{"orpha":1145,"name":"Infantile-onset X-linked spinal muscular atrophy","type":"Disease","group":"Disorder","status":"active","flags":[],"synonyms":["SMAX2","Spinal muscular atrophy with arthrogryposis","X-linked distal arthrogryposis multiplex congenita","X-linked spinal muscular atrophy type 2"],"definition":"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.","note":null,"url":"https://raremap.alftech.space/d/ORPHA-1145/","orphanet_url":"https://www.orpha.net/en/disease/detail/1145","names":{"fr":{"name":"Amyotrophie spinale infantile liée à l'X","synonyms":["ASX2","Amyotrophie spinale avec arthrogrypose","Amyotrophie spinale liée à l'X type 2","Arthrogrypose distale liée à l'X","SMAX2"],"definition":"Forme rare d'amyotrophie spinale caractérisée par l'apparition néonatale d'une hypotonie sévère, d'une aréflexie, d'une grande faiblesse musculaire, de multiples contractures congénitales, d'une dysmorphie faciale (visage myopathique avec une bouche entrouverte en forme de tente), d'une cryptorchidie et de légères anomalies squelettiques (cyphose, scoliose), souvent précédée d'un polyhydramnios et d'une diminution des mouvements <i>in utero</i> du foetus, et suivie de fractures osseuses survenant peu après la naissance. La faiblesse musculaire est progressive et l'atteinte des muscles thoraciques entraîne in fine une insuffisance ventilatoire et une défaillance respiratoire."},"de":{"name":"Spinale Muskelatrophie, infantile, X-chromosomale","synonyms":["SMAX2","Spinale Muskelatrophie mit Arthrogrypose","Spinale Muskelatrophie, X-chromosomale, Typ 2","X-chromosomale distale Arthrogryposis multiplex congenita"],"definition":"Eine seltene Form der spinalen Muskelatrophie, die durch das Auftreten von schwerer Hypotonie, Areflexie, ausgeprägter Schwäche, multiplen kongenitalen Kontrakturen, Gesichtsdysmorphien (myopathisches Gesicht mit offenem, zeltförmigem Mund), Kryptorchismus und leichten Skelettanomalien (z. B. Kyphose, Skoliose) im Neugeborenenalter gekennzeichnet ist. Häufig gehen Polyhydramnion und verminderte fetale Bewegungen im Mutterleib voraus, und kurz nach der Geburt treten Knochenbrüche auf. Die Muskelschwäche schreitet fort und die Beteiligung der Brustmuskulatur führt schließlich zu Ateminsuffizienz und Atemstillstand."},"es":{"name":"Atrofia muscular espinal de inicio en el lactante ligada al cromosoma X","synonyms":["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"],"definition":"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."},"it":{"name":"Artrogriposi multipla congenita distale legata all'X","synonyms":["Atrofia muscolare spinale SMAX2-correlata","Atrofia muscolare spinale con artrogriposi","Atrofia muscolare spinale infantile legata all'X","Atrofia muscolare spinale legata all'X, tipo 2","SMAX2"],"definition":"L'artrogriposi multipla congenita distale legata all'X (SMAX2) è una forma rara di atrofia muscolare spinale ad esordio neonatale caratterizzata da ipotonia grave, areflessia, debolezza grave, contratture congenite multiple, dimorfismi facciali (volto miopatico con bocca aperta ''a forma di tenda''), criptorchidismo e lievi anomalie scheletriche (cifosi, scoliosi), spesso preceduti da polidramnios e riduzione dei movimenti fetali in utero, seguiti da fratture ossee poco dopo la nascita. I pazienti spesso hanno un'aspettativa di vita ridotta, che in genere non supera i due anni, a causa della debolezza muscolare progressiva e dell'interessamento dei muscoli del torace che esita nell'insufficienza ventilatoria e respiratoria."},"nl":{"name":"Infantiele X-gebonden spinale musculaire atrofie","synonyms":["SMAX2","Spinale spieratrofie met artrogrypose","X-gebonden distale arthrogryposis multiplex congenita","X-gebonden spinale musculaire atrofie type 2","X-gebonden spinale spieratrofie type 2"],"definition":"Een zeldzame vorm van spinale musculaire atrofie, gekenmerkt door neonatale aanvang van ernstige hypotonie, areflexie, zeer ernstige zwakte, multipele congenitale contracturen, dysmorfe gelaatskenmerken (myopathisch gelaat met open, tentvormige mond), cryptorchisme, en milde skeletafwijkingen (kyfose, scoliose), vaak voorafgegaan door polyhydramnion en vermindering van foetale bewegingen <i>in utero</i> en gevolgd door botfracturen kort na de geboorte. Spierzwakte is progressief en betrokkenheid van spieren van thorax leidt uiteindelijk tot respiratoire insufficiëntie en falen."