{"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:0007585/OMIM:133700","label":"Exostoses, multiple, type I","mondoId":"MONDO:0007585","onsetQualifier":null,"recordKeys":["0d0eacf4eedbad36a91feb5ec6268d2c9853200474db277301051b753fbf9d60","17898d07ac3cfcc2387b802d3d6ee84aaed5ebb9724bea3d2f2b0d327b2fdf88","2d226c49952cbb8153b66bf897b95993e72e7e860e17d126f4118e24d3aec1e3","2e7d9df24397239329c6acd12a8602f012d912422b0acfa2729b8fd87bbe2ac5","405db97b09cda38a6862fc784a56198e758847b0c27483a47bb97faa46c33c55","56f79b989610acf5a0cea4d4e41feadfe0dddd0222ef509238b25f07a2e67254","73f1bcf97966ba58270d592ddc717fbb5e259958b5515f36dff7674bc6061b6d","8267a19a343d869c54028f7c560f1bd026350519ba709833cd4bd13871a6a4bd","8c2ff51a2f0c8a409b58b20b5d5106ff37cfbfd4532dfa69e455366f0885419b","ab9de69f921114eaf630d292714b7d15c50683ef21cca8fe4f76891a66adecb6","b294d337bca248e48045aef72204313b96c144d74f75f923090a238bf9a41498","ce0be7f88988fa2a2da3bdbc38e3444b6045b1befbe6715e23ade6558e1eda05","e4d881205f3e1a38cd94f72a2c028b742a6e6d56fb7c537074ee97185fb43bea"],"recordQualifiers":{},"scopeLabel":"OMIM:133700","sourceIds":["OMIM:133700"],"sourceScope":"This column retains the native source entry. It is not a pooled estimate for the umbrella condition."},{"gene":"","key":"MONDO:0007586/OMIM:133701","label":"Exostoses, multiple, type II","mondoId":"MONDO:0007586","onsetQualifier":null,"recordKeys":["25b3ddb2890bb64bca970e46ca7216a6fd4c371105e96cbab077ae2db1801b71","37e356bd3e81ebb439c9fe516e72529716f5b6ea6e6f31eceb7b77336538db75","5dd581c2614b35dc2769a0c37cb5630495ab558eaa58cbafbad3b3256bdcbe2e","6104743838b385e5e22ce31ad67ebf2c62769eb66e678397b28a1f5d4e1a1353","65ffa39f589320090c729560bdbc01277679d64cd20a750f3d8d59d2bdf465fa","a1757312db91fb52dd9be7578a6af336b932535893ddaf4cd04700490609428a","c44c25b8239b8ece26b36afcc56a715bea41fa72f76aea497316e3f5b62863a6","ca574cb8fe4d8c16f052373f9306965b2b3b142ec0ac91bd552ed7148d44047d","d23afc4fc2b8cb8fa7e147d362076b24858a0c62c61406590d80e5772cb51df6","d769b9b9f2494f130c476c3ae171dbf09fa595c5124169107207756c980505cc","e3dd6b1306054c86ac725e352d99cea15f1e4fe05cf58da8b7be001689e99fd1","e8296a6b2acac7518f2471d1f657c8a3e6e249f0cd872ca1268776d131f3c3c0","e872a26cb7031d1ea232f5aad64b8dd1363739657e85bea1847cb13d5b373d36"],"recordQualifiers":{},"scopeLabel":"OMIM:133701","sourceIds":["OMIM:133701"],"sourceScope":"This column retains the native source entry. It is not a pooled estimate for the umbrella condition."},{"gene":"","key":"MONDO:0010846/OMIM:600209","label":"Exostoses, multiple, type III","mondoId":"MONDO:0010846","onsetQualifier":null,"recordKeys":["ebcfa669cb5a9b64a2f4febeaa18601a65dd23e4f4fccca19f70d912ca10e305"],"recordQualifiers":{},"scopeLabel":"OMIM:600209","sourceIds":["OMIM:600209"],"sourceScope":"This column retains the native source entry. It is not a pooled estimate for the umbrella condition."},{"gene":"","key":"MONDO:0005508/ORPHA:321","label":"Multiple osteochondromas","mondoId":"MONDO:0005508","onsetQualifier":null,"recordKeys":["003a54308a9473be798915e7b27d3e5f5602bcee37b6aee8d285627cd07a8d05","04360c94f8fdbaede989edb7b5fa7ee064f54018b90ff3e76ef0cce8c01106f1","0639f4f1c152836c12c7dfe13dfa67c165de3f283b5c3effe748eb86b62437b1","07c874d839255f384746c511cfc3621dae4ad0aeda71f8f69231ee771d99be23","0fa4a686c21a3f9c1e9013bf3069dd324f039b440fa2742770138c9cd31ce2ad","1071969fe6c05e412fa6575f92c43fd6fe6e0c5225a4f4db0abefd7e863234ec","1c1b881fdc8d31fe47a280c694aaafee40f939dbd6bc4ec9624b0942cc24b458","1e0cd07f72161cc5c6e9ddb862ad0ab0de83761b8adebf6b72761ec8ab4d0c66","200f084f9fffdde5927096eecd91b0d90b31ec67ffb90c422030ab2d2376cc3d","241a80ce17d50b457f1ef3e583b91ad1beb1b25f8f665810212e046510ce50a8","269ee00f3143fbc98d503589d248ffe62fdb4d7e8357b60bff10a7d4ff6e40db","28cd4e73e8e71760c317eb14fcacf08001ace9d061ebd69ff87ef84c71169f6e","2ee311008329a0cde6623d6ffedec6f9d6ccd589d1d444c48fccf34f2ed111fb","34f48659663a186f41573e3afef9552a7f9d2570e75d7c771fb2a7318ac03abe","3bfa35cc175b3bc584c474b423c9db260d53c4ef0233d01aa062e13c3e98d9d8","406684ceec387cca01c78f456be9544b6c784cdefaafd8e34ff3b3c2f67b235b","44ef3f7d1ed3ca8eeac97c642366d380db5af58732729c176f943ce7b3c7832e","4e3c372dc2751c0517880ee59aef30196578425730b75d9bb8fec7486b459153","551e27d244247a984ee17faec154ce1fabefa71a9ef6cbe663691515db6d87cc","569930eb660b46e9af98b609b1181469b9eb6fcf5b9e327f0e0e70dde347d26d","5fe653f34a39527dab2ce555652438f616fabda6b101617089c3865ce1c39ad0","68d4af753a317bd0a01294ed8caa61fafbda5b838dcdfd88a544462c3fce669d","70bb6921e6924aea47ec864b5364556c606da897e4875cb25934b5b45a46f0a6","770e4daa22c55fb7139e93d2e9aaa22ede59dfa21dffc9a7708acbdb274c53df","7964c170ffc8103fe005c200dd5c