{"Name":"Infantile-onset X-linked spinal muscular atrophy","DiseaseID__c":"GARD:0008521","id":8521,"encodedName":"infantile-onset-x-linked-spinal-muscular-atrophy","IsDeleted":false,"Disease_Name_Full__c":"Infantile-onset X-linked spinal muscular atrophy","Xref_IDs__c":"719836007; C1844934; C535380; DOID:0111827; MEDGEN:337123; MONDO:0010532; OMIM:301830; ORPHA:1145","USA_Estimate__c":"1,000","No_of_Specialist_Tagsa__c":5,"No_of_ClinGen_records__c":0,"No_of_GeneReviews__c":0,"No_of_HHS_records__c":1,"World_Estimate__c":"1 to 8,000","No_of_HRSA_records__c":0,"Evidence_Based_Score__c":1,"No_of_Disease_Descriptions__c":5,"Disease_Characteristics_Score__c":7,"No_of_Age_at_Onset__c":1,"Description_Source__c":"MONDO:0010532","Disease_Description__c":"A rare form of spinal muscular atrophy characterized by the neonatal onset of severe hypotonia, areflexia, profound weakness, multiple congenital contractures, facial dysmorphic features (myopathic face with open, tent-shaped mouth), cryptorchidism, and mild skeletal abnormalities (i.e. kyphosis, scoliosis), that is often preceded by polyhydramnios and reduced fetal movements <i>in utero</i> and followed by bone fractures shortly after birth. Muscle weakness is progressive and chest muscle involvement eventually leads to ventilatory insufficiency and respiratory failure.","GARD_Name__c":"Infantile-onset X-linked spinal muscular atrophy","GARD_Synonym__c":"amc, distal, x-linked; arthrogryposis, x-linked, type i; smax2; spinal muscular atrophy with arthrogryposis; spinal muscular atrophy, x-linked 2; spinal muscular atrophy, x-linked 2, infantile, x-linked recessive; spinal muscular atrophy, x-linked infantile; spinal muscular atrophy, x-linked lethal infantile; spinal muscular atrophy, x-linked type 2; x-linked distal arthrogryposis multiplex congenita; x-linked spinal muscular atrophy type 2","Curated_Disease_Description_Source__c":"MONDO:0010532","Curated_Disease_Description__c":"X-linked infantile spinal muscular atrophy is a condition that affects only boys and is characterized by severe muscle weakness and absent reflexes (areflexia). Affected children often have multiple joint deformities (contractures) from birth that cause joint stiffness (arthrogryposis) and impair movement. In severe cases, affected infants are born with broken bones. The muscle weakness worsens over time; affected children reach some early motor developmental milestones, such as sitting unassisted, but these skills are often lost (developmental regression). Additional features of X-linked infantile spinal muscular atrophy include an unusually small chin (micrognathia), abnormal curvature of the spine (scoliosis or kyphosis), and undescended testes (cryptorchidism). Weakness of the chest muscles used for breathing often leads to life-threatening breathing problems. Children with X-linked infantile spinal muscular atrophy usually do not survive past early childhood due to respiratory failure, although, in rare cases, affected individuals can survive into adolescence.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":"1,000","Age_at_Onset_Snippet_Text__c":"as a Newborn","SourceID__c":"ORPHA:1145","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0010532","ORPHANET_ID__c":"ORPHA:1145","Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":"Atrofia muscular espinal de inicio en el lactante ligada al cromosoma x","Spanish_Description_Source__c":"ORPHA:1145","Spanish_Description__c":"Es una forma poco frecuente de atrofia muscular espinal caracterizada por la aparición neonatal de hipotonía grave, arreflexia, debilidad profunda, contracturas congénitas múltiples, rasgos faciales dismórficos (cara miopática con boca abierta ''en carpa''), criptorquidia y anomalías esqueléticas leves (cifosis, escoliosis), con frecuencia es precedida por polihidramnios y movimientos fetales reducidos in útero>/i> seguidos de fracturas óseas poco después del nacimiento. La debilidad muscular es progresiva y la afectación de los músculos torácicos conduce eventualmente a insuficiencia ventilatoria y respiratoria.","Spanish_Disease_Name__c":"atrofia muscular espinal de inicio en el lactante ligada al cromosoma x","Spanish_GARD_Synonym__c":"artrogriposis con atrofia muscular espinal; artrogriposis distal múltiple congénita ligada al cromosoma x; atrofia muscular espinal asociada a smax2; atrofia