Setleis Syndrome in Mexican-Nahua Sibs Due to a Homozygous TWIST2 Frameshift Mutation and Partial Expression in Heterozygotes: Review of the Focal Facial Dermal Dysplasias and Subtype Reclassification

Setleis syndrome, a type of focal facial derma dysplasia (FFDD), is a genetic abnormality involving fetal development of the face.  Setleis syndrome may have several genetic causes, but two mutations in the TWIST2 gene have been identified previously.  Patients are born with scar-like, “forcep” marks in their temporal regions along with other syndromic features.   Two Mexican siblings with the typical Setleis features were found to have a third TWIST2 mutation, further confirming the recessive inheritance of the disorder.   Of note, relatives who are only carriers for the mutation also have subtle syndromic features.  A review of all previously reported FFDD cases resulted in a re-classification of the subtypes. (By Amy Yang, MD, http://jmg.bmj.com/content/48/10/716 )