syndactyly

Epidemiology

More common in African Americans

Aetiology

Sporadic and AD

VACTERL

Classification

Preaxial

Type 1:  Thumb polydactyly

Type 2:  Triphalangeal thumb

Type 3:  Index polydactyly

Type 4:  Polysyndactyly

Central

Classification

Pre-axial / great toe / 15%

Central / 2-4 MT / 5%

Post-axial / 5th MT / 80%

Type A - articulated

Type B - rudimentary 

Epidemiology

2 in 1000 births

- 30% positive FHx

- autosomal dominant

Associated MT anomalies common

- block MT / Y-shaped / T-shaped /wide head

Treatment