muscular espinal ligada al cromosoma x tipo 2; smax2","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":"X-linked infantile spinal muscular atrophy is a condition that affects only boys and is characterized by severe muscle weakness and absent reflexes (areflexia). Affected children often have multiple joint deformities (contractures) from birth that cause joint stiffness (arthrogryposis) and impair movement. In severe cases, affected infants are born with broken bones. The muscle weakness worsens over time; affected children reach some early motor developmental milestones, such as sitting unassisted, but these skills are often lost (developmental regression). Additional features of X-linked infantile spinal muscular atrophy include an unusually small chin (micrognathia), abnormal curvature of the spine (scoliosis or kyphosis), and undescended testes (cryptorchidism). Weakness of the chest muscles used for breathing often leads to life-threatening breathing problems. Children with X-linked infantile spinal muscular atrophy usually do not survive past early childhood due to respiratory failure, although, in rare cases, affected individuals can survive into adolescence.","Curated_Disease_Description_Source__c":"MONDO:0010532","GARD_Synonym__c":"amc, distal, x-linked; arthrogryposis, x-linked, type i; smax2; spinal muscular atrophy with arthrogryposis; spinal muscular atrophy, x-linked 2; spinal muscular atrophy, x-linked 2, infantile, x-linked recessive; spinal muscular atrophy, x-linked infantile; spinal muscular atrophy, x-linked lethal infantile; spinal muscular atrophy, x-linked type 2; x-linked distal arthrogryposis multiplex congenita; x-linked spinal muscular atrophy type 2","Name":"Infantile-onset X-linked spinal muscular atrophy","Curated_USA_Estimate__c":"1,000","estimateUsa":"1,000"}],"Organization_Supported_Diseases__c":[{"Account_Name__c":"Muscular Dystrophy Canada","Website__c":"https://muscle.ca/"}],"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":"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":"Orthopedics","Tag_Category__c":"Specialist"},{"Tag_Name__c":"Peripheral Neuropathy","Tag_Category__c":"Account","curated_tag_name":"Peripheral neuropathy"},{"Tag_Name__c":"Congenital limb malformation","Tag_Category__c":"Account","curated_tag_name":"Limb anomalies"},{"Tag_Name__c":"Neuromuscular medicine","Tag_Category__c":"Specialist","curated_tag_name":"Neuromuscular medicine"},{"Tag_Name__c":"Pediatrics","Tag_Category__c":"Specialist"}],"Age_At_Onset__c":[{"Age_At_Onset__c":"Neonatal","Provided_By__c":"ORPHA:1145"}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C1844934"}],"External_Identifier_Disease__c":[{"URL__c":"https://raresource.nih.gov/diseases/filter/0008521","Source__c":"RareSource"},{"URL__c":"https://www.ncbi.nlm.nih.gov/books/NBK2594","Source__c":"Gene Review","Xref__c":"NBK2594"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=337123","Source__c":"C1844934","Xref__c":"MEDGEN:337123"},{"URL__c":"https://www.orpha.net/en/disease/detail/1145","Source__c":"C1844934; MONDO:0010532; ORPHA:1145","Xref__c":"ORPHA:1145"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C535380","Source__c":"MONDO:0010532","Xref__c":"C535380"},{"URL__c":"https://browser.ihtsdotools.org/?perspective=full&conceptId1=719836007","Source__c":"C1844934; MONDO:0010532","Xref__c":"719836007"},{"URL__c":"https://www.omim.org/entry/301830","Source__c":"C1844934; MONDO:0010532; ORPHA:1145","Xref__c":"OMIM:301830"},{"URL__c":"https://www.ebi.ac.uk/ols4/ontologies/doid/classes?obo_id=DOID%3A0111827","Source__c":"MONDO:0010532","Xref__c":"DOID:0111827"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C1844934","Source__c":"C1844934","Xref__c":"C1844934"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0010532","Source__c":"GARD:0008521","Xref__c":"MONDO:0010532"},{"URL__c":"https://medlineplus.gov/genetics/condition/x-linked-infantile-spinal-muscular-atrophy","Source__c":"GARD:0008521","Xref__c":"https://medlineplus.gov/genetics/condition/x-linked-infantile-spinal-muscular-atrophy"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"UBA1","GHR_URL__c":"https://medlineplus.gov/genetics/gene/uba1","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"Inheritance__c":["X-linked recessive"],"GARD_Disease_Feature__c":[{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Any abnormality of the skeletal muscle cell. Muscle fibers are subdivided into two types. Type I fibers are fatigue-resistant and rich in oxidative enzymes (they stain light with the myosin ATPase reaction), and type II fibers are fast-contracting, fatigue-prone, and rich in glycolytic enzymes (these fibers stain darkly). Normal muscle tissue has a random distribution of type I and type II fibers.