761223de65488e0a7265ab87c70cc1b2f54c","79d36c2ade09996fa7daca2f2f6d9684c067a7c77d09852575071365661e01fe","7ebd584f011bf1c12f5c8437c0cb85bfd1506b563588fe1f44c7ee3f89170fd2","8222cfa797e193ebddd5f4b90422d59502459534fce2cbed1e9186b1a571d4b3","83e2ff84cbbe5753ec00ade6c2d56795d317e7b1f57f9b721d87b0cfdac00cc1","83e4516f8eb10f650827c9df99f7f71eeeb3067a4e9acd750203468a97496fc6","854f5d95440e4f2bf8750476a42a72819c1d95bb028b99f9c622c6e10cff96a7","9091da52a470b5921133ea7a57b66d8ba82a5bc6b02172b4c1b03eccd0ab1b5f","91a791e8ca1ac288ea5a1734c3d6544971368b913170b17bce87391991d59b4d","94f734df542366cfa21bfd1a588814164b42fc1867439ed791d08d984ee392d0","958a4c9ac5b8a15178f249335e206d54ba3e2340e9163529e1cf2b2b5b7558b8","969cc8636252b94d7e24e59af079c3612ba19aa428249300df53f2dfba9799ed","985a9e1e83c28f3ba526715e4a59335d0c9ee755d4c025e2c07d0ca3b58a8988","9a7477091d94763e80ad2d6c97cf95607fa6651711035bed03ab050675def48c","9a8008749c4bfba41c42d616cd77307d5f857583e4485bb190e41251539a842e","9d632e7a1b7f8b59acafb5894022e322c87152297450f16dddd3a1c5750c8c89","a8c9b2737ca4ae3f87020b964488931e058a8fc1b8a1f8ccba709f66fd2a3cb6","aac972a5faaffeb175497beb382aa0f9ed64bb30be8270d559d649cfce2296c6","add0fd8b83496781403519310afc3ad38039164b5e91e65334b3ca56d18e2240","ae4e266aac851a463ad49e5ea2522630c8b9f16d256b93e91e111289f4c976a2","aee5f5b6db113b375d61691545e51a49daf6a162fced4e66cffc429a77809202","b3baa49b85b2c1afc8fc4431e4cbbb7b3249ea9fa58c6da448b9b723dd7ab62c","b4c4d99e1c48f78975b0ab8794b9dd9d4d2ad67a528b72ce83532290836db710","b8125addebaf27237ac88ce9692200e3c0196b5c0be18ffbcc62c83ea0ac940b","bc43d26b9cd6f35863e77da100e48c2117455c68e324c77c7f3941d9e1a17aea","cf48a24e0d10c908d24426382468bbb4d57b40aa94cd0bb30617a7a8448c77b4","d6186caca9cb7822fcd4aeeadeeac5fce7b04dc8c144bc6256182e3d51f44224","dce7d7ead7b0e347a16643449e082a4a9d37232fc6a357978d47fa1926198960","e1ec48ca9090114e7cfa0e79f287a7ed6a9e8586c18642e4ccb1a57340096c4e","edc988cdbb34cfcb410ff10fe58f4681a92983e8b9b62d5921afae4bc9b209c5","f0c254eeb2864196d74741715229e9df74a1532ef2d52df7e4679459b085decb","f5e2a482fe0cda14d70eaff892db3345ac891ad4a90b9b234994e988ee0554c0"],"recordQualifiers":{},"scopeLabel":"ORPHA:321","sourceIds":["ORPHA:321"],"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:0007585/OMIM:133700","MONDO:0007586/OMIM:133701","MONDO:0010846/OMIM:600209","MONDO:0005508/ORPHA:321"],"expandColumnsLabel":"Compare all source entries","intro":"Compare the original source entries. Different entries may describe different patient groups.","primaryFeatureIds":[],"scopeNoteHtml":"

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.

"},"coverage":{"countRecords":6,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":83,"sourceGroups":{"omim":22,"orphanet":56,"published":5}},"features":[{"hpoId":"HP:0003330","label":"Abnormal bone structure","primary":false},{"hpoId":"HP:0001191","label":"Abnormal carpal morphology","primary":false},{"hpoId":"HP:0002763","label":"Abnormal cartilage morphology","primary":false},{"hpoId":"HP:0002823","label":"Abnormal femur morphology","primary":false},{"hpoId":"HP:0002991","label":"Abnormal fibula morphology","primary":false},{"hpoId":"HP:0005922","label":"Abnormal hand morphology","primary":false},{"hpoId":"HP:0040069","label":"Abnormal lower limb bone morphology","primary":false},{"hpoId":"HP:0040071","label":"Abnormal morphology of ulna","primary":false},{"hpoId":"HP:0040163","label":"Abnormal pelvis bone morphology","primary":false},{"hpoId":"HP:0002992","label":"Abnormal tibia morphology","primary":false},{"hpoId":"HP:0002815","label":"Abnormality of the knee","primary":false},{"hpoId":"HP:0001850","label":"Abnormality of the tarsal bones","primary":false},{"hpoId":"HP:0001369","label":"Arthritis","primary":false},{"hpoId":"HP:0100555","label":"Asymmetric growth","primary":false},{"hpoId":"HP:0020110","label":"Bone fracture","primary":false},{"hpoId":"HP:0006487","label":"Bowing of the long bones","primary":false},{"hpoId":"HP:0025232","label":"Bursitis","primary":false},{"hpoId":"HP:0002318","label":"Cervical myelopathy","primary":false},{"hpoId":"HP:0100749","label":"Chest pain","primary":false},{"hpoId":"HP:0006765","label":"Chondrosarcoma","primary":false},{"hpoId":"HP:0002673","label":"Coxa valga","primary":false},{"hpoId":"HP:0002812","label":"Coxa vara","primary":false},{"hpoId":"HP:0003959","label":"Deformed forearm bones","primary":false},{"hpoId":"HP:0003977","label":"Deformed radius","primary":false},{"hpoId":"HP:0002015","label":"Dysphagia","primary":false},{"hpoId":"HP:0030883","label":"Femoroacetabular impingement","primary":false},{"hpoId":"HP:0009821","label":"Forearm