Prevalence: 3 to 10 /10,000 births. Malformation of fingers and/or toes that are totally or partly fused (due, for example, to a disorder of physiological apoptosis of the interdigital skin) during the formation of the extremities. The toes are more frequently affected than fingers, and  boys twice more often than girls. There are  so-called syndromic forms (associated with a syndrome such as Apert syndrome, for example) or isolated. Several classifications have been described.

The simplest is one that describes the following forms:

-        preaxial: when the radial ray (or the side of the big toe) is affected

-        mesoaxial: when the middle part of the extremity is involved

-        postaxial: when the ulnar ray (or the side of the little toe) is involved

-        and total

A fuller and more complex of isolated syndactylies classification is that of Temtamy-McKusick recently extended and adapted to the new data of molecular genetics (see figures).

SPD = synpolydactyly = association of syndactyly and a polydactyly

AD = autosomal dominant, AR = autosomale recessive, X = X-linked

NL = normal  SPD = SynPolyDactyly

Anesthetic implications:

check for associated anomalies, anticipate difficult peripheral venous access .

References :  

-        Malik S. 
Syndactyly : phenotypes, genetics and current classification. 
Eur J Human Genet 2012 ; 20 : 817-24

Updated: June 2015