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0004303","HPO_Synonym__c":"Abnormal skeletal muscle fiber morphology; Abnormality of muscle fibers","HPO_Name__c":"Abnormal muscle fiber morphology","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A partial or complete breakage of the continuity of a bone.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0020110","HPO_Name__c":"Bone fracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Reduced rib length.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000773","HPO_Synonym__c":"Hypoplastic ribs; Rib hypoplasia; Short ribs","HPO_Name__c":"Short ribs","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006466","HPO_Name__c":"Ankle flexion contracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Testis in inguinal canal. That is, absence of one or both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000028","HPO_Synonym__c":"Cryptorchism; Undescended testes; Undescended testis","HPO_Name__c":"Cryptorchidism","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000218","HPO_Synonym__c":"Elevated palate; High arched palate; High palate; High, arched palate; High-arched palate; Increased palatal height; Palate high-arched; Palate, high-arched","HPO_Name__c":"High palate","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0008180","HPO_Synonym__c":"Mildly elevated CPK; Mildly elevated creatine phosphokinase; Mildly elevated serum CK; Mildly elevated serum CPK; Mildly elevated serum phospho-CK; Mildly increased creatine kinase; Mildly increased serum creatine kinase; Moderately elevated serum CK; Moderately elevated serum CPK; Moderately increased serum creatine kinase","HPO_Name__c":"Mildly elevated creatine kinase","HPO_Feature_Type__c":"Lab"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A defect in the motor ability that enables speech.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002425","HPO_Synonym__c":"Loss of articulate speech","HPO_Name__c":"Anarthria","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","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":"ORPHA:1145","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:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A lack of strength of the proximal muscles.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003701","HPO_Synonym__c":"Muscle weakness, proximal; Proximal limb muscle weakness; Proximal limb weakness; Weakness in muscles of upper arms and upper legs","HPO_Name__c":"Proximal muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Multiple congenital contractures in different body areas.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002804","HPO_Synonym__c":"Arthrogryposis; Arthrogryposis multiplex; Arthrogryposis, congenital; Multiple congenital contractures","HPO_Name__c":"Arthrogryposis multiplex congenita","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"An elbow contracture that limits the ability of the elbow joint to be extended (straightened), meaning that the elbow is fixed in an flexed (bent) position.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002987","HPO_Synonym__c":"Elbow flexion contractures; Elbow flexion deformity; Fixed flexion at the elbow joint","HPO_Name__c":"Elbow flexion contracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007178","HPO_Synonym__c":"Peripheral motor neuropathy","HPO_Name__c":"Motor polyneuropathy","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0030319","HPO_Synonym__c":"Decreased facial muscle strength; Decreased strength of facial muscles; Face weakness; Facial muscle weakness; Facial weakness; Myasthenia of facial muscles; Reduced facial muscle strength; Weakness of face; Weakness of facial musculature","HPO_Name__c":"Weakness of facial musculature","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Lack of full passive range of motion (restrictions in flexion, extension, or other movements) of the hip joint resulting from structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules and/or skin.