Ablepharon macrostomia syndrome is genetic disorder characterized by absent eyelids (ablepharon) and very large mouth (macrostomia). Other common signs and symptoms include abnormal external ears, fusion (syndactyly) of the hands and feet, skin findings (such as dry and coarse skin or redundant folds of skin), absent or sparse hair, genital malformations, and developmental delay. Other reported findings include underdeveloped cheeks (malar hypoplasia), absent or very small (hypoplastic) nipples, umbilical abnormalities and growth retardation. It belongs to a group of diseases called ectodermal dysplasias (genetic disorders that involve defects in the skin, hair, nails, sweat glands, and/or teeth). Ablepharon macrostomia syndrome is caused by genetic changes in the TWIST2 gene. Inheritance is autosomal dominant, but most cases are sporadic (when there are no other cases in the family). Genetic changes in TWIST2 gene also cause the Barber Say syndrome and Setleis syndrome, other ectodermal dysplasia syndromes which have very similar features.