Where Does Syndactyly Occur?

While any two or more fingers can be joined, syndactyly most often occurs between the middle and ring fingers. The fingers may be connected by a flap of skin that looks like webbing. In other cases, the fused digits may look almost like a single finger. Syndactyly is fairly common.

Where does syndactyly come from?

What causes syndactyly? During pregnancy, a baby's hands form in the shape of a paddle and later split into separate fingers. This happens very early, around the sixth to eighth week of pregnancy. Syndactyly happens if two or more fingers do not separate during this time.

What causes webbed digits?

Webbing of the digits, or syndactyly, is not caused by the fingers sticking together in the womb; rather, it is caused by failure, during the sixth to eighth weeks of intrauterine life, of the usual longitudinal interdigital necrosis that normally separates the fingers.