_Name__c":"Poor head control","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A delay in the acquisition of the ability to use language to communicate needs, wishes, or thoughts.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002474","HPO_Synonym__c":"Deficit in expressive language","HPO_Name__c":"Expressive language delay","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A type of cardiomyopathy characterized anatomically by deep trabeculations in the ventricular wall, which define recesses communicating with the main ventricular chamber.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0012817","HPO_Synonym__c":"Noncompaction of the ventricular myocardium; Spongiform cardiomyopathy","HPO_Name__c":"Noncompaction cardiomyopathy","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A moderate delay in the achievement of motor or mental milestones in the domains of development of a child.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011343","HPO_Synonym__c":"Global developmental delay, moderate","HPO_Name__c":"Moderate global developmental delay","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Loss of previously present motor (i.e., movement) abilities.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002333","HPO_Synonym__c":"Progressive degeneration of movement","HPO_Name__c":"Motor deterioration","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:3208","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007663","HPO_Synonym__c":"Decreased central vision; Decreased clarity of vision; Decreased visual acuity; Poor visual acuity","HPO_Name__c":"Reduced visual acuity","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics","Inborn Errors of Metabolism","Mitochondrial"],"Disease Category":["Genetics","Neurology","Inborn Errors of Metabolism","Mitochondrial"],"Specialist":["Genetics","Neurology","Neurodevelopmental disabilities","Neuromuscular medicine","Pediatrics"],"Account":["Mitochondrial"]},"synonyms":["isolated mitochondrial respiratory chain complex ii deficiency"," isolated succinate dehydrogenase deficiency"," isolated succinate-coenzyme q reductase deficiency"," isolated succinate-coq reductase deficiency"," isolated succinate-ubiquinone reductase deficiency"," mitochondrial complex ii deficiency"," mitochondrial respiratory chain complex ii deficiency"," mitochondrial respiratory chain complex ii deficiency, sdha-related"," mitochondrial respiratory chain complex ii deficiency, sdhaf1-related"," succinate coq reductase deficiency"]}