{"Name":"Pelizaeus-Merzbacher disease, classic form","DiseaseID__c":"GARD:0021073","id":21073,"encodedName":"pelizaeus-merzbacher-disease-classic-form","IsDeleted":false,"Disease_Name_Full__c":"Pelizaeus-Merzbacher disease, classic form","Xref_IDs__c":"423022860; 87607002; C0751916; MEDGEN:155959; MONDO:0017222; ORPHA:280219","USA_Estimate__c":"5,000","No_of_Specialist_Tagsa__c":6,"No_of_ClinGen_records__c":0,"No_of_GeneReviews__c":0,"No_of_HHS_records__c":1,"World_Estimate__c":"8,000 to 80,000","No_of_HRSA_records__c":0,"Evidence_Based_Score__c":1,"No_of_Disease_Descriptions__c":1,"Disease_Characteristics_Score__c":8,"No_of_Age_at_Onset__c":2,"Description_Source__c":"MONDO:0017222","Disease_Description__c":"The classic form of Pelizaeus-Merzbacher disease (PMD) is the infantile form of PMD.","GARD_Name__c":"Pelizaeus-Merzbacher disease, classic form","GARD_Synonym__c":"classic pmd; type i classic pelizaeus-merzbacher disease","Curated_Disease_Description_Source__c":"MONDO:0017222","Curated_Disease_Description__c":"Pelizaeus-Merzbacher disease (PMD) is a rare, neurodegenerative disorder, and is one of a group of genetic disorders called leukodystrophies affecting the white matter of the brain and spinal cord. There are two main types of PMD: classic PMD and connatal PMD. Pelizaeus-Merzbacher disease – classic form (classic PMD) is the most common type.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":"5,000","Age_at_Onset_Snippet_Text__c":"as a Newborn and as an Infant","SourceID__c":"ORPHA:280219","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0017222","ORPHANET_ID__c":"ORPHA:280219","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Enfermedad de pelizaeus-merzbacher, forma clásica","Spanish_Description_Source__c":"ORPHA:280219","Spanish_Description__c":"La forma clásica de la enfermedad de Pelizaeus-Merzbacher (PMD) es la forma infantil de la PMD (consulte este término).","Spanish_Disease_Name__c":"enfermedad de pelizaeus-merzbacher, forma clásica","Spanish_GARD_Synonym__c":"pmd clásica","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":"Pelizaeus-Merzbacher disease (PMD) is a rare, neurodegenerative disorder, and is one of a group of genetic disorders called leukodystrophies affecting the white matter of the brain and spinal cord. There are two main types of PMD: classic PMD and connatal PMD. Pelizaeus-Merzbacher disease – classic form (classic PMD) is the most common type.","Curated_Disease_Description_Source__c":"MONDO:0017222","GARD_Synonym__c":"classic pmd; type i classic pelizaeus-merzbacher disease","Name":"Pelizaeus-Merzbacher disease, classic form","Curated_USA_Estimate__c":"5,000","estimateUsa":"5,000"}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"Pelizaeus-Merzbacher Disease Foundation","Website__c":"https://www.pmdfoundation.org/"},{"Account_Name__c":"United Leukodystrophy Foundation","Website__c":"https://ulf.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":"Ophthalmology","Tag_Category__c":"Specialist"},{"Tag_Name__c":"Leukodystrophy","Tag_Category__c":"Account;Cause;Disease Category","category_description":"Leukodystrophies are a group of genetic neurological diseases that affect the white matter of the brain and spinal cord.","curated_tag_name":"Leukodystrophies"},{"Tag_Name__c":"Neuro-Ophthalmology","Tag_Category__c":"Specialist","curated_tag_name":"Neuro-ophthalmic diseases"},{"Tag_Name__c":"Neurodevelopmental disabilities","Tag_Category__c":"Specialist","curated_tag_name":"Neurodevelopmental disabilities"},{"Tag_Name__c":"Pediatrics","Tag_Category__c":"Specialist"}],"Age_At_Onset__c":[{"Age_At_Onset__c":"Infancy","Provided_By__c":"ORPHA:280219"},{"Age_At_Onset__c":"Neonatal","Provided_By__c":"ORPHA:280219"}],"External_Identifier_Disease__c":[{"URL__c":"https://www.orpha.net/en/disease/detail/280219","Source__c":"C0751916; MONDO:0017222; ORPHA:280219","Xref__c":"ORPHA:280219"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=155959","Source__c":"C0751916","Xref__c":"MEDGEN:155959"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=87607002","Source__c":"C0751916; MONDO:0017222","Xref__c":"87607002"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C0751916","Source__c":"C0751916","Xref__c":"C0751916"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0017222","Source__c":"GARD:0021073","Xref__c":"MONDO:0017222"},{"URL__c":"https://secure.ssa.gov/apps10/poms.nsf/lnx/0423022860","Xref__c":"423022860"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"PLP1","GHR_URL__c":"https://medlineplus.gov/genetics/gene/plp1","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"Inheritance__c":["X-linked recessive"],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Athetosis involves continuous smooth movements that appear random and are not composed of recognizable sub-movements or movement fragments. In contrast to chorea, in athetosis, the same regions of the body are repeatedly involved. Athetosis may worsen with attempts at movement of posture, but athetosis can also occur at rest.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002305","HPO_Synonym__c":"Athetoid movements; Involuntary writhing movements; Involuntary writhing movements in fingers, hands, toes, and feet","HPO_Name__c":"Athetosis","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"EEG with abnormally slow frequencies.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011203","HPO_Name__c":"EEG with abnormally slow frequencies","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_EEG"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","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:280219","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:280219","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Dystonic gait disorders frequently appear bizarre, particularly because activity increases dystonic tonus and posture. The abnormal posture of the foot in dystonic gait typically involves inversion, plantar flexion and tonic extension of the big toe. In many patients complex types of walking, such as walking backwards and running are paradoxically less impaired than walking forward and may seem completely unaffected. Sensory tricks, for instance, if the affected individual rests a hand on his or her neck, may improve or even normalize dystonic gait in some patients.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0031954","HPO_Name__c":"Dystonic gait","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Reduced amount of myelin in the nervous system resulting from defective myelinogenesis in the white matter of the central nervous system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006808","HPO_Synonym__c":"Hypomyelination of the brain","HPO_Name__c":"Cerebral hypomyelination","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","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:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Functional neurological abnormalities related to dysfunction of the pyramidal tract.