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":0,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":6,"sourceGroups":{"omim":0,"orphanet":0,"published":6}},"features":[{"hpoId":"HP:0031699","label":"Disseminated cryptosporidium infection","primary":false},{"hpoId":"HP:0001508","label":"Failure to thrive","primary":false},{"hpoId":"HP:0005353","label":"Recurrent herpes","primary":false},{"hpoId":"HP:0002742","label":"Recurrent Klebsiella infection","primary":false},{"hpoId":"HP:0005381","label":"Recurrent Neisseria meningitidis infection","primary":false},{"hpoId":"HP:0001581","label":"Recurrent skin infections","primary":false}],"ledeHtml":"Mannose-binding lectin deficiency is a condition that affects the immune system. People with this condition have low levels (deficiency) of an immune system protein called mannose-binding lectin in their blood. Whether this deficiency makes affected individuals prone to recurrent infections is not clear.","mondoId":"MONDO:0013714","records":[{"frequencyKind":"reported","key":"472ee743c4f27a4bf12d9b820dc0c416a9705a8356034e3b9c099bdcdf44f4d3","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0005381","is_excluded":false,"label":"Recurrent Neisseria meningitidis infection","onset_id":null,"reference":"PMID:7707811","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"7a3bf7cfe08973118c329cd31dba670279b5d71b7ac5d74f941944e28cb74553","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0001581","is_excluded":false,"label":"Recurrent skin infections","onset_id":null,"reference":"PMID:7707811","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"a8f9a9af26bba64382f07209b426cf21d3d3a282a38a185904eee790919fc01a","raw":{"aspect":"P","body_system":"growth","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0001508","is_excluded":false,"label":"Failure to thrive","onset_id":null,"reference":"PMID:769701","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"db0ed384e1f9cba6e16fb16a24d262cdfea81d698bbd52212001432bc78e4e15","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0031699","is_excluded":false,"label":"Disseminated cryptosporidium infection","onset_id":null,"reference":"PMID:7707811","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"e4109fdc6c1c08c4c69d05b7e8c2a214960ca58b3e5b20e2a5839b33e7c76ed9","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0005353","is_excluded":false,"label":"Recurrent herpes","onset_id":null,"reference":"PMID:7707811","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"e767a19b8e5e18d2175d470fe6f171a3034cd7f7fa9b4ca89faa08dba6f94e7c","raw":{"aspect":"P","body_system":"immune","disease_id":"OMIM:614372","disease_name":"Mannose-Binding lectin deficiency","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0002742","is_excluded":false,"label":"Recurrent Klebsiella infection","onset_id":null,"reference":"PMID:7707811","source_release":"2026-06-23"},"sourceGroups":["published"]}],"referenceLabels":{},"references":{"causeHtml":"","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"Relatively common mutations in the MBL2 gene can lead to mannose-binding lectin deficiency. This gene provides instructions for making a protein that assembles into a complex called mannose-binding lectin. Functional mannose-binding lectins are made up of two to six protein groups called trimers, which are each composed of three of the protein pieces (subunits) produced from the MBL2 gene.
Mannose-binding lectin plays an important role in the body's immune response by attaching to foreign invaders such as bacteria, viruses, or yeast and turning on (activating) the complement system. The complement system is a group of immune system proteins that work together to destroy foreign invaders (pathogens), trigger inflammation, and remove debris from cells and tissues. Mannose-binding lectin can also stimulate special immune cells to engulf and break down the attached pathogen.
Mutations in the MBL2 gene can reduce the production of the mannose-binding lectin subunit or eliminate the subunit's ability to assemble into functional mannose-binding lectin. A decrease in the availability of the normal subunit protein may lead to a reduction of the functional mannose-binding lectin in blood. With decreased levels of mannose-binding lectin, the body does not recognize and fight foreign invaders efficiently. Consequently, infections can be more common in people with this condition.
However, not everyone with a change in the MBL2 gene has decreased levels of mannose-binding lectin, and not everyone with decreased protein levels is prone to infection. Researchers believe that a number of factors, including other genetic and environmental factors, are involved in the development of mannose-binding lectin deficiency and susceptibility to infection.
","key":"forms","title":"What causes Mannose-binding lectin deficiency?"},{"bodyHtml":"People with mannose-binding lectin deficiency can develop infections of the upper respiratory tract and other body systems. Individuals with this condition may also contract more serious infections such as pneumonia and meningitis. Depending on the type of infection, the symptoms caused by the infections vary in frequency and severity.
Infants and young children with mannose-binding lectin deficiency seem to be more susceptible to infections than affected adults, but adults can also develop recurrent infections. In addition, affected individuals undergoing chemotherapy or taking drugs that suppress the immune system are especially prone to infections.
Source: MedlinePlus Genetics
","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"mannose-binding-lectin-deficiency","sourceDocuments":[{"name":"Mannose-binding lectin deficiency","reviewed":"2012-03","sections":{"causes":{"fetchedAt":"2026-10-20T20:23:06.047849+00:00","label":"Causes","pageSha256":"37f999c8ac8a32c559b39d5d76a4fed1c56360050bad0138075b506acd6d0dc2","sourceUrl":"https://medlineplus.gov/genetics/condition/mannose-binding-lectin-deficiency/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/mannose-binding-lectin-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":"Mannose-binding lectin deficiency"},"schemaVersion":1}