Format

Send to:

Choose Destination

Anencephalus

MedGen UID:
8068
Concept ID:
C0002902
Congenital Abnormality
Synonyms: Absence of a large part of the brain and the skull; Anencephaly
Modes of inheritance:
Multifactorial inheritance
MedGen UID:
109109
Concept ID:
C0600599
Genetic Function
Sources: HPO, Orphanet
A mode of inheritance that depends on a mixture of major and minor genetic determinants possibly together with environmental factors. Diseases inherited in this manner are termed complex diseases.
not inherited
MedGen UID:
832438
Concept ID:
CN227390
Intellectual Product
Source: Orphanet
Describes a disorder that is not inherited.
not inherited (Orphanet)
SNOMED CT: Anencephalus (89369001); Anencephaly (89369001); Anencephalic monster (89369001); Congenital absence of brain (89369001)
 
OMIM®: 206500
HPO: HP:0002323
Orphanet: ORPHA1048

Definition

Anencephaly is considered an extreme form of neural tube defect (182940), which has been associated with variation in several genes. The entity described here is believed to show autosomal recessive inheritance. [from OMIM]

Additional description

From GHR
Anencephaly is a condition that prevents the normal development of the brain and the bones of the skull. This condition results when a structure called the neural tube fails to close during the first few weeks of embryonic development. The neural tube is a layer of cells that ultimately develops into the brain and spinal cord. Because anencephaly is caused by abnormalities of the neural tube, it is classified as a neural tube defect.Because the neural tube fails to close properly, the developing brain and spinal cord are exposed to the amniotic fluid that surrounds the fetus in the womb. This exposure causes the nervous system tissue to break down (degenerate). As a result, people with anencephaly are missing large parts of the brain called the cerebrum and cerebellum. These brain regions are necessary for thinking, hearing, vision, emotion, and coordinating movement. The bones of the skull are also missing or incompletely formed.Because these nervous system abnormalities are so severe, almost all babies with anencephaly die before birth or within a few hours or days after birth.  https://ghr.nlm.nih.gov/condition/anencephaly

Clinical features

Anencephalus
MedGen UID:
8068
Concept ID:
C0002902
Congenital Abnormality
Anencephaly is considered an extreme form of neural tube defect (182940), which has been associated with variation in several genes. The entity described here is believed to show autosomal recessive inheritance.
Spina bifida
MedGen UID:
38283
Concept ID:
C0080178
Congenital Abnormality
Spina bifida is a condition in which the neural tube, a layer of cells that ultimately develops into the brain and spinal cord, fails to close completely during the first few weeks of embryonic development. As a result, when the spine forms, the bones of the spinal column do not close completely around the developing nerves of the spinal cord. Part of the spinal cord may stick out through an opening in the spine, leading to permanent nerve damage. Because spina bifida is caused by abnormalities of the neural tube, it is classified as a neural tube defect.Children born with spina bifida often have a fluid-filled sac on their back that is covered by skin, called a meningocele. If the sac contains part of the spinal cord and its protective covering, it is known as a myelomeningocele. The signs and symptoms of these abnormalities range from mild to severe, depending on where the opening in the spinal column is located and how much of the spinal cord is affected. Related problems can include a loss of feeling below the level of the opening, weakness or paralysis of the feet or legs, and problems with bladder and bowel control. Some affected individuals have additional complications, including a buildup of excess fluid around the brain (hydrocephalus) and learning problems. With surgery and other forms of treatment, many people with spina bifida live into adulthood.In a milder form of the condition, called spina bifida occulta, the bones of the spinal column are abnormally formed, but the nerves of the spinal cord usually develop normally. Unlike in the more severe form of spina bifida, the nerves do not stick out through an opening in the spine. Spina bifida occulta most often causes no health problems, although rarely it can cause back pain or changes in bladder function.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVAnencephalus
Follow this link to review classifications for Anencephalus in Orphanet.

