[Alobar holoprosencephaly. Prenatal diagnosis and autopsy findings in 2 cases]

We report two patients with alobar holoprosencephaly and cebocephaly: one, a fetus at 20th week of gestation; the second, a new born who died at seven days of age. Its very important U.S.G. in the prenatal diagnosis. Patients with holoprosencephaly and extracephalic malformation warrant chromosome analysis, because the incidence of chromosomal anomalies is very high. In the first foetus the brain and the face anomalies were associated with omphalocele, ureteropathy, bifid and horned uterus. In the second child karyotype analysis was normal. Cranial C.A.T. scan is important in the new born for the differential diagnosis holoprosencephaly from hydranencephaly, ventriculomegalia and Dandy-Walker cyst. The encephalon autopsy of both patients showed the presence of a single ventricule, the absence of interhemispheric fissure, of the corpus callosum and arrhinencephalia. This malformation complex is causally heterogeneous group. Chromosomal, autosomal recessive, autosomal dominant, and multifactorial mechanism have been invoked in humans; in animals it can be produced easily by a multitude of teratogenic agents. The two children reported are the first observation in the family. The etiology is presently unclear.