Résumé
Miller-Dieker Syndrome (MDS) is a contiguous gene deletion syndrome of chromosome 17p13.3, characterized by classical lissencephaly (lissencephaly type 1) and distinct facial features. Children with MDS present with severe developmental delay, epilepsy and feeding problems. The lissencephaly represents the severe end of the spectrum with generalized agyria, or agyria and some frontal pachy- gyria. Prenatal diagnosis is available and consists of fetal chromosomal analysis by karyotyping or fluorescence in situ hybridization (FISH), on chorion villus sampling or amniocentesis. Sonographic diagnosis in general cannot be accomplished earlier than late second trimester, when the characteristic cerebral anomalies can be noted. The progressive microcephaly and failure of development of both sulci and gyri are suggestive of lissencephaly. We report the case of a pregnant woman of 24 weeks gestation who presented with ventriculomegaly on antenatal sonography and hydrocephalus, and corpus callosum agenesis on fetal MRI, which was diagnosed as MDS by karyotyping and FISH on amniocentesis.