Syndactyly describes a condition in which two or more fingers or toes are joined together.
When two or more fingers or toes are webbed together, a child has a condition called syndactyly. It can occur sporadically or may be linked to one of about 300 diseases.
Polysyndactyly is a similar condition that refers to webbing plus the presence of extra fingers or toes.
Depending on the fingers or toes that are webbed, there are several types of syndactyly, including:
Simple – soft tissue joins fingers or toes
Complex – bone and tissue join fingers or toes
Complete – entire finger is fused
Incomplete – fingers are joined partially
Complicated – fingers or toes are joined in a manner that is not side-by-side
When a baby develops in the womb, fingers and toes are webbed together, but then separate around the sixth to eighth week of development. Sometimes, the fingers and toes do not separate. Some cases are sporadic, while a genetic abnormality can cause others.
As many as 300 different conditions, including Down syndrome, have syndactyly as a symptom.