undergrowth","primary":false},{"hpoId":"HP:0004302","label":"Functional motor deficit","primary":false},{"hpoId":"HP:0002857","label":"Genu valgum","primary":false},{"hpoId":"HP:0012151","label":"Hemothorax","primary":false},{"hpoId":"HP:0005214","label":"Intestinal obstruction","primary":false},{"hpoId":"HP:0009826","label":"Limb undergrowth","primary":false},{"hpoId":"HP:0001376","label":"Limitation of joint mobility","primary":false},{"hpoId":"HP:0010501","label":"Limitation of knee mobility","primary":false},{"hpoId":"HP:0008800","label":"Limited hip movement","primary":false},{"hpoId":"HP:0100559","label":"Lower limb asymmetry","primary":false},{"hpoId":"HP:0003068","label":"Madelung-like forearm deformities","primary":false},{"hpoId":"HP:0003016","label":"Metaphyseal widening","primary":false},{"hpoId":"HP:0002762","label":"Multiple exostoses","primary":false},{"hpoId":"HP:0003326","label":"Myalgia","primary":false},{"hpoId":"HP:0008443","label":"Neuropathic spinal arthropathy","primary":false},{"hpoId":"HP:0030431","label":"Osteochondroma","primary":false},{"hpoId":"HP:0012531","label":"Pain","primary":false},{"hpoId":"HP:0003276","label":"Pelvic bone exostoses","primary":false},{"hpoId":"HP:0003406","label":"Peripheral nerve compression","primary":false},{"hpoId":"HP:0002107","label":"Pneumothorax","primary":false},{"hpoId":"HP:0003105","label":"Protuberances at ends of long bones","primary":false},{"hpoId":"HP:0031625","label":"Pseudoaneurysm","primary":false},{"hpoId":"HP:0000896","label":"Rib exostoses","primary":false},{"hpoId":"HP:0000918","label":"Scapular exostoses","primary":false},{"hpoId":"HP:0003026","label":"Short long bone","primary":false},{"hpoId":"HP:0006385","label":"Short lower limbs","primary":false},{"hpoId":"HP:0010049","label":"Short metacarpal","primary":false},{"hpoId":"HP:0004322","label":"Short stature","primary":false},{"hpoId":"HP:0003474","label":"Somatic sensory dysfunction","primary":false},{"hpoId":"HP:0002176","label":"Spinal cord compression","primary":false},{"hpoId":"HP:0003396","label":"Syringomyelia","primary":false},{"hpoId":"HP:0004684","label":"Talipes valgus","primary":false},{"hpoId":"HP:0032510","label":"Tendon pain","primary":false},{"hpoId":"HP:0002144","label":"Tethered cord","primary":false},{"hpoId":"HP:0000016","label":"Urinary retention","primary":false}],"ledeHtml":"Hereditary multiple osteochondromas is a condition in which people develop multiple benign (noncancerous) bone tumors called osteochondromas. The number of osteochondromas and the bones on which they are located vary greatly among affected individuals. The osteochondromas are not present at birth, but approximately 96 percent of affected people develop multiple osteochondromas by the time they are 12 years old. Osteochondromas typically form at the end of long bones and on flat bones such as the hip and shoulder blade.","mondoId":"MONDO:0005508","records":[{"frequencyKind":"range","key":"003a54308a9473be798915e7b27d3e5f5602bcee37b6aee8d285627cd07a8d05","raw":{"aspect":"P","body_system":"genitourinary","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000016","is_excluded":false,"label":"Urinary retention","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"04360c94f8fdbaede989edb7b5fa7ee064f54018b90ff3e76ef0cce8c01106f1","raw":{"aspect":"P","body_system":"growth","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0004322","is_excluded":false,"label":"Short stature","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"0639f4f1c152836c12c7dfe13dfa67c165de3f283b5c3effe748eb86b62437b1","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0040071","is_excluded":false,"label":"Abnormal morphology of ulna","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"07c874d839255f384746c511cfc3621dae4ad0aeda71f8f69231ee771d99be23","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0001191","is_excluded":false,"label":"Abnormal carpal morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"0d0eacf4eedbad36a91feb5ec6268d2c9853200474db277301051b753fbf9d60","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"PCS","frequency_raw":"38/38","hpo_id":"HP:0002762","is_excluded":false,"label":"Multiple exostoses","onset_id":null,"reference":"PMID:11432960;PMID:34012378;PMID:35106951","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"range","key":"0fa4a686c21a3f9c1e9013bf3069dd324f039b440fa2742770138c9cd31ce2ad","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0008800","is_excluded":false,"label":"Limited hip