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003273","HPO_Synonym__c":"Flexion contracture of hips; Flexion contractures of hips; Hip contractures; Hip flexion contractures","HPO_Name__c":"Hip contracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"The presence of characteristic findings of denervation on electromyography (fibrillations, positive sharp waves, and giant motor unit potentials).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003445","HPO_Synonym__c":"EMG: neurogenic abnormalities; EMG: neurogenic changes; EMG: neurogenic findings","HPO_Name__c":"EMG: neuropathic changes","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Procedure_EMG"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Reduced strength of the musculature of the distal extremities.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002460","HPO_Synonym__c":"Distal limb muscle weakness; Distal limb weakness; Distal muscular weakness; Distal paresis; Muscle weakness, distal; Muscle weakness, distal limbs, due to neuronopathy; Weakness of distal muscles; Weakness of outermost muscles","HPO_Name__c":"Distal muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Wide, concave rib end.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0000887","HPO_Synonym__c":"Cupped ribs; Rib cupping","HPO_Name__c":"Cupped ribs","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Absence of neurologic reflexes such as the knee-jerk reaction.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001284","HPO_Synonym__c":"Absent deep tendon reflexes; Absent tendon reflexes; Deep tendon reflexes absent; Loss of deep tendon reflexes; Lost deep tendon reflexes","HPO_Name__c":"Areflexia","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Generalized muscular hypotonia (abnormally low muscle tone).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001290","HPO_Synonym__c":"Generalized decreased muscle tone; Generalized muscular hypotonia; Hypotonia, generalized","HPO_Name__c":"Generalized hypotonia","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Muscular weakness and atrophy related to loss of the motor neurons of the spinal cord and brainstem.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0007269","HPO_Synonym__c":"Spinal muscle degeneration; Spinal muscle wasting","HPO_Name__c":"Spinal muscular atrophy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Uncommon (<1-4%)","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:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"A facial appearance characteristic of a fetus or neonate due to oligohydramnios experienced in the womb, comprising ocular hypertelorism, low-set ears, receding chin, and flattening of the nose.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002009","HPO_Name__c":"Potter facies","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Floppiness/hypotonia is defined as reduced resistance to passive movement of joints. Physical examination of floppy/hypotonic infants shows head lag, lack of shoulder and elbow muscle contraction on traction response, inability to tighten the shoulder girdle muscles (or slipping through) when held under the axillae, scarf sign (when the arm is pulled to the opposite side, the arm wraps around the neck with the elbow crossing midline), hyperdorsiflexion of the feet, easy apposition of the thumb against the forearm, feet touching the cheek with ease and without discomfort, frog leg position, and inverted U sign on ventral suspension (head, arms, and legs hanging down without elbow or knee flexion and the trunk rounded in a dome shape).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0008947","HPO_Synonym__c":"Decreased muscle tone in infant; Hypotonia early; Hypotonia in infancy; Hypotonia, early; Infantile hypotonia; Infantile muscular hypotonia","HPO_Name__c":"Floppy infant","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"The presence of skeletal muscular atrophy (which is also known as amyotrophy).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003202","HPO_Synonym__c":"Amyotrophy; Amyotrophy involving the extremities; Muscle atrophy; Muscle atrophy, neurogenic; Muscle degeneration; Muscle hypotrophy; Muscle wasting; Muscular atrophy; Neurogenic muscle atrophy; Neurogenic muscle atrophy, especially in the lower limbs; Neurogenic muscular atrophy","HPO_Name__c":"Skeletal muscle atrophy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Any anomaly of the anterior horn cell.