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

Mitochondrial function changes as we age

(Phys.org)—A new study finds that age-related onset of type 2 diabetes and impaired glucose tolerance may be due to the lowered ability of muscle mitochondria to switch from metabolizing fatty acids to metabolizing glucose ...

New role for an old protein: Cancer causer

A protein known to play a role in transporting the molecular contents of normal cells into and out of various intracellular compartments can also turn such cells cancerous by stimulating a key growth-control pathway.