National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Acalvaria


Other Names:
Primary acalvaria
Categories:
Primary acalvaria is an extremely rare malformation characterized by the absence of the flat skull bones of the brain, dura mater, and scalp muscles. The skull base and facial features are fully formed and usually appear normal.[1][2][3] The cause of acalvaria is still unknown.[1]  Acalvaria can be distinguished from anencephaly, the most common differential diagnosis, by the presence of a layer of skin overlying the brain matter and normal cerebral hemispheres. [1] This malformation is most often lethal at birth due to other associated anomalies or to trauma during delivery, but a few surviving infants have been reported.[2]  Prenatal diagnosis via transvaginal ultrasound and/or magnetic resonance imaging is critical for better pregnancy management.   The initial treatment is conservative, mainly aimed at supportive care and management of any associated anomalies, if present. [1] Infants with acalvaria are managed conservatively in the newborn period because spontaneous bone growth has been seen in some newborns with other skull abnormalities, such as aplasia cutis congenita.   Skull reconstruction by bone grafting and cranioplasty at school age has been discussed in the literature. [1][4]
Last updated: 9/23/2013

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Aplasia/Hypoplasia of the cerebellum
Absent/small cerebellum
Absent/underdeveloped cerebellum
[ more ] 		0007360
30%-79% of people have these symptoms
Abnormality of neuronal migration 0002269
Calvarial skull defect
Cranial defect
Skull defect
[ more ] 		0001362
Postaxial hand polydactyly
Extra little finger
Extra pinkie finger
Extra pinky finger
[ more ] 		0001162
5%-29% of people have these symptoms
Abnormal lung lobation 0002101
Abnormality of cardiovascular system morphology 0030680
Cleft palate
Cleft roof of mouth
0000175
Holoprosencephaly 0001360
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Omphalocele 0001539
Spina bifida 0002414
Talipes 0001883
Percent of people who have these symptoms is not available through HPO
Anencephaly 0002323
Autosomal recessive inheritance 0000007
Congenital onset
Symptoms present at birth
0003577
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Last updated: 7/1/2020

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Acalvaria. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Gupta, V and Kumar, S.. Acalvaria: A rare congenital malformation. Journal of Pediatric Neuroscience. Sep - Dec 2012;
  2. Acalvaria. Orphanet. March 2006; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=945. Accessed 9/19/2013.
  3. Harris, C.. Acalvaria: A Unique Congenital Anomaly. American Journal of Medical Genetics. 1993;
  4. Khadilkar, VV., et.al.. Acalvaria. Indian Pediatrics. 2004;