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006802","HPO_Synonym__c":"Abnormality of the anterior horn cells; Anomaly of the anterior horn cells; Anterior horn cell disease","HPO_Name__c":"Abnormal anterior horn cell morphology","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002398","HPO_Synonym__c":"Anterior horn cell loss; Degeneration of alpha-motor neurons in anterior horn cells of the spinal cord; Degeneration of spinal cord anterior horn cells; Loss of spinal cord anterior horn cells; Progressive loss of anterior horn cells; Spinal cord anterior horn cell degeneration","HPO_Name__c":"Degeneration of anterior horn cells","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"An inadequate sucking reflex, resulting in the difficult of newborns to be breast-fed.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002033","HPO_Synonym__c":"Poor suck; Poor sucking; Sucking weakness","HPO_Name__c":"Poor suck","Feature_System__c":"Digestive System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0003324","HPO_Synonym__c":"Generalized weakness; Muscle weakness, diffuse; Muscle weakness, generalized","HPO_Name__c":"Generalized muscle weakness","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"An abnormal curvature of the spine in both a coronal (lateral) and sagittal (back-to-front) plane.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002751","HPO_Name__c":"Kyphoscoliosis","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"Fasciculations or fibrillation affecting the tongue muscle.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001308","HPO_Synonym__c":"Lingual fasciculations; Lingual fibrillations; Lingual twitching; Tongue fasciculation; Tongue fasciculations/fibrillations; Tongue twitching; Twitching of the tongue","HPO_Name__c":"Tongue fasciculations","Feature_System__c":"Nervous System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0006380","HPO_Synonym__c":"Flexion contracture of knees; Flexion contractures at both knees; Flexion contractures of knees; Flexion deformity of the knee; Knee flexion contractures; Knee flexion deformity","HPO_Name__c":"Knee flexion contracture","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Chronic loss of joint motion in an interphalangeal joint of a finger due to structural changes in non-bony tissue.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001220","HPO_Synonym__c":"Interphalangeal joint flexion contractures","HPO_Name__c":"Interphalangeal joint contracture of finger","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Chronic muscle inflammation accompanied by muscle weakness.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0009071","HPO_Name__c":"Inflammatory myopathy","Feature_System__c":"Musculoskeletal System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A facial appearance characteristic of myopathic conditions. The face appears expressionless with sunken cheeks, bilateral ptosis, and inability to elevate the corners of the mouth, due to muscle weakness.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002058","HPO_Synonym__c":"Myopathic face; Myopathic facial appearance","HPO_Name__c":"Myopathic facies","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"ORPHA:1145","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0002098","HPO_Synonym__c":"Breathing difficulties; Labored breathing; Respiratory difficulties","HPO_Name__c":"Respiratory distress","Feature_System__c":"Respiratory system","HPO_Feature_Type__c":"Symptom"}}],"tags":{"Cause":["Genetics"],"Disease Category":["Genetics","Neurology","Congenital Abnormality"],"Specialist":["Genetics","Neurology","Orthopedics","Neuromuscular medicine","Pediatrics"],"Account":["Peripheral Neuropathy","Congenital limb malformation"]},"synonyms":["amc, distal, x-linked"," arthrogryposis, x-linked, type i"," smax2"," spinal muscular atrophy with arthrogryposis"," spinal muscular atrophy, x-linked 2"," spinal muscular atrophy, x-linked 2, infantile, x-linked recessive"," spinal muscular atrophy, x-linked infantile"," spinal muscular atrophy, x-linked lethal infantile"," spinal muscular atrophy, x-linked type 2"," x-linked distal arthrogryposis multiplex congenita"," x-linked spinal muscular atrophy type 2"]}