Saethre-Chotzen syndrome (SCS) is caused by either sequence variants or deletions of the TWIST1 gene. It is inherited in an autosomal dominant manner. Mutations may be inherited from an affected parent or may be de novo.
SCS is characterized by coronal synostosis, facial asymmetry, ptosis, and a distinctive ear appearance of a small pinna with prominent crus. In some cases there may also be syndactyly of digits 2 and 3 on the hand. Intellect is generally normal, although individuals with a large deletion are more likely to have developmental delays.
This laboratory performs both Sanger sequencing of the TWIST1 gene and deletion/duplication by MLPA.