polydactyly of a biphalangeal thumb
Findings
No curated finding names polydactyly of a biphalangeal thumb yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Polydactyly of a biphalangeal thumb or PPD1 is the most common form of preaxial polydactyly of fingers, a limb malformation syndrome, that is characterized by the duplication of one or more skeletal components of a biphalangeal thumb. Hands are preferentially affected (in bilateral), and the right hand is more commonly involved than the left.
Definition from the Mondo Disease Ontology (MONDO:0008269), read 2026-09-29. CC BY 4.0.
Genes
1 gene
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.
- GLI1HGNC:4317
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
- Limited · Ambry Genetics · Autosomal recessive · 2019
Where it sits
Other names
3 names
Resolves to: polydactyly of a biphalangeal thumb
- Also called
- polydactyly, preaxial type 1PPD1preaxial polydactyly type 1