{"Name":"Sphingolipid activator protein 1 deficiency","DiseaseID__c":"GARD:0010674","id":10674,"encodedName":"sphingolipid-activator-protein-1-deficiency","IsDeleted":false,"Disease_Name_Full__c":"Sphingolipid activator protein 1 deficiency","Xref_IDs__c":"1003375005; 297278001; 68390005; C0268262; C562609; MEDGEN:120624; MONDO:0009590; OMIM:249900","USA_Estimate__c":null,"No_of_Specialist_Tagsa__c":2,"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":1,"Disease_Characteristics_Score__c":7,"No_of_Age_at_Onset__c":0,"Description_Source__c":"MEDGEN:C0268262","Disease_Description__c":"Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter. Sulfatide accumulation in myelin-producing cells causes progressive destruction of white matter (leukodystrophy) throughout the nervous system, including in the brain and spinal cord (the central nervous system) and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system).In people with metachromatic leukodystrophy, white matter damage causes progressive deterioration of intellectual functions and motor skills, such as the ability to walk. Affected individuals also develop loss of sensation in the extremities (peripheral neuropathy), incontinence, seizures, paralysis, an inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. While neurological problems are the primary feature of metachromatic leukodystrophy, effects of sulfatide accumulation on other organs and tissues have been reported, most often involving the gallbladder.The most common form of metachromatic leukodystrophy, affecting about 50 to 60 percent of all individuals with this disorder, is called the late infantile form. This form of the disorder usually appears in the second year of life. Affected children lose any speech they have developed, become weak, and develop problems with walking (gait disturbance). As the disorder worsens, muscle tone generally first decreases, and then increases to the point of rigidity. Individuals with the late infantile form of metachromatic leukodystrophy typically do not survive past childhood.In 20 to 30 percent of individuals with metachromatic leukodystrophy, onset occurs between the age of 4 and adolescence. In this juvenile form, the first signs of the disorder may be behavioral problems and increasing difficulty with schoolwork. Progression of the disorder is slower than in the late infantile form, and affected individuals may survive for about 20 years after diagnosis.The adult form of metachromatic leukodystrophy affects approximately 15 to 20 percent of individuals with the disorder. In this form, the first symptoms appear during the teenage years or later. Often behavioral problems such as alcoholism, drug abuse, or difficulties at school or work are the first symptoms to appear. The affected individual may experience psychiatric symptoms such as delusions or hallucinations. People with the adult form of metachromatic leukodystrophy may survive for 20 to 30 years after diagnosis. During this time there may be some periods of relative stability and other periods of more rapid decline.Metachromatic leukodystrophy gets its name from the way cells with an accumulation of sulfatides appear when viewed under a microscope. The sulfatides form granules that are described as metachromatic, which means they pick up color differently than surrounding cellular material when stained for examination.","GARD_Name__c":"Sphingolipid activator protein 1 deficiency","GARD_Synonym__c":"metachromatic leukodystrophy due to cerebroside sulfatase activator deficiency; metachromatic leukodystrophy due to deficiency of cerebroside sulfatase activator; metachromatic leukodystrophy due to sap-b deficiency; metachromatic leukodystrophy due to saposin b deficiency; sapi - sphingolipid activator protein i deficiency; saposin b deficiency","Curated_Disease_Description_Source__c":"MEDGEN:C0268262","Curated_Disease_Description__c":"The adult form of metachromatic leukodystrophy affects approximately 15 to 20 percent of individuals with the disorder. In this form, the first symptoms appear during the teenage years or later. Often behavioral problems such as alcohol use disorder, drug abuse, or difficulties at school or work are the first symptoms to appear. The affected individual may experience psychiatric symptoms such as delusions or hallucinations. People with the adult form of metachromatic leukodystrophy may survive for 20 to 30 years after diagnosis. During this time there may be some periods of relative stability and other periods of more rapid decline.  In 20 to 30 percent of individuals with metachromatic leukodystrophy, onset occurs between the age of 4 and adolescence. In this juvenile form, the first signs of the disorder may be behavioral problems and increasing difficulty with schoolwork. Progression of the disorder is slower than in the late infantile form, and affected individuals may survive for about 20 years after diagnosis.  The most common form of metachromatic leukodystrophy, affecting about 50 to 60 percent of all individuals with this disorder, is called the late infantile form. This form of the disorder usually appears in the second year of life. Affected children lose any speech they have developed, become weak, and develop problems with walking (gait disturbance). As the disorder worsens, muscle tone generally first decreases, and then increases to the point of rigidity. Individuals with the late infantile form of metachromatic leukodystrophy typically do not survive past childhood.  Metachromatic leukodystrophy gets its name from the way cells with an accumulation of sulfatides appear when viewed under a microscope. The sulfatides form granules that are described as metachromatic, which means they pick up color differently than surrounding cellular material when stained for examination.  