Fetal Skeletal Dysplasias that Involve the Face: Binder Syndrome and Nager Syndrome.

Binder syndrome and Nager syndrome are part of the spectrum of skeletal dysplasias. Although exceedingly rare, both syndromes are amenable to prenatal diagnosis because they present with features that can be detected by prenatal ultrasound. Genetic prenatal diagnosis is sometimes possible but remains difficult if the etiology of the disease is not homogenous. In cases of severe skeletal dysplasias, the prognosis is unfavorable irrespectively of the genetic defect. In cases with only mild structural anomalies, prenatal counselling is especially difficult. We present cases of Binder syndrome and Nager syndrome diagnosed by us prenatally. We elaborate on the etiology of Binder syndrome and discuss the current classification of facial dysostoses.