{"Name":"Pelizaeus-Merzbacher disease","DiseaseID__c":"GARD:0004265","id":4265,"encodedName":"pelizaeus-merzbacher-disease","IsDeleted":false,"Disease_Name_Full__c":"Pelizaeus-Merzbacher disease","Xref_IDs__c":"64855000; C0205711; C75487; D020371; DOID:3210; MEDGEN:61440; MONDO:0010714; OMIM:312080; ORPHA:702","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":2,"World_Estimate__c":"8,000 to 80,000","No_of_HRSA_records__c":0,"Evidence_Based_Score__c":2,"No_of_Disease_Descriptions__c":4,"Disease_Characteristics_Score__c":8,"No_of_Age_at_Onset__c":1,"Description_Source__c":"MONDO:0010714","Disease_Description__c":"Pelizaeus-Merzbacher disease (PMD) is an X-linked leukodystrophy characterized by developmental delay, nystagmus, hypotonia, spasticity, and variable intellectual deficit. It is classified into three sub-forms based on the age of onset and severity: connatal, transitional, and classic PMD (see these terms).","GARD_Name__c":"Pelizaeus-Merzbacher disease","GARD_Synonym__c":"diffuse familial brain sclerosis; hld1; hypomyelinating leukodystrophy 1; leukodystrophy, hypomyelinating, 1; leukodystrophy, sudanophilic; pelizaeus merzbacher brain sclerosis; pelizaeus-merzbacher brain sclerosis; pelizaeus-merzbacher disease, x-linked recessive; pelizeaus-merzbacher spectrum disorder; pmd; sudanophilic leukodystrophy; sudanophilic leukodystrophy, paelizeus-merzbacher type","Curated_Disease_Description_Source__c":"GARD:0004265","Curated_Disease_Description__c":"Pelizaeus-Merzbacher disease is an inherited condition involving the brain and spinal cord (central nervous system) that primarily affects males. This disease is one of a group of genetic disorders called leukodystrophies. Leukodystrophies are conditions that involve abnormalities of the nervous system's white matter, which consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. In particular, Pelizaeus-Merzbacher disease involves hypomyelination, which means that the nervous system has a reduced ability to form myelin. As a result, overall neurological function is reduced. Pelizaeus-Merzbacher disease is divided into classic and connatal (present from birth) types. Although these two types differ in severity, their features can overlap. Classic Pelizaeus-Merzbacher disease is the more common type. Within the first year of life, those affected with classic Pelizaeus-Merzbacher disease typically experience weak muscle tone (hypotonia), involuntary movements of the eyes (nystagmus), and delayed development of motor skills, such as sitting or grasping objects. Some individuals are able to walk with assistance. Despite these neurological problems, intellectual and motor skills develop throughout childhood, but development usually stops around adolescence, and these skills are slowly lost (developmental regression). As the condition worsens, nystagmus usually goes away but other movement disorders develop, including muscle stiffness (spasticity), problems with movement and balance (ataxia), head and neck tremors (titubation), involuntary tensing of the muscles (dystonia), and jerking (choreiform) movements. Connatal Pelizaeus-Merzbacher disease is the more severe of the two types. Symptoms can begin in infancy and include problems with feeding, poor weight gain and slow growth, high-pitched breathing caused by an obstructed airway (stridor), nystagmus, progressive speech difficulties (dysarthria), severe ataxia, hypotonia, and seizures. As the condition worsens, affected children develop spasticity leading to joint deformities (contractures) that restrict movement. Individuals with connatal Pelizaeus-Merzbacher disease are never able to walk, and many are not able to purposefully use their arms. They also have problems producing speech (expressive language) but can generally understand speech (receptive language).","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":"5,000","Age_at_Onset_Snippet_Text__c":"at any time in life","SourceID__c":"ORPHA:702","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Grouping","MONDO_ID__c":"MONDO:0010714","ORPHANET_ID__c":"ORPHA:702","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Enfermedad de pelizaeus-merzbacher","Spanish_Description_Source__c":"ORPHA:702","Spanish_Description__c":"La enfermedad de Pelizaeus-Merzbacher (PMD) es una leucodistrofia ligada al cromosoma X caracterizada por retraso psicomotor, nistagmo, hipotonía, espasticidad y retraso mental variable. Se clasifica en tres formas según la edad de aparición y la gravedad: connatal, transitoria, y PMD clásica.","Spanish_Disease_Name__c":"enfermedad de pelizaeus-merzbacher","Spanish_GARD_Synonym__c":null,"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 is an inherited condition involving the brain and spinal cord (central nervous system) that primarily affects males. This disease is one of a group of genetic disorders called leukodystrophies. Leukodystrophies are conditions that involve