movement","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"1071969fe6c05e412fa6575f92c43fd6fe6e0c5225a4f4db0abefd7e863234ec","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0006765","is_excluded":false,"label":"Chondrosarcoma","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"17898d07ac3cfcc2387b802d3d6ee84aaed5ebb9724bea3d2f2b0d327b2fdf88","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002318","is_excluded":false,"label":"Cervical myelopathy","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"1c1b881fdc8d31fe47a280c694aaafee40f939dbd6bc4ec9624b0942cc24b458","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0040163","is_excluded":false,"label":"Abnormal pelvis bone morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"1e0cd07f72161cc5c6e9ddb862ad0ab0de83761b8adebf6b72761ec8ab4d0c66","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0002176","is_excluded":false,"label":"Spinal cord compression","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"200f084f9fffdde5927096eecd91b0d90b31ec67ffb90c422030ab2d2376cc3d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0001369","is_excluded":false,"label":"Arthritis","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"241a80ce17d50b457f1ef3e583b91ad1beb1b25f8f665810212e046510ce50a8","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0009821","is_excluded":false,"label":"Forearm undergrowth","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"25b3ddb2890bb64bca970e46ca7216a6fd4c371105e96cbab077ae2db1801b71","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003276","is_excluded":false,"label":"Pelvic bone exostoses","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"269ee00f3143fbc98d503589d248ffe62fdb4d7e8357b60bff10a7d4ff6e40db","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0030883","is_excluded":false,"label":"Femoroacetabular impingement","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"28cd4e73e8e71760c317eb14fcacf08001ace9d061ebd69ff87ef84c71169f6e","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0004302","is_excluded":false,"label":"Functional motor deficit","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"2d226c49952cbb8153b66bf897b95993e72e7e860e17d126f4118e24d3aec1e3","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"PCS","frequency_raw":"7/37","hpo_id":"HP:0006765","is_excluded":false,"label":"Chondrosarcoma","onset_id":null,"reference":"PMID:11432960;PMID:34012378;PMID:35106951","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"2e7d9df24397239329c6acd12a8602f012d912422b0acfa2729b8fd87bbe2ac5","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000918","is_excluded":false,"label":"Scapular exostoses","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"2ee311008329a0cde6623d6ffedec6f9d6ccd589d1d444c48fccf34f2ed111fb","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0003959","is_excluded":false,"label":"Deformed forearm bones","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"34f48659663a186f41573e3afef9552a7f9d2570e75d7c771fb2a7318ac03abe","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040280","hpo_id":"HP:0030431","is_excluded":false,"label":"Osteochondroma","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"37e356bd3e81ebb439c9fe516e72529716f5b6ea6e6f31eceb7b77336538db75","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0010049","is_excluded":false,"label":"Short metacarpal","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"3bfa35cc175b3bc584c474b423c9db260d53c4ef0233d01aa062e13c3e98d9d8","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0003396","is_excluded":false,"label":"Syringomyelia","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"405db97b09cda38a6862fc784a56198e758847b0c27483a47bb97faa46c33c55","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003105","is_excluded":false,"label":"Protuberances at ends of long bones","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"406684ceec387cca01c78f456be9544b6c784cdefaafd8e34ff3b3c2f67b235b","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0006487","is_excluded":false,"label":"Bowing of the long bones","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"44ef3f7d1ed3ca8eeac97c642366d380db5af58732729c176f943ce7b3c7832e","raw":{"aspect":"P","body_system":"other","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003326","is_excluded":false,"label":"Myalgia","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"4e3c372dc2751c0517880ee59aef30196578425730b75d9bb8fec7486b459153","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0002318","is_excluded":false,"label":"Cervical myelopathy","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"551e27d244247a984ee17faec154ce1fabefa71a9ef6cbe663691515db6d87cc","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002991","is_excluded":false,"label":"Abnormal