{"Name":"Hemimegalencephaly","DiseaseID__c":"GARD:0002637","id":2637,"encodedName":"hemimegalencephaly","IsDeleted":false,"Disease_Name_Full__c":"Hemimegalencephaly","Xref_IDs__c":"253170008; C0431391; C177779; D065705; HP:0007206; MEDGEN:140910; MONDO:0020492; ORPHA:99802","USA_Estimate__c":null,"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":null,"No_of_HRSA_records__c":0,"Evidence_Based_Score__c":0,"No_of_Disease_Descriptions__c":3,"Disease_Characteristics_Score__c":7,"No_of_Age_at_Onset__c":1,"Description_Source__c":"MONDO:0020492","Disease_Description__c":"Hemimegalencephaly is a rare cerebral malformation characterized by overgrowth of all or part of a cerebral hemisphere, often with ipsilateral severe cortical dysplasia or dysgenesis, white matter hypertrophy and dilated lateral ventricle, presenting in early infancy with progressive hemiparesis, severe psychomotor retardation and intractable seizures. Hemimegalencephaly may be an isolated finding or associated with other syndromes such as angioosteohypertrophic syndrome, epidermal nevus syndrome and Ito hypomelanosis (see these terms). Management includes seizure control by antiepileptic medications and early hemispherectomy.","GARD_Name__c":"Hemimegalencephaly","GARD_Synonym__c":"unilateral megalencephaly","Curated_Disease_Description_Source__c":"GARD:0002637","Curated_Disease_Description__c":"Hemimegalencephaly is a rare malformation involving one side of the brain. It may occur alone or in association with other syndromes such as Proteus syndrome, tuberous sclerosis, linear sebaceous nevus syndrome, neurofibromatosis, Sturge-Weber syndrome, or Klippel-Trenaunay syndrome. Children with this disorder may have a large, asymmetrical head accompanied by seizures, partial paralysis, and impaired cognitive development. The cause of Hemimegalencephaly is not fully understood, but involves a disturbance of cells early in development and likely involves genes involved in patterning and symmetry.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":null,"Age_at_Onset_Snippet_Text__c":"as an Infant","SourceID__c":"ORPHA:99802","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0020492","ORPHANET_ID__c":"ORPHA:99802","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Hemimegalencefalia","Spanish_Description_Source__c":"ORPHA:99802","Spanish_Description__c":"Es una malformación cerebral poco frecuente caracterizada por un crecimiento excesivo de la totalidad o parte de un hemisferio cerebral, a menudo con displasia o disgenesia cortical grave ipsilateral, hipertrofia de la sustancia blanca y dilatación del ventrículo lateral, que se manifiesta en la primera infancia como hemiparesia progresiva, retraso psicomotor grave y crisis epilépticas intratables. La hemimegalencefalia puede ser un hallazgo aislado o asociado a otros síndromes como el síndrome angioosteohipertrófico, el síndrome del nevus epidérmico y la hipomelanosis de Ito. El manejo incluye el control de las crisis con medicamentos anticonvulsivantes y hemisferectomía temprana.","Spanish_Disease_Name__c":"hemimegalencefalia","Spanish_GARD_Synonym__c":"megalencefalia unilateral","Category_Linearization__c":"ORPHA:93890","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":"Hemimegalencephaly is a rare malformation involving one side of the brain. It may occur alone or in association with other syndromes such as Proteus syndrome, tuberous sclerosis, linear sebaceous nevus syndrome, neurofibromatosis, Sturge-Weber syndrome, or Klippel-Trenaunay syndrome. Children with this disorder may have a large, asymmetrical head accompanied by seizures, partial paralysis, and impaired cognitive development. The cause of Hemimegalencephaly is not fully understood, but involves a disturbance of cells early in development and likely involves genes involved in patterning and symmetry.","Curated_Disease_Description_Source__c":"GARD:0002637","GARD_Synonym__c":"unilateral megalencephaly","Name":"Hemimegalencephaly","estimateUsa":""}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"The Hemispherectomy Foundation","Website__c":"https://hemifoundation.homestead.com/welcome.html"},{"Account_Name__c":"Klippel-Trenaunay Support Group","Website__c":"https://k-t.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":"Endocrine","Tag_Category__c":"Disease Category;Specialist","category_description":"Endocrine diseases affect hormone production or how the body responds to a specific hormone(s).","curated_tag_name":"Endocrine diseases"},{"Tag_Name__c":"Congenital Abnormality","Tag_Category__c":"Disease Category","category_description":"Birth defects are structural changes present at birth that can affect almost any part of the body, including how the body looks, works, or both.","curated_tag_name":"Birth defects"},{"Tag_Name__c":"Epilepsy","Tag_Category__c":"Account;Specialist","curated_tag_name":"Epilepsy"},{"Tag_Name__c":"Pediatrics","Tag_Category__c":"Specialist"}],"Age_At_Onset__c":[{"Age_At_Onset__c":"Infancy","Provided_By__c":"ORPHA:99802"}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C0431391"}],"External_Identifier_Disease__c":[{"URL__c":"https://raresource.nih.gov/diseases/filter/0002637","Source__c":"RareSource"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=253170008","Source__c":"C0431391; MONDO:0020492","Xref__c":"253170008"},{"URL__c":"https://www.orpha.net/en/disease/detail/99802","Source__c":"C0431391; MONDO:0020492; ORPHA:99802","Xref__c":"ORPHA:99802"},{"URL__c":"https://evsexplore.semantics.cancer.gov/evsexplore/concept/ncit/C177779","Source__c":"C0431391; MONDO:0020492","Xref__c":"C177779"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C065705","Source__c":"C0431391; MONDO:0020492","Xref__c":"D065705"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C0431391","Source__c":"C0431391","Xref__c":"C0431391"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=140910","Source__c":"C0431391","Xref__c":"MEDGEN:140910"},{"URL__c":"https://hpo.jax.org/browse/term/HP:0007206","Source__c":"C0431391","Xref__c":"HP:0007206"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0020492","Source__c":"GARD:0002637","Xref__c":"MONDO:0020492"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"PIK3CA","GHR_URL__c":"https://medlineplus.gov/genetics/gene/pik3ca","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true},{"GeneSymbol__c":"AKT3","GHR_URL__c":"https://medlineplus.gov/genetics/gene/akt3","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true},{"GeneSymbol__c":"MTOR","GHR_URL__c":"https://medlineplus.gov/genetics/gene/mtor","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","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:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0004302","HPO_Synonym__c":"Functional motor problems","HPO_Name__c":"Functional motor deficit","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"EEG with focal sharp transient waves of a duration less than 80 msec.