Holoprosencephaly: A Defect in Brain Patterning

Alobar holoprosencephaly: A case report

Holoprosencephaly (HPE) is a rare congenital brain malformation associated with multiple midline facial defects. This anomaly is resulted from the failure of diverticulation and cleavage of primitive prosencephalon during weeks 4-8 of gestation. HPE is the most common forebrain developmental anomaly in human with the incidence rate of 0.49-1.2 cases per 10,000-20,000 term births. In this study,...

Holoprosencephaly

Zic2-associated holoprosencephaly is caused by a transient defect in the organizer region during gastrulation.

The putative transcription factor ZIC2 is associated with a defect of forebrain development, known as Holoprosencephaly (HPE), in humans and mouse, yet the mechanism by which aberrant ZIC2 function causes classical HPE is unexplained. The zinc finger domain of all mammalian Zic genes is highly homologous with that of the Gli genes, which are transcriptional mediators of Shh signalling. Mutation...

Holoprosencephaly

Holoprosencephaly (HPE) is a complex brain malformation resulting from incomplete cleavage of the prosencephalon, occurring between the 18th and the 28th day of gestation and affecting both the forebrain and the face. It is estimated to occur in 1/16,000 live births and 1/250 conceptuses. Three ranges of increasing severity are described: lobar, semi-lobar and alobar HPE. Another milder subtype...

Early prenatal diagnosis of semilobar holoprosencephaly combined with a dorsal cyst and no facial defect.