abnormalities of the nervous system's white matter, which consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. In particular, Pelizaeus-Merzbacher disease involves hypomyelination, which means that the nervous system has a reduced ability to form myelin. As a result, overall neurological function is reduced. Pelizaeus-Merzbacher disease is divided into classic and connatal (present from birth) types. Although these two types differ in severity, their features can overlap. Classic Pelizaeus-Merzbacher disease is the more common type. Within the first year of life, those affected with classic Pelizaeus-Merzbacher disease typically experience weak muscle tone (hypotonia), involuntary movements of the eyes (nystagmus), and delayed development of motor skills, such as sitting or grasping objects. Some individuals are able to walk with assistance. Despite these neurological problems, intellectual and motor skills develop throughout childhood, but development usually stops around adolescence, and these skills are slowly lost (developmental regression). As the condition worsens, nystagmus usually goes away but other movement disorders develop, including muscle stiffness (spasticity), problems with movement and balance (ataxia), head and neck tremors (titubation), involuntary tensing of the muscles (dystonia), and jerking (choreiform) movements. Connatal Pelizaeus-Merzbacher disease is the more severe of the two types. Symptoms can begin in infancy and include problems with feeding, poor weight gain and slow growth, high-pitched breathing caused by an obstructed airway (stridor), nystagmus, progressive speech difficulties (dysarthria), severe ataxia, hypotonia, and seizures. As the condition worsens, affected children develop spasticity leading to joint deformities (contractures) that restrict movement. Individuals with connatal Pelizaeus-Merzbacher disease are never able to walk, and many are not able to purposefully use their arms. They also have problems producing speech (expressive language) but can generally understand speech (receptive language).","Curated_Disease_Description_Source__c":"GARD:0004265","GARD_Synonym__c":"diffuse familial brain sclerosis; hld1; hypomyelinating leukodystrophy 1; leukodystrophy, hypomyelinating, 1; leukodystrophy, sudanophilic; pelizaeus merzbacher brain sclerosis; pelizaeus-merzbacher brain sclerosis; pelizaeus-merzbacher disease, x-linked recessive; pelizeaus-merzbacher spectrum disorder; pmd; sudanophilic leukodystrophy; sudanophilic leukodystrophy, paelizeus-merzbacher type","Name":"Pelizaeus-Merzbacher disease","Curated_USA_Estimate__c":"5,000","estimateUsa":"5,000"}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"Childhood Dementia Initiative","Website__c":"https://www.childhooddementia.org/"},{"Account_Name__c":"European Leukodystrophies Association","Website__c":"https://ela-asso.com/en/"},{"Account_Name__c":"Fundación Lautaro te Necesita","Website__c":"https://fundacionlautarotenecesita.org/"},{"Account_Name__c":"Leukodystrophy Resource & Research Organisation","Website__c":"https://www.facebook.com/LeukodystrophyRRO/"},{"Account_Name__c":"Alianza Iberoamericana de Enfermedades Raras o Poco Frecuentes","Website__c":"https://aliber.org/web/"},{"Account_Name__c":"Federación Mexicana de Enfermedades Raras (FEMEXER)","Website__c":"http://www.femexer.org/"},{"Account_Name__c":"Federación Española de Enfermedades Raras","Website__c":"https://enfermedades-raras.org/"},{"Account_Name__c":"Federación Colombiana de Enfermedades Raras","Website__c":"http://www.fecoer.org"},{"Account_Name__c":"Federación Argentina de Enfermedades Poco Frecuentes","Website__c":"https://fadepof.org.ar/"},{"Account_Name__c":"Asociación Todos Unidos Enfermedades Raras Uruguay","Website__c":"https://atueru.org.uy/"},{"Account_Name__c":"United Leukodystrophy Foundation","Website__c":"https://ulf.org/"},{"Account_Name__c":"Leukodystrophy Australia","Website__c":"https://www.leuko.org.au/"},{"Account_Name__c":"The Myelin Project","Website__c":"http://www.myelin.org"},{"Account_Name__c":"Association Européenne contre les Leucodystrophies (ELA)","Website__c":"http://www.ela-asso.com"},{"Account_Name__c":"Pelizaeus-Merzbacher Disease Foundation","Website__c":"https://www.pmdfoundation.org/"},{"Account_Name__c":"Alex The Leukodystrophy Charity","Website__c":"https://www.alextlc.