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":2,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":11,"sourceGroups":{"omim":9,"orphanet":0,"published":2}},"features":[{"hpoId":"HP:0003011","label":"Abnormality of the musculature","primary":false},{"hpoId":"HP:0000978","label":"Bruising susceptibility","primary":false},{"hpoId":"HP:0001905","label":"Congenital thrombocytopenia","primary":false},{"hpoId":"HP:0005537","label":"Decreased mean platelet volume","primary":false},{"hpoId":"HP:0000964","label":"Eczematoid dermatitis","primary":false},{"hpoId":"HP:0000421","label":"Epistaxis","primary":false},{"hpoId":"HP:0003261","label":"Increased circulating IgA concentration","primary":false},{"hpoId":"HP:0003212","label":"Increased circulating IgE concentration","primary":false},{"hpoId":"HP:0004854","label":"Intermittent thrombocytopenia","primary":false},{"hpoId":"HP:0005261","label":"Joint hemorrhage","primary":false},{"hpoId":"HP:0000967","label":"Petechiae","primary":false}],"ledeHtml":"X-linked thrombocytopenia is a bleeding disorder that primarily affects males. This condition is characterized by a blood cell abnormality called thrombocytopenia, which is a shortage in the number of blood cells involved in clotting (platelets). Affected individuals often have abnormally small platelets as well, a condition called microthrombocytopenia. X-linked thrombocytopenia can cause individuals to bruise easily or have episodes of prolonged bleeding following minor trauma or even in the absence of injury (spontaneous bleeding). Some people with this condition experience spontaneous bleeding in the brain (cerebral hemorrhage), which can cause brain damage that can be life-threatening.","mondoId":"MONDO:0010743","records":[{"frequencyKind":"reported","key":"187674234136531057e0778ed66b46665abfec7147546dab60e0cd0ce052f641","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000978","is_excluded":false,"label":"Bruising susceptibility","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"1bcf052ebfd3890e605b23fb41ea941e5e7155d76bf674c3bce659c2d38c6dd0","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000967","is_excluded":false,"label":"Petechiae","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"224944c9d58f8dd52a5c87bbf8c3e9984c29d1264c9a8a4a59d75c2722936a1c","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0005261","is_excluded":false,"label":"Joint hemorrhage","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"61393d1a4d9343998248b9a463098fdef603d9149f0ba2cd8b2ac23f8da4cf29","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000421","is_excluded":false,"label":"Epistaxis","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"70ed20b439f9f0b1b15d502cdbc07a6236eac8e5afc209f16a5044d3c5ef7cb8","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003261","is_excluded":false,"label":"Increased circulating IgA concentration","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"73748baa3588f32742959cbcde0e9ea5945bcd5d8aaa815b17dbead59e148240","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003212","is_excluded":false,"label":"Increased circulating IgE concentration","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"77d0818f6f1f4777bc8211500277986912c6ed7c90ac2fddd9cbc7dce7aa51e4","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0004854","is_excluded":false,"label":"Intermittent thrombocytopenia","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"reported","key":"8405e8a497d2822edbd9b2564995e2c255f56c4bb77ed68858ebe7e166caae9e","raw":{"aspect":"P","body_system":"skin","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0000964","is_excluded":false,"label":"Eczematoid dermatitis","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]},{"frequencyKind":"count","key":"8467e4494f5443ef634a8cd6c20822d8ec1e81983f07f8684a768105a0052215","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"PCS","frequency_raw":"3/3","hpo_id":"HP:0001905","is_excluded":false,"label":"Congenital thrombocytopenia","onset_id":null,"reference":"PMID:7795648","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"d4259bd1bccd29611ae19d4f02f219dbe76539ec33411c43dac7a4fda37cf3d1","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"PCS","frequency_raw":"3/3","hpo_id":"HP:0005537","is_excluded":false,"label":"Decreased mean platelet volume","onset_id":null,"reference":"PMID:7795648","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"f93a1bed729c7e3bca780797e4b8a0462ae1712b1b83a0cdc84d1e4a4456a099","raw":{"aspect":"P","body_system":"musculoskeletal","disease_id":"OMIM:313900","disease_name":"Thrombocytopenia 1","evidence":"IEA","frequency_raw":null,"hpo_id":"HP:0003011","is_excluded":false,"label":"Abnormality of the musculature","onset_id":null,"reference":"OMIM:313900","source_release":"2026-06-23"},"sourceGroups":["omim"]}],"referenceLabels":{},"references":{"causeHtml":"","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"Mutations in the WAS gene cause X-linked thrombocytopenia. The WAS gene provides instructions for making a protein called WASP. This protein is found in all blood cells. WASP is involved in relaying signals from the surface of blood cells to the actin cytoskeleton, which is a network of fibers that make up the cell's structural framework. WASP signaling activates the cell when it is needed and triggers its movement and attachment to other cells and tissues (adhesion). In white blood cells, which protect the body from infection, this signaling allows the actin cytoskeleton to establish the interaction between cells and the foreign invaders that they target (immune synapse).
WAS gene mutations that cause X-linked thrombocytopenia typically lead to the production of an altered protein. The altered WASP has reduced function and cannot efficiently relay signals from the cell membrane to the actin cytoskeleton. In people with X-linked thrombocytopenia, these signaling problems primarily affect platelets, impairing their development. In some cases, white blood cells are affected. When WASP function is impaired in white blood cells, they are less able to respond to foreign invaders and immune problems such as infections, eczema, and autoimmune disorders can occur.
","key":"forms","title":"What causes X-linked thrombocytopenia?"},{"bodyHtml":"Some people with X-linked thrombocytopenia also have patches of red, irritated skin (eczema) or an increased susceptibility to infections. In severe cases, additional features can develop, such as cancer or autoimmune disorders, which occur when the immune system malfunctions and attacks the body's own tissues and organs. It is unclear, however, if people with these features have X-linked thrombocytopenia or a more severe disorder with similar signs and symptoms called Wiskott-Aldrich syndrome.
Some people have a mild form of the disorder called intermittent thrombocytopenia. These individuals have normal platelet production at times with episodes of thrombocytopenia.
Source: MedlinePlus Genetics
","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"x-linked-thrombocytopenia","sourceDocuments":[{"name":"X-linked thrombocytopenia","reviewed":"2013-02","sections":{"causes":{"fetchedAt":"2026-10-20T20:26:01.273972+00:00","label":"Causes","pageSha256":"d40691e30ae1075a179760e7bd598b31f6d1ed63477dacc1f475eb3fed31d70c","sourceUrl":"https://medlineplus.gov/genetics/condition/x-linked-thrombocytopenia/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/x-linked-thrombocytopenia"}],"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":"X-linked thrombocytopenia"},"schemaVersion":1}