In people with metachromatic leukodystrophy, white matter damage causes progressive deterioration of intellectual functions and motor skills, such as the ability to walk. Affected individuals also develop loss of sensation in the extremities (peripheral neuropathy), incontinence, seizures, paralysis, an inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. While neurological problems are the primary feature of metachromatic leukodystrophy, effects of sulfatide accumulation on other organs and tissues have been reported, most often involving the gallbladder.  Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter. Sulfatide accumulation in myelin-producing cells causes progressive destruction of white matter (leukodystrophy) throughout the nervous system, including in the brain and spinal cord (the central nervous system) and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system).","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":null,"Age_at_Onset_Snippet_Text__c":null,"SourceID__c":null,"Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0009590","ORPHANET_ID__c":null,"Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":null,"Spanish_Description_Source__c":null,"Spanish_Description__c":null,"Spanish_Disease_Name__c":null,"Spanish_GARD_Synonym__c":null,"Category_Linearization__c":null,"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":"The adult form of metachromatic leukodystrophy affects approximately 15 to 20 percent of individuals with the disorder. In this form, the first symptoms appear during the teenage years or later. Often behavioral problems such as alcohol use disorder, drug abuse, or difficulties at school or work are the first symptoms to appear. The affected individual may experience psychiatric symptoms such as delusions or hallucinations. People with the adult form of metachromatic leukodystrophy may survive for 20 to 30 years after diagnosis. During this time there may be some periods of relative stability and other periods of more rapid decline.  In 20 to 30 percent of individuals with metachromatic leukodystrophy, onset occurs between the age of 4 and adolescence. In this juvenile form, the first signs of the disorder may be behavioral problems and increasing difficulty with schoolwork. Progression of the disorder is slower than in the late infantile form, and affected individuals may survive for about 20 years after diagnosis.  The most common form of metachromatic leukodystrophy, affecting about 50 to 60 percent of all individuals with this disorder, is called the late infantile form. This form of the disorder usually appears in the second year of life. Affected children lose any speech they have developed, become weak, and develop problems with walking (gait disturbance). As the disorder worsens, muscle tone generally first decreases, and then increases to the point of rigidity. Individuals with the late infantile form of metachromatic leukodystrophy typically do not survive past childhood.  Metachromatic leukodystrophy gets its name from the way cells with an accumulation of sulfatides appear when viewed under a microscope. The sulfatides form granules that are described as metachromatic, which means they pick up color differently than surrounding cellular material when stained for examination.  In people with metachromatic leukodystrophy, white matter damage causes progressive deterioration of intellectual functions and motor skills, such as the ability to walk. Affected individuals also develop loss of sensation in the extremities (peripheral neuropathy), incontinence, seizures, paralysis, an inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. While neurological problems are the primary feature of metachromatic leukodystrophy, effects of sulfatide accumulation on other organs and tissues have been reported, most often involving the gallbladder.  Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter. Sulfatide accumulation in myelin-producing cells causes progressive destruction of white matter (leukodystrophy) throughout the nervous system, including in the brain and spinal cord (the central nervous system) and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system).","Curated_Disease_Description_Source__c":"MEDGEN:C0268262","GARD_Synonym__c":"metachromatic leukodystrophy due to cerebroside sulfatase activator deficiency; metachromatic leukodystrophy due to deficiency of cerebroside sulfatase activator; metachromatic leukodystrophy due to sap-b deficiency; metachromatic leukodystrophy due to saposin b deficiency; sapi - sphingolipid activator protein i deficiency; saposin b deficiency","Name":"Sphingolipid activator protein 1 deficiency","estimateUsa":""}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"Childhood Dementia Initiative","Website__c":"https://www.childhooddementia.org/"},{"Account_Name__c":"MLD Foundation","Website__c":"https://mldfoundation.org/"},{"Account_Name__c":"Alex The Leukodystrophy Charity","Website__c":"https://www.alextlc.org"},{"Account_Name__c":"Hunter's Hope Foundation","Website__c":"https://www.huntershope.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":"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":"Lysosomal","Tag_Category__c":"Account;Cause;Disease Category","category_description":"Lysosomal storage diseases are a group of genetic metabolic diseases that affect the ability of the body's cells to break down substances and remove toxins.","curated_tag_name":"Lysosomal storage diseases"},{"Tag_Name__c":"Neuromuscular medicine","Tag_Category__c":"Specialist","curated_tag_name":"Neuromuscular medicine"}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C0268262"}],"External_Identifier_Disease__c":[{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=120624","Source__c":"C0268262","Xref__c":"MEDGEN:120624"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C0268262","Source__c":"C0268262","Xref__c":"C0268262"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C562609","Source__c":"MONDO:0009590","Xref__c":"C562609"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=68390005","Source__c":"C0268262; MONDO:0009590","Xref__c":"68390005"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=1003375005","Source__c":"MONDO:0009590","Xref__c":"1003375005"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=297278001","Source__c":"C0268262; MONDO:0009590","Xref__c":"297278001"},{"URL__c":"https://www.omim.org/entry/249900","Source__c":"C0268262; MONDO:0009590","Xref__c":"OMIM:249900"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0009590","Source__c":"GARD:0010674","Xref__c":"MONDO:0009590"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"PSAP","GHR_URL__c":"https://medlineplus.gov/genetics/gene/psap","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"Inheritance__c":["Autosomal recessive"],"GARD_Disease_Feature__c":[{"Provided_By__c":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","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":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A reduction in the speed at which electrical signals propagate along the axon of a neuron.