fibula morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"569930eb660b46e9af98b609b1181469b9eb6fcf5b9e327f0e0e70dde347d26d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002673","is_excluded":false,"label":"Coxa valga","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"count","key":"56f79b989610acf5a0cea4d4e41feadfe0dddd0222ef509238b25f07a2e67254","raw":{"aspect":"P","body_system":"growth","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"PCS","frequency_raw":"1/27","hpo_id":"HP:0004322","is_excluded":false,"label":"Short stature","onset_id":null,"reference":"PMID:11432960","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"5dd581c2614b35dc2769a0c37cb5630495ab558eaa58cbafbad3b3256bdcbe2e","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000896","is_excluded":false,"label":"Rib exostoses","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"5fe653f34a39527dab2ce555652438f616fabda6b101617089c3865ce1c39ad0","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0001850","is_excluded":false,"label":"Abnormality of the tarsal bones","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"6104743838b385e5e22ce31ad67ebf2c62769eb66e678397b28a1f5d4e1a1353","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002318","is_excluded":false,"label":"Cervical myelopathy","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"65ffa39f589320090c729560bdbc01277679d64cd20a750f3d8d59d2bdf465fa","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000918","is_excluded":false,"label":"Scapular exostoses","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"68d4af753a317bd0a01294ed8caa61fafbda5b838dcdfd88a544462c3fce669d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0002763","is_excluded":false,"label":"Abnormal cartilage morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"70bb6921e6924aea47ec864b5364556c606da897e4875cb25934b5b45a46f0a6","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0003330","is_excluded":false,"label":"Abnormal bone structure","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"73f1bcf97966ba58270d592ddc717fbb5e259958b5515f36dff7674bc6061b6d","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003406","is_excluded":false,"label":"Peripheral nerve compression","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"770e4daa22c55fb7139e93d2e9aaa22ede59dfa21dffc9a7708acbdb274c53df","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0009826","is_excluded":false,"label":"Limb undergrowth","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"7964c170ffc8103fe005c200dd5c761223de65488e0a7265ab87c70cc1b2f54c","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002992","is_excluded":false,"label":"Abnormal tibia morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"79d36c2ade09996fa7daca2f2f6d9684c067a7c77d09852575071365661e01fe","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0006385","is_excluded":false,"label":"Short lower limbs","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"7ebd584f011bf1c12f5c8437c0cb85bfd1506b563588fe1f44c7ee3f89170fd2","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0003406","is_excluded":false,"label":"Peripheral nerve compression","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"8222cfa797e193ebddd5f4b90422d59502459534fce2cbed1e9186b1a571d4b3","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003474","is_excluded":false,"label":"Somatic sensory dysfunction","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"8267a19a343d869c54028f7c560f1bd026350519ba709833cd4bd13871a6a4bd","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000896","is_excluded":false,"label":"Rib exostoses","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"83e2ff84cbbe5753ec00ade6c2d56795d317e7b1f57f9b721d87b0cfdac00cc1","raw":{"aspect":"P","body_system":"other","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0032510","is_excluded":false,"label":"Tendon pain","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"83e4516f8eb10f650827c9df99f7f71eeeb3067a4e9acd750203468a97496fc6","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000918","is_excluded":false,"label":"Scapular exostoses","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"854f5d95440e4f2bf8750476a42a72819c1d95bb028b99f9c622c6e10cff96a7","raw":{"aspect":"P","body_system":"respiratory","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0002107","is_excluded":false,"label":"Pneumothorax","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"8c2ff51a2f0c8a409b58b20b5d5106ff37cfbfd4532dfa69e455366f0885419b","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003068","is_excluded":false,"label":"Madelung-like