polydactyly of a triphalangeal thumb
Findings
No curated finding names polydactyly of a triphalangeal thumb yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A form of preaxial polydactyly of fingers, a limb malformation syndrome, that is characterized by the presence of a usually opposable triphalangeal thumb with or without additional duplication of one or more skeletal components of the thumb. The thumb appearance can differ widely in shape (wedge to rectangular) or it can be deviated in the radio-ulnar plane (clinodactyly). PPD2 is also associated with systemic syndromes, including Holt-Oram syndrome and Fanconi anemia.
Definition from the Mondo Disease Ontology (MONDO:0008270), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
HPO, annotations 2026-09-02
Features
5 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Preaxial hand polydactylyHPOHP:0001177
- Very frequent (80% to 99% of cases)
- Postaxial foot polydactylyHPOHP:0001830
- Frequent (30% to 79% of cases)
- Postaxial hand polydactylyHPOHP:0001162
- Frequent (30% to 79% of cases)
- Preaxial foot polydactylyHPOHP:0001841
- Frequent (30% to 79% of cases)
- SyndactylyHPOHP:0001159
- Frequent (30% to 79% of cases)
Genes
2 genes
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
Where it sits
- A kind of
Other names
5 names
Resolves to: polydactyly of a triphalangeal thumb
- Also called
- polydactyly, preaxial type 2polydactyly, preaxial type IIPPD2preaxial polydactyly type 2triphalangeal thumb, type i