Holoprosencephaly

Holoprosencephaly (HPE, once known as arhinencephaly) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres. Normally, the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy. Hox genes, which guide placement of embryonic structures, fail to activate along the midline of the head, allowing structures that are normally paired on the left and right to merge. The condition also occurs in other species, as with Cy, the Cyclops kitten.

The condition can be mild or severe. According to the National Institute of Neurological Disorders and Stroke (NINDS), "in most cases of holoprosencephaly, the malformations are so severe that babies die before birth.

When the embryo's forebrain does not divide to form bilateral cerebral hemispheres (the left and right halves of the brain), it causes defects in the development of the face and in brain structure and function.

In less severe cases, babies are born with normal or near-normal brain development and facial deformities that may affect the eyes, nose, and upper lip.

This text uses material from Wikipedia licensed under CC BY-SA

Latest Spotlight News

New 'Tissue Velcro' could help repair damaged hearts

Engineers at the University of Toronto just made assembling functional heart tissue as easy as fastening your shoes. The team has created a biocompatible scaffold that allows sheets of beating heart cells to snap together ...

Closing the loop with optogenetics

An engineering example of closed-loop control is a simple thermostat used to maintain a steady temperature in the home. Without it, heating or air conditioning would run without reacting to changes in outside conditions, ...