forearm deformities","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"9091da52a470b5921133ea7a57b66d8ba82a5bc6b02172b4c1b03eccd0ab1b5f","raw":{"aspect":"P","body_system":"other","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0100749","is_excluded":false,"label":"Chest pain","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"91a791e8ca1ac288ea5a1734c3d6544971368b913170b17bce87391991d59b4d","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0100559","is_excluded":false,"label":"Lower limb asymmetry","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"94f734df542366cfa21bfd1a588814164b42fc1867439ed791d08d984ee392d0","raw":{"aspect":"P","body_system":"digestive","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0005214","is_excluded":false,"label":"Intestinal obstruction","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"958a4c9ac5b8a15178f249335e206d54ba3e2340e9163529e1cf2b2b5b7558b8","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0010501","is_excluded":false,"label":"Limitation of knee mobility","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"969cc8636252b94d7e24e59af079c3612ba19aa428249300df53f2dfba9799ed","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0008443","is_excluded":false,"label":"Neuropathic spinal arthropathy","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"985a9e1e83c28f3ba526715e4a59335d0c9ee755d4c025e2c07d0ca3b58a8988","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0001376","is_excluded":false,"label":"Limitation of joint mobility","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"9a7477091d94763e80ad2d6c97cf95607fa6651711035bed03ab050675def48c","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0002823","is_excluded":false,"label":"Abnormal femur morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"9a8008749c4bfba41c42d616cd77307d5f857583e4485bb190e41251539a842e","raw":{"aspect":"P","body_system":"growth","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0100555","is_excluded":false,"label":"Asymmetric growth","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"9d632e7a1b7f8b59acafb5894022e322c87152297450f16dddd3a1c5750c8c89","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0010049","is_excluded":false,"label":"Short metacarpal","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"a1757312db91fb52dd9be7578a6af336b932535893ddaf4cd04700490609428a","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003406","is_excluded":false,"label":"Peripheral nerve compression","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"a8c9b2737ca4ae3f87020b964488931e058a8fc1b8a1f8ccba709f66fd2a3cb6","raw":{"aspect":"P","body_system":"respiratory","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0012151","is_excluded":false,"label":"Hemothorax","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"aac972a5faaffeb175497beb382aa0f9ed64bb30be8270d559d649cfce2296c6","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0002857","is_excluded":false,"label":"Genu valgum","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"ab9de69f921114eaf630d292714b7d15c50683ef21cca8fe4f76891a66adecb6","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0010049","is_excluded":false,"label":"Short metacarpal","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"add0fd8b83496781403519310afc3ad38039164b5e91e65334b3ca56d18e2240","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003977","is_excluded":false,"label":"Deformed radius","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"ae4e266aac851a463ad49e5ea2522630c8b9f16d256b93e91e111289f4c976a2","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0040069","is_excluded":false,"label":"Abnormal lower limb bone morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"aee5f5b6db113b375d61691545e51a49daf6a162fced4e66cffc429a77809202","raw":{"aspect":"P","body_system":"other","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0012531","is_excluded":false,"label":"Pain","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"b294d337bca248e48045aef72204313b96c144d74f75f923090a238bf9a41498","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003276","is_excluded":false,"label":"Pelvic bone exostoses","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"b3baa49b85b2c1afc8fc4431e4cbbb7b3249ea9fa58c6da448b9b723dd7ab62c","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040282","hpo_id":"HP:0002815","is_excluded":false,"label":"Abnormality of the