Syndactyly may be discovered during an examination of an infant or child. In its most common form, it is seen as webbing between the 2nd and 3rd toes. This form is often inherited and is not unusual. Syndactyly can also occur along with other birth defects involving the skull, face, and bones.

The web connections usually run up to�the first joint of the finger or toe, but may run the�entire length.

"Polysyndactyly" describes both webbing and the presence of an extra number of fingers or toes.

Relatively common causes:

• Hereditary syndactyly
• Down syndrome

Extremely rare causes:

• Apert's syndrome
• Fetal hydantoin effect (mother took hydantoin during pregnancy)
• Carpenter's syndrome
• Smith-Lemli-Opitz syndrome
• Pfeiffer syndrome
• Cornelia de Lange syndrome

This condition is normally discovered at birth and evaluated during the newborn hospital stay.

The health care provider will perform a physical exam and ask questions about the patient's medical history. Questions may include:

Medical history questions may include:

• Which fingers (toes) are involved?
• Have any other family members had this problem?
• What other symptoms or abnormalities are also present?

An infant with webbing may have other symptoms and signs that, when taken together, define a specific syndrome or condition. Diagnosis of that condition is based on a family history, medical history, and�a physical exam.

The following tests may be done:

• Chromosome studies �
• Enzyme assays
• X-rays
• Metabolic studies