[Holoprosencephaly: criteria and consequences for prenatal diagnosis].

Two cases of prenatal diagnosis of holoprosencephaly are described. The characteristic sonographic findings in the second trimester were: microcephaly, absence of the midline echo, hypotelorism and typically flattened profile without sufficient configuration of the nose. Both foetuses had midline facial clefts, one of which was diagnosed prenatally. One case demonstrated a dorsal intracranial cyst. Analysis of the karyotype after foetal blood sampling and amniocentesis revealed translocation trisomy 13 in one case. The mother of this foetus had a balanced translocation 13/14. This foetus also had many extracranial abnormalities in contrast to the other foetus, which had a normal karyotype. Additionally we report of the prenatal diagnosis of a third case with cyclopia and trisomy 13. The findings of the autopsy of the foetuses are described and the criteria for prenatal diagnosis are compared to those found in the literature.