Middle interhemispheric variant of holoprosencephaly: A rare midline malformation.

Middle interhemispheric variant (MIH) of holoprosencephaly (HPE) or syntelencephaly is a rare variant of HPE characterized by abnormal midline union of the posterior frontal and parietal lobes with variable fusion of thalami. It varies from classic HPE in embryopathogenesis, severity of fusion of brain structures, associated craniofacial anomalies and clinical presentation. We report a case of MIH in a 5-year-old girl, who presented with severe developmental delay and discuss the features differentiating it from other more common forms of HPE.