Rare diseases · Sign or symptom
Postaxial polydactyly
HP:0100259
What it means
A form of polydactyly in which the extra digit or digits are localized on the side of the fifth finger or fifth toe.
Rare diseases that can present with this10
Common30–79%
2Sometimes5–29%
7- Houge-Janssens syndrome type 2
- Joubert syndrome with Jeune asphyxiating thoracic dystrophy
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to 9q21.3 microdeletion
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to a point mutation
- Proximal 3p25.3 microdeletion syndrome
- Pseudoaminopterin syndrome
- SYNGAP1-related developmental and epileptic encephalopathy
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: Polydactyly, postaxial · Postaxial hexadactyly
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
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.