{"frequencyBands":{"HP:0040280":[100,100],"HP:0040281":[80,99],"HP:0040282":[30,79],"HP:0040283":[5,29],"HP:0040284":[1,4],"HP:0040285":[0,0]},"page":{"columns":[{"gene":"","key":"MONDO:0012368/OMIM:609924","label":"Aminoacylase 1 deficiency","mondoId":"MONDO:0012368","onsetQualifier":null,"recordKeys":["078bd4fb360f1641fcd65de3b43975fe9cdaf9d88edd6b50780183abe3a17c6e","12d3e86c2a60b61a6ba5c0e0a8d56d69f547e6bb467f750e455dbee53d33ff73","1caaceda02d65978edbd8c585af329b28bff781eecc7c32be0ac2c764e8d403d","370b7cc83f6fa56c31a705ced576cb3137855c41e4f69babb60a4a54e6c73ad3","3bed043d883897bf24de7546568925daddd42a755898eaa09ddfad4d88f6f305","5825d6e4d6b7433010d6de0e60f8b3829c66c3fb7091a977bd861f296167d171","58a2110c2c0f8d816b50bfaef5f4d6aaf967a715e09154b8d3216220986894cc","65cb39f258dccbbb5f06270507c54a37cae2d7a3cc20529f0ff00897d8c445bd","67310187d38ba28aecd785091f44067dd71775786e74f8040b8b70babb850cff","78a648912b4e82746e8ca1b0741800f16514f98c962a3fb9acc46c9846250634","82d3a3e82edb46cbfd35ea3bbc97ec58cec8bf547cb9922653189f3b2c98c04d","83e036e9d6186a7d269546acb15f504f7a2a955e100b5a1e978e9a032f534cee","8b62a609e6ba2458ac26c98bd8f93b6d49c2eadf9960a80c414c47a30ca81a05","94c2331e6e47ed8bbd7fdb3cef48edc100c051abc2c806bad58ad74cbacb31fb","9b45dc7f60f43623213197c4a6a33b37779b53fabfc7fe991850710615268d64","9ce75c85c159bb5da78476c3dc77f68c50c5a575af069a7fd358f8ab42166134","c0ad31b321e2d2d531cf1cb85be774f15aca2865df6778d2dd503d52c7318500","ec02a6c30f61e07995c5f17e5a15c72de8fd61f25b49e2b54ee389c31fb58f03"],"recordQualifiers":{},"scopeLabel":"OMIM:609924","sourceIds":["OMIM:609924"],"sourceScope":"This column retains the native source entry. It is not a pooled estimate for the umbrella condition."},{"gene":"","key":"MONDO:0012368/ORPHA:137754","label":"Aminoacylase 1 deficiency","mondoId":"MONDO:0012368","onsetQualifier":null,"recordKeys":["0956867d441909fe15891a6221213798c125c4687a8dda97e0cbdacf458a8303","10ffbad4976c94d71d5b4391e806df9c5143697b85b2b08c19b461cbc96ca8dc","218f96ccede595b806b1e40c690e9179762d938b4a0045abf314806d4e529e61","4a7a125ed4bb58d8d84e07fc6680f823f022f6fd4edcea84a0e158f74af46044","598a9d5b49c8a0ca49f15b1b9b0a43332514d911dbeaac881487b4523be2cabb","a1c1d0a9def78e87b48f0c10d2bddf5dca54d619c29e8f72832c18bd858d2a85","b1ed6d29b6b0ec6776e885ff0d5b487e07fd7c4653ec5fb9c677e5bd2a602788","bdd778a03085fdd5509a9383fface81fab09d1c20537dbbbd64e16c60ee6509d","c6747ef8673208c1850c0eb17ab59356542e57af25cb89df5d25e2505584da2a","cb44b2f9c190ee2951f21abdf787d48a0c4f8f7836b7579798bb14073dd894fc","dfe781fa11141ed68c2e3c5fb1a941f58c587246ee85af46d517f3709573c713","ed04cd613a17f78b99058fbd88ac5f4679822d1532f0bdf81ec59099c3ec4b31","faa985c07d599a20eb276fd6d4958e7f757ea99b1927cf10e3c2496008a54ef8"],"recordQualifiers":{},"scopeLabel":"ORPHA:137754","sourceIds":["ORPHA:137754"],"sourceScope":"This column retains the native source entry. It is not a pooled estimate for the umbrella condition."}],"comparison":{"collapseColumnsLabel":"Show initial comparisons","defaultColumnKeys":["MONDO:0012368/OMIM:609924","MONDO:0012368/ORPHA:137754"],"expandColumnsLabel":"Compare all source entries","intro":"Compare the original source entries. Different entries may describe different patient groups.","primaryFeatureIds":[],"scopeNoteHtml":"<p>Each column keeps its native condition scope. Initial features are displayed alphabetically, not ranked by clinical importance. Counts remain separate, and an empty cell does not mean a feature cannot occur.</p>"},"coverage":{"countRecords":8,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":31,"sourceGroups":{"omim":10,"orphanet":13,"published":8}},"features":[{"hpoId":"HP:0006846","label":"Acute encephalopathy","primary":false},{"hpoId":"HP:0006817","label":"Aplasia/Hypoplasia of the cerebellar vermis","primary":false},{"hpoId":"HP:0007370","label":"Aplasia/Hypoplasia of the corpus callosum","primary":false},{"hpoId":"HP:0002104","label":"Apnea","primary":false},{"hpoId":"HP:0002069","label":"Bilateral tonic-clonic seizure","primary":false},{"hpoId":"HP:0001662","label":"Bradycardia","primary":false},{"hpoId":"HP:0001623","label":"Breech presentation","primary":false},{"hpoId":"HP:0001272","label":"Cerebellar