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":"All ages","Provided_By__c":"ORPHA:702"}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C0205711"}],"External_Identifier_Disease__c":[{"URL__c":"https://www.ncbi.nlm.nih.gov/books/NBK1182","Source__c":"Gene Review","Xref__c":"NBK1182"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=64855000","Source__c":"C0205711; MONDO:0010714","Xref__c":"64855000"},{"URL__c":"https://www.ebi.ac.uk/ols4/ontologies/doid/classes?obo_id=DOID%3A3210","Source__c":"MONDO:0010714","Xref__c":"DOID:3210"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C020371","Source__c":"C0205711; MONDO:0010714","Xref__c":"D020371"},{"URL__c":"https://evsexplore.semantics.cancer.gov/evsexplore/concept/ncit/C75487","Source__c":"C0205711; MONDO:0010714","Xref__c":"C75487"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=61440","Source__c":"C0205711","Xref__c":"MEDGEN:61440"},{"URL__c":"https://www.omim.org/entry/312080","Source__c":"C0205711; MONDO:0010714; ORPHA:702","Xref__c":"OMIM:312080"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C0205711","Source__c":"C0205711","Xref__c":"C0205711"},{"URL__c":"https://www.orpha.net/en/disease/detail/702","Source__c":"C0205711; MONDO:0010714; ORPHA:702","Xref__c":"ORPHA:702"},{"URL__c":"https://hpo.jax.org/browse/term/HP:0003269","Source__c":"C0205711","Xref__c":"HP:0003269"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0010714","Source__c":"GARD:0004265","Xref__c":"MONDO:0010714"},{"URL__c":"https://medlineplus.gov/genetics/condition/pelizaeus-merzbacher-disease","Source__c":"GARD:0004265","Xref__c":"https://medlineplus.gov/genetics/condition/pelizaeus-merzbacher-disease"},{"URL__c":"https://static1.squarespace.com/static/5c65847bab1a625acb418894/t/66041f94e3ff9110dee18d28/1711546262312/Pelizaeus+Merzbacher+Disease+PLS+Summary+v2c.pdf"}],"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 dominant","X-linked recessive"],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An anomalous configuration of blood vessels that shunts arterial blood directly into veins without passing through the capillaries.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0100026","HPO_Name__c":"Arteriovenous malformation","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"The birth of a baby of less than 37 weeks of gestational age.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001622","HPO_Synonym__c":"Premature birth; Premature delivery; Premature delivery of affected infants; Preterm birth; Preterm delivery; Shortened gestation time","HPO_Name__c":"Premature birth","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Involuntary movements characterized by both athetosis (inability to sustain muscles in a fixed position) and chorea (widespread jerky arrhythmic movements).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001266","HPO_Synonym__c":"Choreoathetoid movements","HPO_Name__c":"Choreoathetosis","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","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:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001531","HPO_Synonym__c":"Failure to thrive in first year of life; Faltering weight in infancy; Weight faltering in infancy","HPO_Name__c":"Failure to thrive in infancy","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An abnormality of the urinary system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000079","HPO_Synonym__c":"Urinary tract abnormalities; Urinary tract abnormality; Urinary tract anomalies","HPO_Name__c":"Abnormality of the urinary system","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Head circumference below 2 standard deviations below the mean for age and sex.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000252","HPO_Synonym__c":"Abnormally small cranium; Abnormally small skull; Decreased circumference of cranium; Decreased size of cranium; Decreased size of skull; Reduced head circumference; small cranium; Small head circumference","HPO_Name__c":"Microcephaly","Feature_System__c":"Nervous System; Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Involuntary fecal soiling in adults and children who have usually already been toilet trained.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002607","HPO_Synonym__c":"Anal incontinence; Fecal incontinence; Loss of bowel control","HPO_Name__c":"Bowel incontinence","Feature_System__c":"Digestive System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","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:702","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:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"The presence of an abnormal lateral curvature of the spine.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002650","HPO_Name__c":"Scoliosis","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000505","HPO_Synonym__c":"Impaired vision; Loss of eyesight; Poor vision; Visual impairment","HPO_Name__c":"Visual impairment","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An anomaly of visually evoked potentials (VEP), which are electrical potentials, initiated by brief visual stimuli, which are recorded from the scalp overlying the visual cortex.