Syndactyly type 2

Syndactyly Type 2

Syndactyly Type 2, also known as synpolydactyly, is a rare congenital malformation characterized by the fusion of fingers or toes (syndactyly) accompanied by the presence of extra digits (polydactyly). This condition is part of a group of disorders known as limb malformations.

Etiology

Syndactyly Type 2 is primarily caused by genetic mutations. The most common genetic cause is mutations in the HOXD13 gene, which plays a crucial role in limb development. This gene is located on chromosome 2q31 and is part of the homeobox gene family that regulates the pattern of anatomical development.

Clinical Features

Individuals with Syndactyly Type 2 typically present with:

• Fusion of the third and fourth fingers or toes.
• Presence of an extra digit, often between the fused digits.
• Variable expression, meaning the severity and specific presentation can differ among individuals.

Diagnosis

Diagnosis of Syndactyly Type 2 is based on:

• Clinical examination to assess the extent of digit fusion and presence of extra digits.
• Genetic testing to identify mutations in the HOXD13 gene.
• Radiographic imaging to evaluate the bone structure and confirm the diagnosis.

Treatment

Treatment options for Syndactyly Type 2 may include:

• Surgical separation of fused digits to improve function and appearance.
• Removal of extra digits if they interfere with hand or foot function.
• Physical therapy to enhance mobility and dexterity post-surgery.

Prognosis

The prognosis for individuals with Syndactyly Type 2 is generally good, especially with early intervention. Surgical treatment can significantly improve hand and foot function, although some residual deformity may persist.

Genetic Counseling

Genetic counseling is recommended for families affected by Syndactyly Type 2. Since the condition is inherited in an autosomal dominant manner, there is a 50% chance of passing the mutation to offspring.

Research and Future Directions

Ongoing research aims to better understand the genetic mechanisms underlying Syndactyly Type 2 and to develop improved surgical techniques and therapeutic interventions.

NIH genetic and rare disease info

• NIH info on Syndactyly type 2

Syndactyly type 2 is a rare disease.