atrophy","primary":false},{"hpoId":"HP:0002059","label":"Cerebral atrophy","primary":false},{"hpoId":"HP:0002120","label":"Cerebral cortical atrophy","primary":false},{"hpoId":"HP:0002188","label":"Delayed CNS myelination","primary":false},{"hpoId":"HP:0001298","label":"Encephalopathy","primary":false},{"hpoId":"HP:0011968","label":"Feeding difficulties","primary":false},{"hpoId":"HP:0001290","label":"Generalized hypotonia","primary":false},{"hpoId":"HP:0003324","label":"Generalized muscle weakness","primary":false},{"hpoId":"HP:0001263","label":"Global developmental delay","primary":false},{"hpoId":"HP:0000752","label":"Hyperactivity","primary":false},{"hpoId":"HP:0000316","label":"Hypertelorism","primary":false},{"hpoId":"HP:0001252","label":"Hypotonia","primary":false},{"hpoId":"HP:0001324","label":"Muscle weakness","primary":false},{"hpoId":"HP:0001250","label":"Seizures","primary":false},{"hpoId":"HP:0000407","label":"Sensorineural hearing loss","primary":false},{"hpoId":"HP:0003396","label":"Syringomyelia","primary":false},{"hpoId":"HP:0002013","label":"Vomiting","primary":false},{"hpoId":"HP:0000431","label":"Wide nasal bridge","primary":false},{"hpoId":"HP:0000445","label":"Wide nose","primary":false}],"ledeHtml":"Aminoacylase 1 deficiency is an inherited disorder that can cause neurological problems; the pattern and severity of signs and symptoms vary widely among affected individuals. Individuals with this condition typically have delayed development of mental and motor skills (psychomotor delay). They can have movement problems, reduced muscle tone (hypotonia), mild intellectual disability, and seizures. However, some people with aminoacylase 1 deficiency have no health problems related to the condition. A key feature common to all people with aminoacylase 1 deficiency is high levels of modified protein building blocks (amino acids), called N-acetylated amino acids, in the urine.","mondoId":"MONDO:0012368","records":[{"frequencyKind":"count","key":"078bd4fb360f1641fcd65de3b43975fe9cdaf9d88edd6b50780183abe3a17c6e","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0002120","is_excluded":false,"label":"Cerebral cortical atrophy","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"range","key":"0956867d441909fe15891a6221213798c125c4687a8dda97e0cbdacf458a8303","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0006817","is_excluded":false,"label":"Aplasia/Hypoplasia of the cerebellar vermis","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"10ffbad4976c94d71d5b4391e806df9c5143697b85b2b08c19b461cbc96ca8dc","raw":{"aspect":"P","body_system":"ear","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000407","is_excluded":false,"label":"Sensorineural hearing impairment","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"12d3e86c2a60b61a6ba5c0e0a8d56d69f547e6bb467f750e455dbee53d33ff73","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0002069","is_excluded":false,"label":"Bilateral tonic-clonic seizure","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"1caaceda02d65978edbd8c585af329b28bff781eecc7c32be0ac2c764e8d403d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0001252","is_excluded":false,"label":"Hypotonia","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"218f96ccede595b806b1e40c690e9179762d938b4a0045abf314806d4e529e61","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0001252","is_excluded":false,"label":"Hypotonia","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"370b7cc83f6fa56c31a705ced576cb3137855c41e4f69babb60a4a54e6c73ad3","raw":{"aspect":"P","body_system":"prenatal","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0001623","is_excluded":false,"label":"Breech presentation","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"3bed043d883897bf24de7546568925daddd42a755898eaa09ddfad4d88f6f305","raw":{"aspect":"P","body_system":"digestive","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0011968","is_excluded":false,"label":"Feeding