brachydactyly type B
Findings
No curated finding names brachydactyly type B yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A condition characterized by incomplete development (hypoplasia) or absence of the outermost bones of the fingers and toes (distal phalanges) and nails. Additional features may include hypoplasia of the middle phalanges, fusion of the joints (symphalangism), broad thumbs, and webbed fingers (syndactyly). The feet are often less severely affected than the hands. There are 2 types of this condition, designated as type 1 and 2. BDB type 1 is caused by mutations in the ROR2 gene. BDB type 2 is caused by mutations in the NOG gene. Inheritance of both types is autosomal dominant. Treatment may include surgery if the condition affects hand function, or for cosmetic reasons.
Definition from the Mondo Disease Ontology (MONDO:0019676), read 2026-09-29. CC BY 4.0.
Features
10 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.
- 2nd-5th toe middle phalangeal hypoplasiaHPOHP:0008083
- Very frequent (80% to 99% of cases)
- Absent fingernailHPOHP:0001817
- Very frequent (80% to 99% of cases)
- Short distal phalanx of fingerHPOHP:0009882
- Very frequent (80% to 99% of cases)
- Short footHPOHP:0001773
- Very frequent (80% to 99% of cases)
- Short metacarpalHPOHP:0010049
- Very frequent (80% to 99% of cases)
- Type B brachydactylyHPOHP:0005831
- Very frequent (80% to 99% of cases)
Where it sits
- A kind of
- Narrower terms (2)