knee","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"b4c4d99e1c48f78975b0ab8794b9dd9d4d2ad67a528b72ce83532290836db710","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0020110","is_excluded":false,"label":"Bone fracture","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"b8125addebaf27237ac88ce9692200e3c0196b5c0be18ffbcc62c83ea0ac940b","raw":{"aspect":"P","body_system":"cardiovascular","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0031625","is_excluded":false,"label":"Pseudoaneurysm","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"bc43d26b9cd6f35863e77da100e48c2117455c68e324c77c7f3941d9e1a17aea","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0004684","is_excluded":false,"label":"Talipes valgus","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"c44c25b8239b8ece26b36afcc56a715bea41fa72f76aea497316e3f5b62863a6","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003068","is_excluded":false,"label":"Madelung-like forearm deformities","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"count","key":"ca574cb8fe4d8c16f052373f9306965b2b3b142ec0ac91bd552ed7148d44047d","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"PCS","frequency_raw":"1/18","hpo_id":"HP:0006765","is_excluded":false,"label":"Chondrosarcoma","onset_id":null,"reference":"PMID:8782816;PMID:11432960","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"ce0be7f88988fa2a2da3bdbc38e3444b6045b1befbe6715e23ade6558e1eda05","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002812","is_excluded":false,"label":"Coxa vara","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"cf48a24e0d10c908d24426382468bbb4d57b40aa94cd0bb30617a7a8448c77b4","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003026","is_excluded":false,"label":"Short long bone","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"d23afc4fc2b8cb8fa7e147d362076b24858a0c62c61406590d80e5772cb51df6","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003105","is_excluded":false,"label":"Protuberances at ends of long bones","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"d6186caca9cb7822fcd4aeeadeeac5fce7b04dc8c144bc6256182e3d51f44224","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0003016","is_excluded":false,"label":"Metaphyseal widening","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"d769b9b9f2494f130c476c3ae171dbf09fa595c5124169107207756c980505cc","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002857","is_excluded":false,"label":"Genu valgum","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"dce7d7ead7b0e347a16643449e082a4a9d37232fc6a357978d47fa1926198960","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0002015","is_excluded":false,"label":"Dysphagia","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"e1ec48ca9090114e7cfa0e79f287a7ed6a9e8586c18642e4ccb1a57340096c4e","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0000896","is_excluded":false,"label":"Rib exostoses","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"reported","key":"e3dd6b1306054c86ac725e352d99cea15f1e4fe05cf58da8b7be001689e99fd1","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002812","is_excluded":false,"label":"Coxa vara","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"e4d881205f3e1a38cd94f72a2c028b742a6e6d56fb7c537074ee97185fb43bea","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:133700","disease_name":"Exostoses, multiple, type I","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002857","is_excluded":false,"label":"Genu valgum","onset_id":null,"reference":"OMIM:133700","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"count","key":"e8296a6b2acac7518f2471d1f657c8a3e6e249f0cd872ca1268776d131f3c3c0","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"PCS","frequency_raw":"17/17","hpo_id":"HP:0002762","is_excluded":false,"label":"Multiple exostoses","onset_id":null,"reference":"PMID:8782816;PMID:11432960","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"e872a26cb7031d1ea232f5aad64b8dd1363739657e85bea1847cb13d5b373d36","raw":{"aspect":"P","body_system":"growth","disease_id":"OMIM:133701","disease_name":"Exostoses, multiple, type II","evidence":"IEA","frequency_raw":"0/10","hpo_id":"HP:0004322","is_excluded":true,"label":"Short stature","onset_id":null,"reference":"OMIM:133701","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"ebcfa669cb5a9b64a2f4febeaa18601a65dd23e4f4fccca19f70d912ca10e305","raw":{"aspect":"P","body_system":"neoplasm","disease_id":"OMIM:600209","disease_name":"Exostoses, multiple, type III","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0002762","is_excluded":false,"label":"Multiple