The focal facial dermal dysplasias: phenotypic spectrum and molecular genetic heterogeneity

Focal Facial Dermal Dysplasias (FFDDs) are four developmental genetic disorders with similar bilateral “scar-like” facial lesions at birth and are classified by the lesion location: bitemporal for the FFDD subtypes 1-3 and peri-auricular for FFDD subtype 4. This review summarizes the clinical features of the subtypes and the genetic defects underlying FFDD3 and FFDD4, while the underlying genetic defects in FFDD1 and FFDD2 remain unknown. Additionally, two autosomal dominant developmental disorders with overlapping facial lesions, Ablepharon-Macrostomia syndrome and Barber-Say syndrome, are discussed. Recognition of these disorders and further investigation of their genetic defects may provide insights into the genetic pathways of facial development. (By Brenden Chen, )