Saethre-Chotzen syndrome

Saethre-Chotzen syndrome (also known as acrocephalosyndactyly type III or ACS III) is a genetic disorder primarily characterized by premature fusion of certain skull bones (craniosynostosis), which affects the shape of the head and face. It is caused by mutations in the TWIST1 gene on chromosome 7p21.1, which encodes a basic helix-loop-helix transcription factor critical for normal craniofacial and limb development. In some cases, larger deletions encompassing the TWIST1 gene region may occur, which can be associated with a more severe phenotype including intellectual disability. The hallmark features of Saethre-Chotzen syndrome include coronal craniosynostosis (which may be unilateral or bilateral), resulting in a short and broad head (brachycephaly) or an asymmetric skull (plagiocephaly). Characteristic facial features include a low frontal hairline, facial asymmetry, ptosis (drooping eyelids), hypertelorism or telecanthus, a beaked nose, and small, low-set ears with prominent crus helicis. Limb abnormalities are common and typically include cutaneous syndactyly (soft tissue webbing) of the second and third fingers and/or toes, brachydactyly (short fingers), and broad great toes. Mild to moderate short stature may be present. Intelligence is usually normal, although learning difficulties and intellectual disability can occur, particularly in patients with large genomic deletions. Treatment is primarily surgical and focuses on correcting craniosynostosis to prevent increased intracranial pressure and to improve head shape and facial symmetry. Craniofacial surgery is typically performed in infancy or early childhood, and additional corrective procedures may be needed as the child grows. Management requires a multidisciplinary approach involving craniofacial surgeons, ophthalmologists, audiologists, and developmental specialists. Genetic counseling is recommended for affected families given the autosomal dominant inheritance pattern. Long-term follow-up is important to monitor for potential complications such as raised intracranial pressure, hearing loss, and dental anomalies.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Saethre-Chotzen syndrome