Recurrent autosomal dominant mutations in the DNA binding domain of the TWIST2 gene lead to two rare congenital abnormality disorders, Barber–Say syndrome (BSS) and ablepharon–macrostomia syndrome (AMS), which are expressed as dysmorphic facial characteristics and congenital malformations caused by ectodermal dysplasias [40]. The gene discussed is TWIST2; the disease is Barber-Say syndrome.