Vertical course of fetal anterior cerebral artery as clue to prenatal diagnosis of syntelencephaly

Syntelencephaly, also known as middle interhemispheric variant of holoprosencephaly, is a subtype of holoprosencephaly characterized by the absence of midline cleavage between the posterior parts of the frontal lobes and anterior parts of the parietal lobes1. It differs from the lobar form of holoprosencephaly, which is characterized by non-separation of the basal forebrain. Clinical manifestations of syntelencephaly include developmental delay, spasticity and epilepsy. Hypertelorism is sometimes observed1. Only 15 cases of prenatally diagnosed syntelencephaly have been reported in the literature2. In these reports, the first warning signs on ultrasound were the absence of the cavum septi pellucidi,