},"pt":{"name":"Atrofia muscular espinhal ligada ao X de início na infância","synonyms":["Artrogripose distal múltipla congénita ligada ao X"]},"pl":{"name":"Niemowlęcy rdzeniowy zanik mięśni sprzężony z chromosomem X","synonyms":["Dziecięcy rdzeniowy zanik mięśni sprzężony z chromosomem X","Rdzeniowy zanik mięśni zależny od SMAX2","Rdzeniowy zanik mięśni typu 2 sprzężony z chromosomem X","Rdzeniowy zanik mięśni z artrogrypozą","SMAX2","SMAX2","Rdzeniowy zanik mięśni typu 2 sprzężony z chromosomem X","Rdzeniowy zanik mięśni z artrogrypozą","Dystalna artrogrypoza sprzężona z chromosomem X"],"definition":"Rzadka postać rdzeniowego zaniku mięśni, która charakteryzuje się ciężką hipotonią obserwowaną u noworodków, brakiem odruchów, dużym osłabieniem, mnogimi wrodzonymi przykurczami, dysmorfią twarzy (miopatyczna twarz z otwartymi ustami z namiotowatym kształtem górnej wargi), wnętrostwem i łagodnymi nieprawidłowościami szkieletu (tj. kyfoza, skolioza). Często jest poprzedzona wielowodziem i osłabieniem ruchów płodu in utero, zaś krótko po urodzeniu dochodzi do złamań kości. Osłabienie mięśni postępuje, a zajęcie mięśni klatki piersiowej ostatecznie prowadzi do niewydolności oddechowej."},"cs":{"name":"X-vázaná distální arthrogryposis multiplex congenita","synonyms":["SMAX2","SMAX2-vázaná spinální svalová atrofie","Spinální svalová atrofie s artrogrypózou","X-vázaná infantilní spinální svalová atrofie","X-vázaná spinální svalová atrofie, typ 2"]},"uk":{"name":"Х-зчеплена спінальна мязова атрофія, що починається в дитинстві","synonyms":["SMAX2","Спінальна мязова атрофія з артрогрипозом","Х-зчеплений дистальний артрогрипоз множинний вроджений","Х-зчеплена спінальна мязова атрофія, тип 2"],"definition":"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."},"zh":{"name":"婴儿发病型X-连锁脊髓性肌萎缩症","synonyms":["X连锁先天性多发远端关节挛缩"]},"tr":{"name":"İnfantil başlangıçlı X'e bağlı spinal müsküler atrofi","synonyms":["SMAX2","X'e bağlı spinal kas atrofisi tip 2","Artrogripozisli spinal kas atrofisi","X'e bağlı distal artrogripozis multipleks konjenita"]}},"xrefs":[{"source":"OMIM","code":"301830","qualifier":"E","icd_relation":null,"validated":true},{"source":"ICD-10","code":"G12.1","qualifier":"NTBT","icd_relation":"attributed","validated":true},{"source":"ICD-11","code":"8B61.Y","qualifier":"NTBT","icd_relation":"attributed","validated":true},{"source":"MONDO","code":"0010532","qualifier":"E","icd_relation":null,"validated":true},{"source":"MeSH","code":"C535380","qualifier":"E","icd_relation":null,"validated":true},{"source":"UMLS","code":"C1844934","qualifier":"E","icd_relation":null,"validated":true},{"source":"GARD","code":"8521","qualifier":"E","icd_relation":null,"validated":true}],"associations":[],"incoming_associations":[],"preferential_parent":{"orpha":93890,"name":"Rare developmental defect during embryogenesis"},"parents":[{"orpha":1037,"name":"Arthrogryposis multiplex congenita","classifications":[147,156]},{"orpha":404538,"name":"X-linked distal hereditary motor neuropathy","classifications":[156,181]}],"children":[],"genes":[{"symbol":"UBA1","name":"ubiquitin like modifier activating enzyme 1","gene_type":"gene with protein product","association":"Disease-causing germline mutation(s) (loss of function) in","status":"Assessed","source":"18179898[PMID]","hgnc":"12469","ensembl":"ENSG00000130985","omim":"314370","loci":["Xp11.3"]}],"genes_via_subtypes":[],"inheritance":["X-linked recessive"],"onset":["Neonatal"],"prevalence":[{"type":"Cases/families","qualification":"Family(ies)","class":null,"value":14.0,"area":"Worldwide","status":"Validated","source":"20301739[PMID]"},{"type":"Point