Conditions with this feature

Anencephalus
MedGen UID:
8068
Concept ID:
C0002902
Congenital Abnormality
Anencephaly is considered an extreme form of neural tube defect (182940), which has been associated with variation in several genes. The entity described here is believed to show autosomal recessive inheritance.
Neural tube defect
MedGen UID:
18009
Concept ID:
C0027794
Congenital Abnormality
Neural tube defects are the second most common type of birth defect after congenital heart defects. The 2 most common NTDs are open spina bifida, also known as spina bifida cystica (SBC) or myelomeningocele, and anencephaly (206500) (Detrait et al., 2005). Spina bifida occulta (SBO), a bony defect of the spine covered by normal skin, is a mild form of spina bifida that is often asymptomatic. The term 'spinal dysraphia' refers to both SBC and SBO (Botto et al., 1999; Fineman et al., 1982). The most severe neural tube defect, craniorachischisis (CRN), leaves the neural tube open from the midbrain or rostral hindbrain to the base of the spine (summary by Robinson et al., 2012). Neural tube defects represent a complex trait with multifactorial etiology encompassing both genetic and environmental components (summary by Bartsch et al., 2012 and Lei et al., 2014). An X-linked form of spina bifida has been suggested; see 301410. See also folate-sensitive neural tube defects (601634), which are caused by genes involved in folate metabolism.
Type IV short rib polydactyly syndrome
MedGen UID:
96578
Concept ID:
C0432198
Disease or Syndrome
Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013). There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, 218330). For a discussion of genetic heterogeneity of short-rib thoracic dysplasia, see SRTD1 (208500).
XK aprosencephaly
MedGen UID:
167087
Concept ID:
C0795952
Disease or Syndrome
Anomalies of the prosencephalic structures, atelencephaly, and microcephaly in association with congenital heart diseases, preaxial limb malformations, eye abnormalities, and genital and other deformities. The disorder is frequently lethal. Infants who survive are severely retarded. Ring chromosome 13, duplication of the long arm of chromosome 13, and this syndrome share many common clinical features. In the synonym XK syndrome, the letter "X" stands for the unreported name of the patient of Garcia and Duncan, and "K" for the initial of Lurie's patient.
Pentalogy of Cantrell
MedGen UID:
374153
Concept ID:
C1839172
Meckel syndrome type 2
MedGen UID:
351059
Concept ID:
C1864148
Disease or Syndrome
Meckel syndrome is a rare autosomal recessive lethal condition characterized by an occipital meningoencephalocele, enlarged kidneys with multicystic dysplasia and fibrotic changes in the portal area of the liver and with ductal proliferation, and postaxial polydactyly. For a more complete phenotypic description and information on genetic heterogeneity, see MKS1 (249000).
Meckel syndrome type 5
MedGen UID:
409740
Concept ID:
C1969052
Disease or Syndrome
Meckel syndrome is a disorder with severe signs and symptoms that affect many parts of the body. The most common features are enlarged kidneys with numerous fluid-filled cysts; an occipital encephalocele, which is a sac-like protrusion of the brain through an opening at the back of the skull; and the presence of extra fingers and toes (polydactyly). Most affected individuals also have a buildup of scar tissue (fibrosis) in the liver.Other signs and symptoms of Meckel syndrome vary widely among affected individuals. Numerous abnormalities of the brain and spinal cord (central nervous system) have been reported in people with Meckel syndrome, including a group of birth defects known as neural tube defects. These defects occur when a structure called the neural tube, a layer of cells that ultimately develops into the brain and spinal cord, fails to close completely during the first few weeks of embryonic development. Meckel syndrome can also cause problems with development of the eyes and other facial features, heart, bones, urinary system, and genitalia.Because of their serious health problems, most individuals with Meckel syndrome die before or shortly after birth. Most often, affected infants die of respiratory problems or kidney failure.
Meckel syndrome type 4
MedGen UID:
410003
Concept ID:
C1970161
Disease or Syndrome
Meckel syndrome is an autosomal recessive pre- or perinatal lethal disorder characterized by a combination of renal cysts and variably associated features including developmental anomalies of the central nervous system (typically occipital encephalocele), hepatic ductal dysplasia and cysts, and postaxial polydactyly (summary by Baala et al., 2007). For a more complete phenotypic description and information on genetic heterogeneity of Meckel syndrome, see MKS1 (249000).
Meckel syndrome type 6
MedGen UID:
382942
Concept ID:
C2676790
Disease or Syndrome