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007256","HPO_Synonym__c":"Corticospinal signs; Pyramidal signs; Pyramidal tract signs","HPO_Name__c":"Abnormal pyramidal sign","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An abnormality of somatosensory evoked potentials (SSEP), i.e., of the electrical signals of sensation going from the body to the brain in response to a defined stimulus. Recording electrodes are placed over the scalp, spine, and peripheral nerves proximal to the stimulation site. Clinical studies generally use electrical stimulation of peripheral nerves to elicit potentials. SSEP testing determines whether peripheral sensory nerves are able to transmit sensory information like pain, temperature, and touch to the brain. Abnormal SSEPs can result from dysfunction at the level of the peripheral nerve, plexus, spinal root, spinal cord, brain stem, thalamocortical projections, or primary somatosensory cortex.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007377","HPO_Synonym__c":"Abnormality of SSEPs","HPO_Name__c":"Abnormality of somatosensory evoked potentials","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0008936","HPO_Synonym__c":"Low muscle tone in trunk; Muscular hypotonia of the trunk; Truncal hypotonia","HPO_Name__c":"Axial hypotonia","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","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:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Areas of brighter than expected MRI signal in the white matter of the brain whereby individual patches run together.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0040330","HPO_Name__c":"Confluent hyperintensity of cerebral white matter on MRI","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Imaging_MRI"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The term gait disturbance can refer to any disruption of the ability to walk.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001288","HPO_Synonym__c":"Abnormal gait; Abnormal walk; Difficulty in walking; Gait abnormalities; Gait difficulties; Gait disturbances; Impaired gait; Walking disability","HPO_Name__c":"Gait disturbance","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0031936","HPO_Synonym__c":"Delayed walking","HPO_Name__c":"Delayed ability to walk","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","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:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001332","HPO_Synonym__c":"Dystonic movements","HPO_Name__c":"Dystonia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","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:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001252","HPO_Synonym__c":"Low muscle tone; Low or weak muscle tone; Muscle hypotonia; Muscular hypotonia","HPO_Name__c":"Hypotonia","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001256","HPO_Synonym__c":"Intellectual disability, mild; Mental retardation, borderline-mild; Mild and nonprogressive mental retardation; Mild mental retardation","HPO_Name__c":"Mild intellectual disability","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A neurological condition related to lesions of the basal ganglia leading to typical abnormalities including akinesia (inability to initiate changes in activity and perform volitional movements rapidly and easily), muscular rigidity (continuous contraction of muscles with constant resistance to passive movement), chorea (widespread arrhythmic movements of a forcible, rapid, jerky, and restless nature), athetosis (inability to sustain the muscles of the fingers, toes, or other group of muscles in a fixed position), and akathisia (inability to remain motionless).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002071","HPO_Synonym__c":"Extrapyramidal dysfunction; Extrapyramidal signs; Extrapyramidal symptoms; Extrapyramidal syndrome; Extrapyramidal tract signs","HPO_Name__c":"Abnormality of extrapyramidal motor function","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An unintentional, oscillating to-and-fro muscle movement affecting head movement.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002346","HPO_Synonym__c":"Head tremor","HPO_Name__c":"Head tremor","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","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:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An abnormality in the sound (volume) or cadence (rate) of speech.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002167","HPO_Synonym__c":"Abnormal speech; Abnormal vocalization; Abnormality of speech or vocalization","HPO_Name__c":"Abnormal speech pattern","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Nodding movement of the head or body.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0030187","HPO_Name__c":"Titubation","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002310","HPO_Synonym__c":"Orofacial dyskinesias","HPO_Name__c":"Orofacial dyskinesia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A degree of language development that is significantly below the norm for a child of a specified age.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000750","HPO_Synonym__c":"Deficiency of speech development; Delayed language development; Delayed speech; Delayed speech acquisition; Delayed speech and language development; Delayed speech development; Impaired speech and language development; Impaired speech development; Language delay; Language delayed; Language development deficit; Late-onset speech development; Poor language development; Speech and language delay; Speech and language difficulties; Speech delay","HPO_Name__c":"Delayed speech and language development","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:280219","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A failure to achieve the ability to sit at an appropriate developmental stage. Most children sit with support at 6 months of age and sit steadily without support at 9 months of age.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0025336","HPO_Name__c":"Delayed ability to sit","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics","Leukodystrophy"],"Disease Category":["Genetics","Neurology","Leukodystrophy"],"Specialist":["Genetics","Neurology","Ophthalmology","Neuro-Ophthalmology","Neurodevelopmental disabilities","Pediatrics"],"Account":["Leukodystrophy"]},"synonyms":["classic pmd"," type i classic pelizaeus-merzbacher disease"]}