Rare diseases · Sign or symptom
Aplasia/Hypoplasia of the patella
Absent/small kneecap
HP:0006498
What it means
Absence or underdevelopment of the patella.
Rare diseases that can present with this7
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Absent or hypoplastic patellae · Absent/hypoplastic patella · Absent/underdeveloped kneecap · Aplastic or hypoplastic patellae · Hypoplastic or absent patella · Patellar aplasia/hypoplasia · Small to absent patellae
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.