Meckel syndrome is a disorder with severe signs and symptoms that affect many parts of the body. The most common features are enlarged kidneys with numerous fluid-filled cysts; an occipital encephalocele, which is a sac-like protrusion of the brain through an opening at the back of the skull; and the presence of extra fingers and toes (polydactyly). Most affected individuals also have a buildup of scar tissue (fibrosis) in the liver.Other signs and symptoms of Meckel syndrome vary widely among affected individuals. Numerous abnormalities of the brain and spinal cord (central nervous system) have been reported in people with Meckel syndrome, including a group of birth defects known as neural tube defects. These defects occur when a structure called the neural tube, a layer of cells that ultimately develops into the brain and spinal cord, fails to close completely during the first few weeks of embryonic development. Meckel syndrome can also cause problems with development of the eyes and other facial features, heart, bones, urinary system, and genitalia.Because of their serious health problems, most individuals with Meckel syndrome die before or shortly after birth. Most often, affected infants die of respiratory problems or kidney failure.
Anencephaly and spina bifida X-linked
MedGen UID:
419732
Concept ID:
C2931178
Disease or Syndrome
Hydrolethalus syndrome 2
MedGen UID:
481529
Concept ID:
C3279899
Disease or Syndrome
Hydrolethalus syndrome is an autosomal recessive embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs. Duplication of the hallux is a common finding. HLS2 is considered a ciliopathy (summary by Putoux et al., 2011). Acrocallosal syndrome (ACLS; 200990) is an allelic disorder with a less severe phenotype. For a discussion of genetic heterogeneity of hydrolethalus syndrome, see 236680.
Meckel syndrome, type 10
MedGen UID:
481666
Concept ID:
C3280036
Disease or Syndrome
Meckel syndrome is a disorder with severe signs and symptoms that affect many parts of the body. The most common features are enlarged kidneys with numerous fluid-filled cysts; an occipital encephalocele, which is a sac-like protrusion of the brain through an opening at the back of the skull; and the presence of extra fingers and toes (polydactyly). Most affected individuals also have a buildup of scar tissue (fibrosis) in the liver.Other signs and symptoms of Meckel syndrome vary widely among affected individuals. Numerous abnormalities of the brain and spinal cord (central nervous system) have been reported in people with Meckel syndrome, including a group of birth defects known as neural tube defects. These defects occur when a structure called the neural tube, a layer of cells that ultimately develops into the brain and spinal cord, fails to close completely during the first few weeks of embryonic development. Meckel syndrome can also cause problems with development of the eyes and other facial features, heart, bones, urinary system, and genitalia.Because of their serious health problems, most individuals with Meckel syndrome die before or shortly after birth. Most often, affected infants die of respiratory problems or kidney failure.
Meckel syndrome type 1
MedGen UID:
811346
Concept ID:
C3714506
Disease or Syndrome
Meckel syndrome, also known as Meckel-Gruber syndrome, is a severe pleiotropic autosomal recessive developmental disorder caused by dysfunction of primary cilia during early embryogenesis. There is extensive clinical variability and controversy as to the minimum diagnostic criteria. Early reports, including that of Opitz and Howe (1969) and Wright et al. (1994), stated that the classic triad of Meckel syndrome comprises (1) cystic renal disease; (2) a central nervous system malformation, most commonly occipital encephalocele; and (3) polydactyly, most often postaxial. However, based on a study of 67 patients, Salonen (1984) concluded that the minimum diagnostic criteria are (1) cystic renal disease; (2) CNS malformation, and (3) hepatic abnormalities, including portal fibrosis or ductal proliferation. In a review of Meckel syndrome, Logan et al. (2011) stated that the classic triad first described by Meckel (1822) included occipital encephalocele, cystic kidneys, and fibrotic changes to the liver. Genetic Heterogeneity of Meckel Syndrome See also MKS2 (603194), caused by mutation in the TMEM216 gene (613277) on chromosome 11q13; MKS3 (607361), caused by mutation in the TMEM67 gene (609884) on chromosome 8q; MKS4 (611134), caused by mutation in the CEP290 gene (610142) on chromosome 12q; MKS5 (611561), caused by mutation in the RPGRIP1L gene (610937) on chromosome 16q12.2; MKS6 (612284), caused by mutation in the CC2D2A gene (612013) on chromosome 4p15; MKS7 (267010), caused by mutation in the NPHP3 (608002) gene on chromosome 3q22; MKS8 (613885), caused by mutation in the TCTN2 gene (613846) on chromosome 12q24.31; MKS9 (614209), caused by mutation in the B9D1 gene (614144) on chromosome 17p11.2; MKS10 (614175), caused by mutation in the B9D2 gene (611951) on chromosome 19q13; MKS11 (615397), caused by mutation in the TMEM231 gene (614949) on chromosome 16q23; MKS12 (616258), caused by mutation in the KIF14 gene (611279) on chromosome 1q31; and MKS13 (617562), caused by mutation in the TMEM107 gene (616183) on chromosome 17p13.
Short-rib thoracic dysplasia 14 with polydactyly
MedGen UID:
901479
Concept ID:
C4225286
Disease or Syndrome
Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013). There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, 218330). For a discussion of genetic heterogeneity of short-rib thoracic dysplasia with or without polydactyly, see SRTD1 (208500).

