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]
^"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.
of holoprosencephaly as well as a “microform". These classifications can be distinguished by their anatomical differences. Alobar holoprosencephaly Small...
character cyclopes), also known as alobar holoprosencephaly, is the most extreme form of holoprosencephaly and is a congenital disorder (birth defect)...
(2) agnathia with holoprosencephaly; (3) agnathia with situs inversus and visceral anomalies; and (4) agnathia with holoprosencephaly, situs inversus,...
disorder caused by holoprosencephaly. Ethmocephaly is the rarest phenotypic variant of a group of defects called the holoprosencephaly (HPE) malformation...
divide the brain into two lobes, it results in a condition known as holoprosencephaly. The parts present in the forebain are cerebrum, thalamus and hypothalamus...
a developmental anomaly that is part of a group of defects called holoprosencephaly. Cebocephaly involves the presence of two separate eyes set close...
hedgehog acyltransferase (HHAT) gene that have caused acrania along with holoprosencephaly and agnathia. The mutation in HHAT which causes this disease is a...
sonic hedgehog gene in holoprosencephaly: SHH mutations cause a significant proportion of autosomal dominant holoprosencephaly". Human Molecular Genetics...
have also been found in holoprosencephaly patients. Some of these patients present cleft lip and palate among the holoprosencephaly features, and missense...
synophrys to severe congenital anomalies, such as heart defects and holoprosencephaly. In some cases, dysmorphic features are part of a larger clinical...
with ring 18. In some children without “classic” holoprosencephaly, microforms of holoprosencephaly may be noted on MRI, including missing olfactory tracts...
affected: Common central nervous system defects seen in triploidy include holoprosencephaly, hydrocephalus (increased amount of cerebrospinal fluid within the...
development and in the adult. Mutations in this gene are associated with holoprosencephaly type 4, which is a structural anomaly of the brain. It has also been...
can cause prolonged gestation associated with birth defects such as holoprosencephaly and cyclopia in animals such as sheep, horses, and other mammals that...
Mutations in SIX3 are the cause of a severe brain malformation, called holoprosencephaly type 2 (HPE2). In HPE2, the brain fails to separate into two hemispheres...
abnormalities, frequently coexist with Agnathia. Agnathia is seen in agnathia-holoprosencephaly, otocephaly, and Ivemark syndrome. X-rays or CT scans of the mandible...
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