exostoses","onset_id":null,"reference":"OMIM:600209","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"range","key":"edc988cdbb34cfcb410ff10fe58f4681a92983e8b9b62d5921afae4bc9b209c5","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0025232","is_excluded":false,"label":"Bursitis","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"f0c254eeb2864196d74741715229e9df74a1532ef2d52df7e4679459b085decb","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040283","hpo_id":"HP:0005922","is_excluded":false,"label":"Abnormal hand morphology","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]},{"frequencyKind":"range","key":"f5e2a482fe0cda14d70eaff892db3345ac891ad4a90b9b234994e988ee0554c0","raw":{"aspect":"P","body_system":"nervous_system","disease_id":"ORPHA:321","disease_name":"Multiple osteochondromas","evidence":"TAS","frequency_raw":"HP:0040284","hpo_id":"HP:0002144","is_excluded":false,"label":"Tethered cord","onset_id":null,"reference":"ORPHA:321","source_release":"2026-06-23"},"sourceGroups":["orphanet"]}],"referenceLabels":{},"references":{"causeHtml":"","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"

Changes in the EXT1 and EXT2 genes cause hereditary multiple osteochondromas. Genetic changes that cause disease are called pathogenic variants. The EXT1 and EXT2 genes provide instructions for producing the proteins exostosin-1 and exostosin-2, respectively. The two exostosin proteins bind together and form a complex found in a cell structure called the Golgi apparatus, which modifies newly produced enzymes and other proteins. In the Golgi apparatus, the exostosin-1 and exostosin-2 complex modifies a protein called heparan sulfate so it can be used by the cell. Heparan sulfate is involved in regulating a variety of body processes, including bone formation (ossification) and the growth and specialization (differentiation) of cartilage-forming cells called chondrocytes.

The pathogenic variants in the EXT1 or EXT2 gene that cause hereditary multiple osteochondromas cause cells to produce of an exostosin-1 or exostosin-2 protein that cannot process heparan sulfate correctly. A lack functional heparan sulfate likely disrupts the processes of ossification and chondrocyte differentiation and causes osteochondromas to form.

If this condition is caused by a pathogenic variant in the EXT1 gene, it is called hereditary multiple osteochondromas type 1. A pathogenic variant in the EXT2 gene causes hereditary multiple osteochondromas type 2. While both type 1 and type 2 involve multiple osteochondromas, pathogenic variants in the EXT1 gene likely account for 65 to 70 percent of all cases of hereditary multiple osteochondromas, and the severity of the symptoms seems to be greater in people with type 1 than in those with type 2.

Researchers estimate that about 10 to 15 percent of people with hereditary multiple osteochondromas do not have a pathogenic variant in either the EXT1 or the EXT2 gene. It is not known what causes hereditary multiple osteochondromas in these individuals.

MedlinePlus Genetics: Causes

","key":"forms","title":"What causes Hereditary multiple osteochondromas?"},{"bodyHtml":"

Multiple osteochondromas can disrupt bone growth and can cause growth disturbances of the arms, hands, and legs, leading to short stature. Often these problems with bone growth do not affect the right and left limb equally, resulting in uneven limb lengths (limb length discrepancy). Bowing of the forearm or ankle and abnormal development of the hip joints (hip dysplasia) caused by osteochondromas can lead to difficulty walking and general discomfort. Multiple osteochondromas may also result in pain, limited range of joint movement, and pressure on nerves, blood vessels, the spinal cord, and tissues surrounding the osteochondromas.

Osteochondromas are typically benign; however, in some instances these tumors become malignant (cancerous). Researchers estimate that people with hereditary multiple osteochondromas have a 1 in 20 to 1 in 200 lifetime risk of developing cancerous osteochondromas (called sarcomas).

Source: MedlinePlus Genetics

","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"hereditary-multiple-osteochondromas","sourceDocuments":[{"name":"Hereditary multiple osteochondromas","reviewed":"2007-12","sections":{"causes":{"fetchedAt":"2026-10-20T20:22:08.481755+00:00","label":"Causes","pageSha256":"d3495dc021ce88c81d4bb41068f87320f571d77e7fec6439d7141b7ae9a7fb51","sourceUrl":"https://medlineplus.gov/genetics/condition/hereditary-multiple-osteochondromas/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/hereditary-multiple-osteochondromas"}],"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":"Hereditary multiple osteochondromas"},"schemaVersion":1}