228050004

SNOMED CT concept 228050004 is "21q partial trisomy" (FSN: 21q partial trisomy (disorder)). It sits in the disorder semantic tag.

21q partial trisomy maps to ICD-10 code: Q90.9.

21q partial trisomy is grouped under UMLS CUI C0265486. UMLS CUIs let you bridge between SNOMED CT and other terminologies (ICD-10, ICD-11, LOINC, RxNorm).

21q partial trisomy is in the SNOMED CT "disorder" semantic tag. Semantic tags partition the terminology by what kind of clinical idea each concept represents (finding, disorder, procedure, body structure, substance, and so on).

SNOMED CT is the world's most comprehensive clinical terminology, with around 350,000 active concepts covering diseases, findings, procedures, body structures, and substances. It is the recommended terminology for EHR problem lists in many countries.

SNOMED CT describes clinical meaning. ICD-10 (and ICD-10-CM) describes billing categories. The SNOMED to ICD-10-CM map (maintained by NLM) gives one or more ICD codes per SNOMED concept. We expose those mappings on each concept page and through the cross_references field on the API.

Browsing the directory is free for anyone with a browser. Programmatic access (the /v1/reference/snomed-ct/* endpoints) needs an API key. Free tier covers low-volume hobby use; paid tiers cover production traffic.

Either type the ID or a term into the search bar above, or call GET /v1/reference/snomed-ct/{concept_id}. Both paths return the same data: FSN, preferred term, semantic tag, synonyms, and cross-maps to ICD-10, ICD-11, UMLS, LOINC, and RxNorm where they exist.

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