Syndactyly type 1

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Syndactyly type 1

ORPHA:93402Morphological anomaly

What it is

A rare non-syndromic syndactyly characterized by complete or partial webbing between the 3rd and 4th fingers and/or the 2nd and 3rd toes. Other digits may be involved occasionally. The phenotype varies widely within and between families, sometimes only the hands are affected and sometimes only the feet. Webbing between fingers may be associated with bony fusion of the distal phalanges.

Key facts

Prevalence
1-5 / 10 000 (Europe)
Age of onset
Antenatal, Infancy, Neonatal
Inheritance
Autosomal dominant
Classified as
Morphological anomaly

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

Sometimes5–29%

1
  • Symphalangism affecting the phalanges of the hand

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

Genes reported in subtypes

HOXD13

Orphanet records this gene on 1 more specific entry under this disorder, not on this entry itself:

A well-studied disease is usually split into subtypes, and the gene is curated on whichever one the evidence belongs to. Open a subtype to see which gene goes with it.

ICD-10 codes

Q70.1ICD-10 uses a narrower term — shared with 4 other rare diseases
Q70.3ICD-10 uses a narrower term — shared with 4 other rare diseases

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Cross-references

GARD 5081MESH C566096MONDO 0008512OMIM 185900UMLS C1861380

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

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