HPO to SNOMED mapping - the objectives
The objectives was to produce a mapping with a fully logically defined product so that if a direct map to a SNOMED concept was not available, an expression was constructed using Compositional Grammar and post-coordination.
Expressions, Post-coordination resources
These expressions have been authored using the following resources and validated against the April 2024 Release of SNOMED International;
- Machine Readable Concept Model-https://browser.ihtsdotools.org/mrcm/?branch=MAIN%2F2020-07-31
- Postco-ordination demonstrator - expression validation (classification) -Postcoordination Implementation Demo (ihtsdo.github.io)
- Practical Guide to Post-coordination -https://snomed.org/postcoordination
- SNOMED International browser
HPO to SNOMED Cross Mapping - the results
Based on the HPO release of August 2024, and the SNOMED International release of April 2024, the mapping results are given below.
Note that 86% of the HPO terms are mappable either directly or involving an expression, so that the missing 13% could potentially be reduced with new SNOMED content.
The expressions have been validated using the Post-coordination Demonstrator resource. (Postcoordination Implementation Demo (ihtsdo.github.io))
| Group | Number (%) |
|---|---|
| One to one map | 7184 (41%) |
| One to many | 81 (0.5%) |
| Map with expression | 7833 (45%) |
| Map to parent | 2338 (13.4%) |
| Clarification | 22 (0.1%) |
| Out of scope | 685 (3.9) |
| Total | 18,370 |
Examples of post-coordination
HPO concept | SNOMED post-coordinated expression | ||
1 | HP:0001525 Severe failure to thrive | 54840006 |Failure to thrive (disorder)|: {246112005 |Severity (attribute)|=24484000 |Severe (severity modifier) (qualifier value)|} | approx (45%) |
2 | HP:0004363 Abnormal circulating calcium concentration. | 1217344005 |Finding of blood substance level (finding)|: {363713009 |Has interpretation (attribute)| =394844007 |Outside reference range (qualifier value)|, 363714003 |Interprets (attribute)| =312472004 |Blood calcium measurement (procedure)|} | approx 30% |
3 | HP:6000554 Positive bloodstream plasmodium falciparum nucleic acid pathogen test. | 434156008 |Infectious agent in bloodstream (finding)|: {363713009 |Has interpretation (attribute)| = 10828004 |Positive (qualifier value)|, 363714003 |Interprets (attribute)| = (398545005 |Nucleic acid assay (procedure)|: 246093002 |Component (attribute)| =708396002 |Deoxyribonucleic acid of Plasmodium falciparum (substance)|, 370129005 |Measurement method (attribute)|=444077007 |Analysis using reverse transcriptase polymerase chain reaction technique (procedure)|)} | 637 (8%) |