brachydactyly type A1
Findings
No curated finding names brachydactyly type A1 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare, congenital limb malformation characterized by shortened or underdeveloped middle phalanges of all digits, that are sometimes fused with the terminal phalanges. The proximal phalanges of the thumbs and big toes are also shortened. Short stature in adulthood has been reported in association.
Definition from the Mondo Disease Ontology (MONDO:0007215), read 2026-09-29. CC BY 4.0.
Features
18 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.
- Short footHPOHP:0001773
- Very frequent (80% to 99% of cases)
- Short halluxHPOHP:0010109
- Very frequent (80% to 99% of cases)
- Short middle phalanx of fingerHPOHP:0005819
- Very frequent (80% to 99% of cases)
- Short statureHPOHP:0004322
- Very frequent (80% to 99% of cases)
- Short thumbHPOHP:0009778
- Very frequent (80% to 99% of cases)
- Cone-shaped epiphysisHPOHP:0010579
- Frequent (30% to 79% of cases)
- Broad metacarpalsHPOHP:0001230
- Occasional (5% to 29% of cases)
- Clinodactyly of the 5th fingerHPOHP:0004209
- Occasional (5% to 29% of cases)
- Distal finger symphalangismHPOHP:0001204
- Occasional (5% to 29% of cases)
- Hypoplasia of the ulnaHPOHP:0003022
- Occasional (5% to 29% of cases)
- ScoliosisHPOHP:0002650
- Occasional (5% to 29% of cases)
- Talipes equinovarusHPOHP:0001762
- Occasional (5% to 29% of cases)
Show the remaining 6
- Aplasia/Hypoplasia of the middle phalanges of the handHPOHP:0009843
- Aplasia/Hypoplasia of the middle phalanges of the toesHPOHP:0010194
- Flattened metatarsal headsHPOHP:0005194
- Short metacarpalHPOHP:0010049
- Short proximal phalanx of halluxHPOHP:0010107
- Short proximal phalanx of thumbHPOHP:0009638
Genes
3 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.
- IHHHGNC:5956
- Definitive · Ambry Genetics · Autosomal dominant · 2024
- Definitive · G2P · Autosomal dominant · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2021
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
- BMPR1BHGNC:1077
- Supportive · Orphanet · Autosomal dominant · 2021
- GDF5HGNC:4220
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
2 names
Resolves to: brachydactyly type A1
- Also called
- BDA1brachydactyly, Farabee type