Polydactyly of a biphalangeal thumb…

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Polydactyly of a biphalangeal thumb and/or hallux

ORPHA:93339Morphological anomaly

Also called PPD1 · Preaxial polydactyly type 1

What it is

A rare non-syndromic limb malformation characterized by the duplication of one or more skeletal components of a biphalangeal thumb and/or hallux. Hands are preferentially affected (in bilateral), and the right hand is more commonly involved than the left. Hallux duplication may present concomitantly to, or independently of thumb polydactyly and is predominantly unilateral right.

Key facts

Age of onset
Infancy, Neonatal
Inheritance
Autosomal dominant
Classified as
Morphological anomaly

Gene

GLI1Disease-causing germline mutation(s)

ICD-10 codes

Q69.1ICD-10 names this disease exactly — shared with 1 other rare disease

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

MESH C536332OMIM 174400UMLS C1395852

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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