Syndactyly is the congenital fusion of soft tissue and/or osseous structures between two fingers. It can be present as an isolated anomaly or in association with polydactlyly, acrosyndactyly, clinodactyly, synostosis, or cleft hand. It can also be a feature in numerous congenital syndromes, including Apert’s syndrome, Poland’s syndrome, Pfeiffer syndrome, and Holt-Oram syndrome. Syndactyly and polydactyly (the presence of extraneous digits) represent the two most common congenital limb abnormalities.

The incidence is approximately 1 per 2500 to 5000 live births. It can be corrected surgically in almost all cases.

Bilateral syndactyly and syndactyly of the 3rd and 4th digits are both exceedingly rare. They are usually seen in association with complex disorders (e.g., Apert's syndrome, triploidy). Our patient has non-syndromic syndactyly, a sporadic occurrence without any associated anomalies.