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011193","HPO_Name__c":"EEG with focal spikes","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Very frequent (80-99%)","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:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Reduced ability to control the movement of the eye associated with damage to the third cranial nerve (the oculomotor nerve).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0012246","HPO_Name__c":"Oculomotor nerve palsy","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A type of malformation of cortical development that primarily affects areas of neocortex. It can be identified on conventional magnetic resonance imaging as focal cortical thickening, abnormal gyration, and blurring between gray and white matter, often associated with clusters of heterotopic neurons.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0032046","HPO_Name__c":"Focal cortical dysplasia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An abnormality of the skull, the bony framework of the head which is comprised of the neurocranium (with eight cranial bones) and the viscerocranium (facial skeleton) that comprises fourteen facial bones with the mandible as its largest bone.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000929","HPO_Synonym__c":"Abnormality of the skull","HPO_Name__c":"Abnormal skull morphology","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001263","HPO_Synonym__c":"Delayed cognitive development; Delayed development; Delayed developmental milestones; Delayed intellectual development; Delayed milestones; Delayed psychomotor development; Developmental delay; Developmental delay in early childhood; Developmental delay, global; Developmental retardation; GDD; Lack of psychomotor development; Motor and developmental delay; Motormental retardation; Psychomotor delay; Psychomotor development deficiency; Psychomotor development failure; Psychomotor developmental delay; Retarded development; Retarded mental development; Retarded psychomotor development","HPO_Name__c":"Global developmental delay","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001269","HPO_Synonym__c":"Weakness of one side of body","HPO_Name__c":"Hemiparesis","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A structural anomaly of a neuron. Neurons are electrically excitable cells that transmit signals throughout the body. Neurons employ both electrical and chemical components in the transmission of information. Neurons are connected to other neurons at synapses and connected to effector organs or cells at neuroeffector junctions.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0012757","HPO_Synonym__c":"Abnormal neuron shape; Abnormal neuronal morphology","HPO_Name__c":"Abnormal neuron morphology","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"EEG with focal sharp transient waves of a duration between 80 and 200 msec followed by a slow wave.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011195","HPO_Name__c":"EEG with focal sharp slow waves","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Heterotopia or neuronal heterotopia are macroscopic clusters of misplaced neurons (gray matter), most often situated along the ventricular walls or within the subcortical white matter.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002282","HPO_Synonym__c":"Gray matter heterotopias; Heterotopia; Heterotopias; Neuronal heterotopia","HPO_Name__c":"Gray matter heterotopia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Severe intellectual disability (ID) is defined as a type of ID characterized by severely sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 20-34.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0010864","HPO_Synonym__c":"Early and severe mental retardation; Intellectual disability, severe; Mental retardation, severe; Severe mental retardation","HPO_Name__c":"Severe intellectual disability","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Polymicrogyria is a congenital malformation of the cerebral cortex characterized by abnormal cortical layering (lamination) and an excessive number of small gyri (folds).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002126","HPO_Synonym__c":"More grooves in brain","HPO_Name__c":"Polymicrogyria","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Pachygyria is a malformation of cortical development with abnormally wide gyri with sulci 1,5-3 cm apart and abnormally thick cortex measuring more than 5 mm (radiological definition). See also neuropathological definitions for 2-, 3-, and 4-layered lissencephaly.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001302","HPO_Synonym__c":"Cerebral pachygyria; Fewer and broader ridges in brain; Macrogyria","HPO_Name__c":"Pachygyria","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A type of focal-onset seizure characterized by a motor sign as its initial semiological manifestation.