difficulties","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"range","key":"4a7a125ed4bb58d8d84e07fc6680f823f022f6fd4edcea84a0e158f74af46044","raw":{"aspect":"P","body_system":"respiratory","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002104","is_excluded":false,"label":"Apnea","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"5825d6e4d6b7433010d6de0e60f8b3829c66c3fb7091a977bd861f296167d171","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0001272","is_excluded":false,"label":"Cerebellar atrophy","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"58a2110c2c0f8d816b50bfaef5f4d6aaf967a715e09154b8d3216220986894cc","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":null,"hpo_id":"HP:0001263","is_excluded":false,"label":"Global developmental delay","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"598a9d5b49c8a0ca49f15b1b9b0a43332514d911dbeaac881487b4523be2cabb","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0001298","is_excluded":false,"label":"Encephalopathy","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"65cb39f258dccbbb5f06270507c54a37cae2d7a3cc20529f0ff00897d8c445bd","raw":{"aspect":"P","body_system":"eye","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000316","is_excluded":false,"label":"Hypertelorism","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"67310187d38ba28aecd785091f44067dd71775786e74f8040b8b70babb850cff","raw":{"aspect":"P","body_system":"head_and_neck","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000431","is_excluded":false,"label":"Wide nasal bridge","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"78a648912b4e82746e8ca1b0741800f16514f98c962a3fb9acc46c9846250634","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0001250","is_excluded":false,"label":"Seizure","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"82d3a3e82edb46cbfd35ea3bbc97ec58cec8bf547cb9922653189f3b2c98c04d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0001324","is_excluded":false,"label":"Muscle weakness","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"count","key":"83e036e9d6186a7d269546acb15f504f7a2a955e100b5a1e978e9a032f534cee","raw":{"aspect":"P","body_system":"cardiovascular","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0001662","is_excluded":false,"label":"Bradycardia","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"8b62a609e6ba2458ac26c98bd8f93b6d49c2eadf9960a80c414c47a30ca81a05","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0001290","is_excluded":false,"label":"Generalized hypotonia","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"94c2331e6e47ed8bbd7fdb3cef48edc100c051abc2c806bad58ad74cbacb31fb","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002188","is_excluded":false,"label":"Delayed CNS myelination","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"9b45dc7f60f43623213197c4a6a33b37779b53fabfc7fe991850710615268d64","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000752","is_excluded":false,"label":"Hyperactivity","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"count","key":"9ce75c85c159bb5da78476c3dc77f68c50c5a575af069a7fd358f8ab42166134","raw":{"aspect":"P","body_system":"ear","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0000407","is_excluded":false,"label":"Sensorineural hearing impairment","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"range","key":"a1c1d0a9def78e87b48f0c10d2bddf5dca54d619c29e8f72832c18bd858d2a85","raw":{"aspect":"P","body_system":"eye","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000316","is_excluded":false,"label":"Hypertelorism","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"b1ed6d29b6b0ec6776e885ff0d5b487e07fd7c4653ec5fb9c677e5bd2a602788","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0001250","is_excluded":false,"label":"Seizure","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"bdd778a03085fdd5509a9383fface81fab09d1c20537dbbbd64e16c60ee6509d","raw":{"aspect":"P","body_system":"head_and_neck","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000445","is_excluded":false,"label":"Wide nose","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"c0ad31b321e2d2d531cf1cb85be774f15aca2865df6778d2dd503d52c7318500","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002059","is_excluded":false,"label":"Cerebral