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000762","HPO_Synonym__c":"Decreased NCV; Decreased nerve conduction velocities; Delayed nerve conduction velocity; Reduced nerve conduction velocities; Slow nerve conduction velocity; Slowed nerve conduction velocities","HPO_Name__c":"Decreased nerve conduction velocity","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Procedure_NCV"}},{"Provided_By__c":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A generalized disorder of peripheral nerves.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001271","HPO_Synonym__c":"Peripheral nerve disease","HPO_Name__c":"Polyneuropathy","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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":"OMIM:249900","Feature__r":{"HPO_Description__c":"Loss of the ability to control the urinary bladder leading to involuntary urination.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000020","HPO_Synonym__c":"Bladder incontinence; Loss of bladder control","HPO_Name__c":"Urinary incontinence","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Reduced strength of muscles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001324","HPO_Synonym__c":"Muscle weakness; Muscular weakness","HPO_Name__c":"Muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"Loss of previously present mental abilities, generally in adults.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001268","HPO_Synonym__c":"Cognitive decline; Cognitive decline, progressive; Intellectual deterioration; Mental deterioration; Progressive cognitive decline","HPO_Name__c":"Mental deterioration","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A loss of myelin from the internode regions along myelinated nerve fibers of the peripheral nervous system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0011096","HPO_Synonym__c":"Demyelination","HPO_Name__c":"Peripheral demyelination","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","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":"OMIM:249900","Feature__r":{"HPO_Description__c":"A structural abnormality of the myelinated axons (white matter) located near the cerebral ventricles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002518","HPO_Synonym__c":"Abnormality of the periventricular white matter","HPO_Name__c":"Abnormal periventricular white matter morphology","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","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":"OMIM:249900","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Increased concentration of protein in the cerebrospinal fluid.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002922","HPO_Synonym__c":"Cerebrospinal fluid protein increased; Cerebrospinal fluid with increased protein; Elevated cerebrospinal fluid protein; Elevated csf protein; Hyperproteinorrhachia; Increased CSF protein; Increased protein in csf; Spinal fluid protein elevated","HPO_Name__c":"Increased CSF protein concentration","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Lab"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002066","HPO_Synonym__c":"Ataxia of gait; Ataxic gait; Inability to coordinate movements when walking","HPO_Name__c":"Gait ataxia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"Difficulty in swallowing.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002015","HPO_Synonym__c":"Difficulty swallowing; Poor swallowing; Swallowing difficulties; Swallowing difficulty","HPO_Name__c":"Dysphagia","Feature_System__c":"Nervous System; Digestive System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001347","HPO_Synonym__c":"Increased deep tendon reflexes; Increased reflexes","HPO_Name__c":"Hyperreflexia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001260","HPO_Synonym__c":"Difficulty articulating speech; Dysarthric speech","HPO_Name__c":"Dysarthria","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Description__c":"Reduction of neurologic reflexes such as the knee-jerk reaction.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001265","HPO_Synonym__c":"Decreased reflex response; Decreased reflexes","HPO_Name__c":"Hyporeflexia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","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":"OMIM:249900","Feature__r":{"HPO_Description__c":"A loss of myelin from nerve fibers in the central nervous system.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007305","HPO_Synonym__c":"Demyelination in central white matter","HPO_Name__c":"CNS demyelination","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:249900","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002371","HPO_Synonym__c":"Loss of speech","HPO_Name__c":"Loss of speech","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics","Leukodystrophy","Lysosomal"],"Disease Category":["Genetics","Leukodystrophy","Lysosomal"],"Specialist":["Genetics","Neuromuscular medicine"],"Account":["Leukodystrophy","Lysosomal"]},"synonyms":["metachromatic leukodystrophy due to cerebroside sulfatase activator deficiency"," metachromatic leukodystrophy due to deficiency of cerebroside sulfatase activator"," metachromatic leukodystrophy due to sap-b deficiency"," metachromatic leukodystrophy due to saposin b deficiency"," sapi - sphingolipid activator protein i deficiency"," saposin b deficiency"]}