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000649","HPO_Synonym__c":"Abnormal vision evoked potentials; Abnormal visual evoked potential; Abnormal visual evoked responses; Abnormal visual-evoked potentials; VEP abnormalities","HPO_Name__c":"Abnormality of visual evoked potentials","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Atypical behavior is an abnormality in a person's actions that can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000708","HPO_Synonym__c":"Behavioral abnormality; Behavioral changes; Behavioral disorders; Behavioral disturbances; Behavioral problems; Behavioral symptoms; Behavioral/psychiatric abnormalities; Behavioural symptoms; Behavioural/Psychiatric abnormality; Psychiatric disorders; Psychiatric disturbances","HPO_Name__c":"Atypical behavior","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","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:702","HPO_Frequency__c":"Very frequent (80-99%)","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:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Exaggerated anterior convexity of the thoracic vertebral column.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002808","HPO_Synonym__c":"Gibbus deformity; Hunched back; Hyperkyphosis; Round back","HPO_Name__c":"Kyphosis","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001249","HPO_Synonym__c":"Intellectual disability; Mental deficiency; Mental retardation; Mental retardation, nonspecific; Mental-retardation; Nonprogressive intellectual disability; Nonprogressive mental retardation","HPO_Name__c":"Intellectual disability","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","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:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A decreased magnitude of the sensory perception of sound.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000365","HPO_Synonym__c":"Deafness; Hearing defect; Hearing impairment; Hypacusis","HPO_Name__c":"Hearing impairment","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","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:702","HPO_Frequency__c":"Very frequent (80-99%)","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:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002093","HPO_Synonym__c":"Respiratory impairment","HPO_Name__c":"Respiratory insufficiency","Feature_System__c":"Respiratory system","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Joint stiffness is a perceived sensation of tightness in a joint or joints when attempting to move them after a period of inactivity. Joint stiffness typically subsides over time.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001387","HPO_Synonym__c":"Joint stiffness; Stiff joint; Stiff joints","HPO_Name__c":"Joint stiffness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Atrophy of the cortex of the cerebrum.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002120","HPO_Synonym__c":"Cerebral cortex atrophy; Cortical atrophy; Decrease in size of the outer layer of the brain due to loss of brain cells","HPO_Name__c":"Cerebral cortical atrophy","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","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:702","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:702","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0009830","HPO_Synonym__c":"Peripheral nerve damage; Peripheral neuritis","HPO_Name__c":"Peripheral neuropathy","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Severe weight loss, wasting of muscle, loss of appetite, and general debility related to a chronic disease.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0004326","HPO_Synonym__c":"Wasting syndrome","HPO_Name__c":"Cachexia","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An increased susceptibility to respiratory infections as manifested by a history of recurrent respiratory infections.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002205","HPO_Synonym__c":"Frequent respiratory infections; Multiple respiratory infections; Recurrent respiratory infections; respiratory infections, recurrent; Susceptibility to respiratory infections","HPO_Name__c":"Recurrent respiratory infections","Feature_System__c":"Respiratory system; Immune System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:702","HPO_Frequency__c":"Very frequent (80-99%)","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:702","HPO_Frequency__c":"Very frequent (80-99%)","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"}}],"tags":{"Cause":["Genetics","Leukodystrophy"],"Disease Category":["Genetics","Neurology","Leukodystrophy"],"Specialist":["Genetics","Neurology","Ophthalmology","Neuro-Ophthalmology","Neurodevelopmental disabilities","Pediatrics"],"Account":["Leukodystrophy"]},"synonyms":["diffuse familial brain sclerosis"," hld1"," hypomyelinating leukodystrophy 1"," leukodystrophy, hypomyelinating, 1"," leukodystrophy, sudanophilic"," pelizaeus merzbacher brain sclerosis"," pelizaeus-merzbacher brain sclerosis"," pelizaeus-merzbacher disease, x-linked recessive"," pelizeaus-merzbacher spectrum disorder"," pmd"," sudanophilic leukodystrophy"," sudanophilic leukodystrophy, paelizeus-merzbacher type"],"spanishId":13086,"spanishName":"enfermedad-de-pelizaeus-merzbacher"}