Recent clinical studies

Etiology

Borman B, Cryer C
J Paediatr Child Health 1993 Aug;29(4):282-8. PMID: 8373673
Borman GB, Smith AH, Howard JK
Teratology 1986 Apr;33(2):221-30. doi: 10.1002/tera.1420330209. PMID: 3526620
Elwood JH, Elwood JM
Int J Epidemiol 1984 Mar;13(1):45-52. PMID: 6538186
Strassburg MA, Greenland S, Portigal LD, Sever LE
Dev Med Child Neurol 1983 Oct;25(5):632-41. PMID: 6354801
Nevin NC, Johnston WP
J Med Genet 1980 Jun;17(3):203-11. PMID: 6995614Free PMC Article

Diagnosis

Park MI, Kim DS
J Perinat Med 1989;17(5):329-31. PMID: 2625655
Stone DH
Dev Med Child Neurol 1987 Aug;29(4):541-6. PMID: 3315792
Borman GB, Howard JK, Chapman CJ
N Z Med J 1986 Mar 26;99(798):183-5. PMID: 3486390
Greenberg M, Krim EY, Mastrota VF, Rosenfeld DL, Goldman M, Fenton AN
J Reprod Med 1981 Nov;26(11):593-4. PMID: 6802970
Gardner WJ
Childs Brain 1979;5(4):361-79. PMID: 456110

Therapy

Elwood JH, Elwood JM
Int J Epidemiol 1984 Mar;13(1):45-52. PMID: 6538186
Strassburg MA, Greenland S, Portigal LD, Sever LE
Dev Med Child Neurol 1983 Oct;25(5):632-41. PMID: 6354801
Elwood JM, Elwood JH
Int J Epidemiol 1982 Jun;11(2):132-7. PMID: 6980196
Elwood JM, Coldman AJ
Am J Epidemiol 1981 Jun;113(6):681-90. PMID: 7234857
Greenberg M, Krim EY, Mastrota VF, Rosenfeld DL, Goldman M, Fenton AN
J Reprod Med 1981 Nov;26(11):593-4. PMID: 6802970

Prognosis

Ciranni R, Fornaciari G, Nardini V, Caramella D
Med Secoli 2008;20(1):7-17. PMID: 19569409
Lekea V, Tzoumaka-Bakoula C, Golding J
Teratology 1988 Oct;38(4):347-9. doi: 10.1002/tera.1420380406. PMID: 3070811
Gardner WJ
Childs Brain 1979;5(4):361-79. PMID: 456110
Elwood JM
Br J Prev Soc Med 1976 Mar;30(1):29-31. PMID: 949570Free PMC Article
Rogers SC
Br J Prev Soc Med 1976 Mar;30(1):26-8. PMID: 779911Free PMC Article

Clinical prediction guides

Elwood JH, Elwood JM
Int J Epidemiol 1984 Mar;13(1):45-52. PMID: 6538186
Strassburg MA, Greenland S, Portigal LD, Sever LE
Dev Med Child Neurol 1983 Oct;25(5):632-41. PMID: 6354801
Sever LE, Emanuel I
Dev Med Child Neurol 1981 Apr;23(2):151-4. PMID: 7011886
Elwood JM
Br J Prev Soc Med 1976 Mar;30(1):29-31. PMID: 949570Free PMC Article
Rogers SC
Br J Prev Soc Med 1976 Mar;30(1):26-8. PMID: 779911Free PMC Article

Recent systematic reviews

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...
Support Center