Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Syntelencephaly, also known as middle interhemispheric variant of holoprosencephaly, is a rare congenital malformation characterized by the non-cleavage of cerebral hemispheres in the posterior frontal and parietal regions. Mutation of the ZIC2 gene that controls hemispherization has been reported in syntelencephaly, as well as in classic holoprosencephaly, suggesting that syntelencephaly is among the variant of holoprosencephaly. Clinically, patients usually are less symptomatic than those with other forms of holoprosencephaly, often presenting with mild to moderate cognitive impairment. The classic imaging finding is the continuous cerebral hemisphere in posterior frontal and parietal lobes (A, arrows). On sagittal T1WI, the corpus callosal body is absent, while the splenium (B, yellow arrow) and anterior genu (B, white arrow) are formed.