Cerebro-fronto-facial syndrome (Dandy-Walker Variant and frontofacial dysmorphisms): report of the first case identified by increased nuchal translucency beyond 13(+6) weeks.

A 32-year-old gravida 2, para 1 woman, with a previous uneventful pregnancy, underwent first trimester ultrasound screening for Down syndrome at 13 weeks according to the Fetal Medicine Foundation guidelines (http://www.fetalmedicine.com/pdf/11-14/english/FMF-English.pdf). The ultrasound showed increased nuchal translucency (NT) of 8.9 mm with an estimated risk of Down syndrome of 1:8. Fetal karyotype was normal 46,XX by chorionic villus sampling. The patient underwent weekly ultrasound and at 19 weeks of gestation, a dilatation of the 4th ventricle with partial agenesis of the cerebellar vermis and normal posterior fossa were observed by transvaginal transcerebellar section of the fetal head. This finding was consistent with a diagnosis of Dandy-Walker variant and the patient opted for termination of pregnancy after extensive counselling. Autoptic examination confirmed the prenatal ultrasonographic findings and revealed signs of an underlying cerebro-fronto-facial syndrome due to the presence of facial dysmorphisms consistent with horizontal eyelid, high nasal root, low set ears and a wide forehead. Increased NT is not only a common phenotypic expression of chromosomal abnormalities, but is also associated with a wide range of fetal defects and genetic syndromes. Careful ultrasonographic follow-up is mandatory in all cases of increased first trimester nuchal translucency with normal karyotype in order to identify associated anomalies.