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011153","HPO_Synonym__c":"Focal motor seizures; Localized motor seizure; Localized motor seizures; Partial motor seizure; Partial motor seizures; Segmental motor seizure","HPO_Name__c":"Focal motor seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Interictal refers to a period of time between epileptic seizures. Electroencephalographic (EEG) patterns are important in the differential diagnosis of epilepsy, and the EEG is almost always abnormal during a seizure. Some persons with seizures may show EEG abnormalities between seizures, while others do not. In some cases, multiple interictal EEGs must be recorded before an abnormality is observed. In most cases the electrographic pattern of seizure onset is completely different from the activity recorded during interictal discharge.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0025373","HPO_Name__c":"Interictal EEG abnormality","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The burst suppression pattern in electroencephalography refers to a characteristic periodic pattern of low voltage (<10 microvolts) suppressed background and a relatively shorter pattern of higher amplitude slow, sharp, and spiking complexes.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0010851","HPO_Name__c":"EEG with burst suppression","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An increase in size of the ventricular system of the brain.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002119","HPO_Synonym__c":"Cerebral ventricular dilatation; Dilated cerebral ventricle; Dilated cerebral ventricles; Dilated ventricles; Enlarged cerebral ventricles; Enlarged ventricles; Enlarged ventricular system; Large cerebral ventricles and cisternae; Ventricular dilatation","HPO_Name__c":"Ventriculomegaly","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001336","HPO_Synonym__c":"Myoclonic jerks","HPO_Name__c":"Myoclonus","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Gliosis is the focal proliferation of glial cells in the central nervous system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002171","HPO_Synonym__c":"Cerebral gliosis; Excess astrocytes in brain","HPO_Name__c":"Gliosis","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006824","HPO_Synonym__c":"Cranial nerve palsies; Cranial nerve palsy; Cranial nerve paresis","HPO_Name__c":"Cranial nerve paralysis","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Atonic seizure is a type of motor seizure characterized by a sudden loss or diminution of muscle tone without apparent preceding myoclonic or tonic event lasting about 1 to 2 seconds, involving head, trunk, jaw, or limb musculature.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0010819","HPO_Synonym__c":"Astatic seizure; Astatic seizures; Atonic seizures; Drop attacks; Drop seizures; Hypotonic seizure","HPO_Name__c":"Atonic seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Status epilepticus is a type of prolonged seizure resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures (after time point t1). It is a condition that can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002133","HPO_Synonym__c":"Prolonged seizure; Repeated seizure without recovery; Repeated seizures without recovery between them","HPO_Name__c":"Status epilepticus","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A type of focal motor seizure characterized by sustained increase in muscle contraction, lasting a few seconds to minutes.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011167","HPO_Synonym__c":"Focal tonic seizures; Local tonic seizures; Localised tonic seizure; Localized tonic seizure; Partial tonic seizure; Partial tonic seizures; Segmental tonic seizure","HPO_Name__c":"Focal tonic seizure","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The presence of complexes of repetitive spikes and waves in EEG.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002392","HPO_Synonym__c":"EEG: spike and multispike waves, 3-4 hz","HPO_Name__c":"EEG with polyspike wave complexes","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Enlargement of all or parts of one cerebral hemisphere.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007206","HPO_Name__c":"Hemimegalencephaly","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A brighter than expected signal on magnetic resonance imaging emanating from the cerebral white matter.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0030890","HPO_Synonym__c":"White matter hyperintensity","HPO_Name__c":"Hyperintensity of cerebral white matter on MRI","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Imaging_MRI"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Partial or complete loss of vision in one half of the visual field of one or both eyes.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0012377","HPO_Synonym__c":"Hemianopsia","HPO_Name__c":"Hemianopia","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Asymmetry of the bones of the skull.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000267","HPO_Synonym__c":"Asymmetry of cranium; Cranial vault asymmetry","HPO_Name__c":"Cranial asymmetry","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000256","HPO_Synonym__c":"Increased size of cranium; Increased size of skull; Large head; Large head circumference; Macrocephalus; Macrocrania; Megacephaly","HPO_Name__c":"Macrocephaly","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Hypsarrhythmia occurring in one hemisphere.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011215","HPO_Name__c":"Hemihypsarrhythmia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:99802","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur: Grimacing, head nodding, or subtle eye movements. Epileptic spasms frequently occur in clusters. Infantile spasms are the best known form, but spasms can occur at all ages","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011097","HPO_Synonym__c":"Epileptic spasms; Salaam convulsion; Salaam convulsions; Salaam seizure; Salaam seizures","HPO_Name__c":"Epileptic spasm","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics"],"Disease Category":["Genetics","Neurology","Endocrine","Congenital Abnormality"],"Specialist":["Genetics","Neurology","Endocrine","Epilepsy","Pediatrics"],"Account":["Epilepsy"]},"synonyms":["unilateral megalencephaly"]}