Leonardo's Hands Fequently Asked Questions.  Here you will find answers and definitions to questions and terms related to the study of Leonardo's Hands.

What is Ectrodactyly?

Ectrodactyly is the congenital absence of all or part of one or more fingers or toes. This term is used for a range of conditions from aphalangia (in which the some of the phalanges or finger bones are missing), to adactyly (the absence of a digit).

A fusing of almost all digits on all of the hands and feet is ectrodactyly. News anchor Bree Walker is probably the best-known person with this condition, which affects about one in 91,000 people. It is conspicuously more common in the Vadoma in Zimbabwe.

What is Syndactyly?

Syndactyly is a condition where two or more digits are fused together. It occurs normally in some mammals, such as the siamang. It occurs as an unusual condition in humans.

Syndactyly can be simple or complex. In simple syndactyly, adjacent fingers or toes are joined by soft tissue. In complex syndactyly, the bones of adjacent digits are fused. The kangaroo exhibits complex syndactyly.

Simple syndactyly can be full or partial, and is present at birth (congenital). In early human fetal development, webbing (syndactyly) of the toes and fingers is normal. At about 16 weeks of gestation, apoptosis takes place and an enzyme dissolves the tissue between the fingers and toes, and the webbing disappears. In some fetuses, this process does not occur completely between all fingers or toes and some residual webbing remains. The exact cause is not known. In cases, this condition appears to be hereditary.

In the case of human feet, syndactyly does not affect the function of the foot or toes and does not interfere with walking or swimming or any other activities. Although webbing of the fingers usually does not affect the function of the hand, it can impair function of the fingers. Surgery may be performed to separate webbed fingers or toes. As with any surgery, there are risks of complications. This procedure involves local anesthesia with a sedative and can be done just with a local without the sedative for adults if desired. In addition to the incision between the toes, sometimes it is necessary to remove some skin from elsewhere on the body to graft into the newly exposed space between the toes.

In the case of webbed toes, surgical separation is a purely cosmetic operation with no medical benefits.