Prenatal diagnosis of ring chromosome 6 in a fetus with cerebellar hypoplasia and partial agenesis of corpus callosum: case report and review of the literature.

Ring chromosome 6 (RC6) is a rare constitutional abnormality, with variable material loss, leading to a variable clinical phenotype: minimal physical anomalies and mild psychomotor retardation to severe physical and mental defects. Among the 22 published cases, only five have been prenatally detected. We describe here a RC6 prenatally diagnosed.