Rare diseases · Sign or symptom
Mesoaxial hand polydactyly
HP:0006159
What it means
The presence of a supernumerary finger (not a thumb) involving the third or fourth metacarpal with associated osseous syndactyly.
Rare diseases that can present with this1
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: Central hand polydactyly · Interdigital finger polydactyly
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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.