Rare diseases · Sign or symptom
1-2 finger cutaneous syndactyly
Webbed 1st-2nd finger
HP:0010704
What it means
A soft tissue continuity in the anteroposterior axis between the thumb to the index finger that extends distally to at least the level of the proximal interphalangeal joints.
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: Webbed thumb and index finger
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.