Holoprosencephaly

Holoprosencephaly
Holoprosencephaly
	Diagram depicting the main subdivisions of the embryonic vertebrate brain.
Specialty	Medical genetics

Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres, typically occurring between the 18th and 28th day of gestation.^[1] Normally, the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy. The condition also occurs in other species.

Holoprosencephaly is estimated to occur in approximately 1 in every 250 conceptions^[1] and most cases are not compatible with life and result in fetal death in utero due to deformities to the skull and brain.^[2] However, holoprosencephaly is still estimated to occur in approximately 1 in every 8,000 live births.^[3]

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.

The severity of holoprosencephaly is highly variable. 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.^[1]

^ ^a ^b ^c Dubourg, Christèle; Bendavid, Claude; Pasquier, Laurent; Henry, Catherine; Odent, Sylvie; David, Véronique (2007). "Holoprosencephaly". Orphanet Journal of Rare Diseases. 2 (1): 8. doi:10.1186/1750-1172-2-8. ISSN 1750-1172. PMC 1802747. PMID 17274816.
^ "Holoprosencephaly Information Page". National Institute of Neurological Disorders and Stroke. National Institutes of Health, U.S. Department of Health & Human Services.
^ Raam, Manu S; Solomon, Benjamin D; Muenke, Maximilian (June 2011). "Holoprosencephaly: A Guide to Diagnosis and Clinical Management". Indian Pediatrics. 48 (6): 457–466. doi:10.1007/s13312-011-0078-x. ISSN 0019-6061. PMC 4131946. PMID 21743112.

[Dubourg2007-1] Dubourg, Christèle; Bendavid, Claude; Pasquier, Laurent; Henry, Catherine; Odent, Sylvie; David, Véronique (2007). "Holoprosencephaly". Orphanet Journal of Rare Diseases. 2 (1): 8. doi:10.1186/1750-1172-2-8. ISSN 1750-1172. PMC 1802747. PMID 17274816.

[2] "Holoprosencephaly Information Page". National Institute of Neurological Disorders and Stroke. National Institutes of Health, U.S. Department of Health & Human Services.

[Raam2011-3] Raam, Manu S; Solomon, Benjamin D; Muenke, Maximilian (June 2011). "Holoprosencephaly: A Guide to Diagnosis and Clinical Management". Indian Pediatrics. 48 (6): 457–466. doi:10.1007/s13312-011-0078-x. ISSN 0019-6061. PMC 4131946. PMID 21743112.

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