sirenomelia
Findings
No curated finding names sirenomelia yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Sirenomelia is a rare, genetic, developmental defect during embryogenesis disorder characterized by fusion of the lower limbs and associated with some degree of lower extremity reduction and persistent vitelline artery. Patients also present severe malformations of the musculoskeletal system (e.g. sacral agenesis), as well as the urogenital and lower gastrointestinal tracts (e.g. renal agenesis, absent bladder, rectal/anal atresia, and absent internal genitalia). Most cases are stillborn, or die during, or shortly after, birth.
Definition from the Mondo Disease Ontology (MONDO:0017850), read 2026-09-29. CC BY 4.0.
Features
10 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Abnormality of the urinary systemHPOHP:0000079
- Very frequent (80% to 99% of cases)
- Absence of the sacrumHPOHP:0010305
- Very frequent (80% to 99% of cases)
- Ambiguous genitaliaHPOHP:0000062
- Very frequent (80% to 99% of cases)
- Anal atresiaHPOHP:0002023
- Very frequent (80% to 99% of cases)
- Renal hypoplasia/aplasiaHPOHP:0008678
- Very frequent (80% to 99% of cases)
- SirenomeliaHPOHP:0010497
- Very frequent (80% to 99% of cases)
Where it sits
- A kind of
Other names
1 name
Resolves to: sirenomelia
- Also called
- symmelia