Middle interhemispheric variant of holoprosencephaly

Abstract

A girl was born at gestational week 34 from a pregnancy complicated by pre-eclampsia and insulin-dependent diabetes mellitus. Multiple fetal anomalies were found on US (holoprosencephaly, cardiac situs inversus, ventricular septal defect and polyhydramnios). Fetal (Fig. 1) and postnatal (Fig. 2) brain MRIs show midline fusion of posterior frontal and anterior parietal regions with callosal dysgenesis and lack of midline thalamic fusion. Middle interhemispheric holoprosencephaly consists of abnormal midline hemispheric fusion of the posterior frontal and parietal regions. It differs from classic holoprosencephaly because there is interhemispheric separation of the basal forebrain and the anterior frontal lobes [1]. A