prevalence","qualification":"Class only","class":"<1 / 1 000 000","value":0.0,"area":"Worldwide","status":"Validated","source":"ORPHANET_20301739[PMID]"}],"phenotypes":{"validation_status":"y","online":"y","validation_date":"2021-07-16","source":"31932168[PMID]_32181232[PMID]_23518311[PMID]","terms":[{"hpo":"HP:0006802","label":"Abnormal anterior horn cell morphology","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0004303","label":"Abnormal muscle fiber morphology","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0001284","label":"Areflexia","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0002398","label":"Degeneration of anterior horn cells","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0003445","label":"EMG: neuropathic changes","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0002033","label":"Poor suck","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0003202","label":"Skeletal muscle atrophy","frequency":"Very frequent (99-80%)","criteria":null},{"hpo":"HP:0002425","label":"Anarthria","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0006466","label":"Ankle flexion contracture","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002804","label":"Arthrogryposis multiplex congenita","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0020110","label":"Bone fracture","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0000887","label":"Cupped ribs","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002987","label":"Elbow flexion contracture","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0008947","label":"Floppy infant","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0000218","label":"High palate","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0003273","label":"Hip contracture","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0009071","label":"Inflammatory myopathy","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0001220","label":"Interphalangeal joint contracture of finger","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0006380","label":"Knee flexion contracture","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002058","label":"Myopathic facies","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0003701","label":"Proximal muscle weakness","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002098","label":"Respiratory distress","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002093","label":"Respiratory insufficiency","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0000773","label":"Short ribs","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0007269","label":"Spinal muscular atrophy","frequency":"Frequent (79-30%)","criteria":null},{"hpo":"HP:0002518","label":"Abnormal periventricular white matter morphology","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0000028","label":"Cryptorchidism","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0002460","label":"Distal muscle weakness","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0001290","label":"Generalized hypotonia","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0003324","label":"Generalized muscle weakness","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0002751","label":"Kyphoscoliosis","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0008180","label":"Mildly elevated creatine kinase","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0007178","label":"Motor polyneuropathy","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0002009","label":"Potter facies","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0001308","label":"Tongue fasciculations","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0030319","label":"Weakness of facial musculature","frequency":"Occasional (29-5%)","criteria":null},{"hpo":"HP:0100543","label":"Cognitive impairment","frequency":"Very rare (<4-1%)","criteria":null}]}}