atrophy","onset_id":null,"reference":"OMIM:609924","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"c6747ef8673208c1850c0eb17ab59356542e57af25cb89df5d25e2505584da2a","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0003324","is_excluded":false,"label":"Generalized muscle weakness","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"cb44b2f9c190ee2951f21abdf787d48a0c4f8f7836b7579798bb14073dd894fc","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0001263","is_excluded":false,"label":"Global developmental delay","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"dfe781fa11141ed68c2e3c5fb1a941f58c587246ee85af46d517f3709573c713","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003396","is_excluded":false,"label":"Syringomyelia","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"ec02a6c30f61e07995c5f17e5a15c72de8fd61f25b49e2b54ee389c31fb58f03","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:609924","disease_name":"Aminoacylase 1 deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0006846","is_excluded":false,"label":"Acute encephalopathy","onset_id":null,"reference":"PMID:16274666","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"range","key":"ed04cd613a17f78b99058fbd88ac5f4679822d1532f0bdf81ec59099c3ec4b31","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0007370","is_excluded":false,"label":"Aplasia/Hypoplasia of the corpus callosum","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"faa985c07d599a20eb276fd6d4958e7f757ea99b1927cf10e3c2496008a54ef8","raw":{"aspect":"P","body_system":"digestive","disease_id":"ORPHA:137754","disease_name":"Aminoacylase 1 deficiency","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002013","is_excluded":false,"label":"Vomiting","onset_id":null,"reference":"ORPHA:137754","source_release":"2026-06-23"},"sourceGroups":["orphanet"]}],"referenceLabels":{},"references":{"causeHtml":"<ul><li><a href=\"https://medlineplus.gov/genetics/condition/aminoacylase-1-deficiency\">Aminoacylase 1 deficiency</a></li></ul>","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"<p>Aminoacylase 1 deficiency is caused by mutations in the ACY1 gene. This gene provides instructions for making an enzyme called aminoacylase 1, which is involved in the breakdown of proteins when they are no longer needed. Many proteins in the body have an acetyl group attached to one end. This modification, called N-acetylation, helps protect and stabilize the protein. Aminoacylase 1 performs the final step in the breakdown of these proteins by removing the acetyl group from certain amino acids. The amino acids can then be recycled and used to build other proteins.</p><p>Mutations in the ACY1 gene lead to an aminoacylase 1 enzyme with little or no function. Without this enzyme&#x27;s function, acetyl groups are not efficiently removed from a subset of amino acids during the breakdown of proteins. The excess N-acetylated amino acids are released from the body in urine. It is not known how a reduction of aminoacylase 1 function leads to neurological problems in people with aminoacylase 1 deficiency.</p><p class=\"section-source\"><a href=\"https://medlineplus.gov/genetics/condition/aminoacylase-1-deficiency/#causes\">MedlinePlus Genetics: Causes</a></p>","key":"forms","title":"What causes Aminoacylase 1 deficiency?"},{"bodyHtml":"<p class=\"section-source\">Source: <a href=\"https://medlineplus.gov/genetics/condition/aminoacylase-1-deficiency\">MedlinePlus Genetics</a></p>","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"aminoacylase-1-deficiency","sourceDocuments":[{"name":"Aminoacylase 1 deficiency","reviewed":"2014-05","sections":{"causes":{"fetchedAt":"2026-10-20T20:19:20.713858+00:00","label":"Causes","pageSha256":"65fa72f0355a1909bc0b0b9ea031a7b29668649ec0a6a9ed7405577e63d362f6","sourceUrl":"https://medlineplus.gov/genetics/condition/aminoacylase-1-deficiency/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/aminoacylase-1-deficiency"}],"sourceNote":"MedlinePlus descriptions and Causes; original HPO annotations.","takeawayHtml":"Cause explanations are from MedlinePlus Genetics. Feature values below retain their original sources and patient groups.","title":"Aminoacylase 1 deficiency"},"schemaVersion":1}