mesoaxial synostotic syndactyly with phalangeal reduction
Findings
No curated finding names mesoaxial synostotic syndactyly with phalangeal reduction yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Mesoaxial synostotic syndactyly (MSSD) with phalangeal reduction is a novel and distinct form of non-syndromic syndactyly including complete syndactyly of the 3rd and 4th fingers with synostoses of the corresponding metacarpals and associated single phalanges, syndactyly of the 2nd and 3rd toes and 5th finger clinodactyly.
Definition from the Mondo Disease Ontology (MONDO:0012271), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Congenital onset
HPO, annotations 2026-09-02
Features
13 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.
- 2-3 toe syndactylyHPOHP:0004691
- Very frequent (80% to 99% of cases)
- Aplasia/Hypoplasia of the halluxHPOHP:0008362
- Very frequent (80% to 99% of cases)
- Aplasia/Hypoplasia of the middle phalanges of the handHPOHP:0009843
- Very frequent (80% to 99% of cases)
- Clinodactyly of the 5th fingerHPOHP:0004209
- Very frequent (80% to 99% of cases)
- Finger symphalangismHPOHP:0009700
- Very frequent (80% to 99% of cases)
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.
- BHLHA9HGNC:35126
- Definitive · G2P · Autosomal recessive · 2015
- Strong · Ambry Genetics · Autosomal recessive · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
3 names
Resolves to: mesoaxial synostotic syndactyly with phalangeal reduction
- Also called
- MSSDsyndactyly type 9syndactyly, Malik-Percin type