Saethre Chotzen Syndrome (SCS)

What is Saethre Chotzen syndrome (SCS)?

Saethre Chotzen syndrome (SCS) belongs to a group of rare genetic disorders known as “acrocephalosyndactyly” disorders, which are all characterized by premature closure of the fibrous joints between skull bones and/or webbing or fusion of fingers or toes. This results in SCS patients having craniofacial asymmetry, as bones in the skull cannot grow normally.

What causes Saethre Chotzen syndrome (SCS)?

In most cases, SCS is caused by mutations in the TWIST1 gene, which are inherited in an autosomal dominant fashion. However, in some individuals, SCS is caused by a spontaneous genetic mutation and not inherited from either parent.

What are the symptoms of Saethre Chotzen syndrome (SCS)?

SCS is primarily characterized by craniosynostosis, distinctive facial variations, and variations of the fingers and toes. However, these symptoms may be extremely variable, even among affected members of the same family. For example, when craniosynostosis is present, the degree of skull malformation is variable, depending on the specific cranial sutures involved and the order and rate of progression. The head may appear pointed, unusually short or broad, or triangularly shaped. Depending on the shape, SCS may lead to abnormally increased pressure within the skull or intellectual disability Craniofacial variations of SCS can result in the following:

• Broad forehead with a low hairline
• Drooping of upper eyelids
• A “beaked” nose
• Depressed nasal bridge
• Small upper jaw and/or protrusion of the lower jaw
• Widely spaced eyes or shallow eye cavities
• Highly arched roof of the mouth and dental defects

How is Saethre Chotzen syndrome (SCS) diagnosed?

SCS is diagnosed based mainly on the presence of characteristic clinical findings, seen through a CT scan of the head or radiographs of skull, spine, and limb abnormalities. Genetic testing to determine a mutation or deletion in the TWIST1 gene can confirm a SCS diagnosis.

What are the available treatments for Saethre Chotzen syndrome (SCS)?

Surgery for SCS is usually advised in the first year of life to help prevent or correct early closure of cranial sutures, to prevent any pressure that may occur, and to prevent any progressive facial asymmetry. Other treatments for SCS are symptomatic and supportive, such as eye care for vision abnormalities or special education for intellectual disability.

Where can I find more information about Saethre Chotzen syndrome (SCS)?

• National Organization for Rare Disorders (NORD)
• Orphanet
• NIH