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Disease Profile


Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable



Congenital and Genetic Diseases; Nervous System Diseases


Schizencephaly is a rare congenital (present from birth) brain malformation in which abnormal slits or clefts form in the cerebral hemispheres of the brain. The signs and symptoms of this condition may include developmental delay, seizures, and problems with brain-spinal cord communication. People with schizencephaly may also have an abnormally small head (microcephaly); hydrocephalus; intellectual disability; partial or complete paralysis; and/or poor muscle tone (hypotonia).[1] Severity of symptoms depends on many factors including the extent of the clefting and whether or not other brain abnormalities are present.[2] Although the exact cause of schizencephaly is unknown, it has been linked to a variety of genetic and non-genetic factors.[2][3] Treatment generally consists of physical therapy and drugs to prevent seizures. In cases that are complicated by hydrocephalus, a surgically implanted tube, called a shunt, is often used to divert fluid to another area of the body where it can be absorbed.[1]


Signs and symptoms of schizencephaly may include:[1][2]

  • Developmental delay
  • Seizures
  • Abnormally small head (microcephaly)
  • Intellectual disability
  • Partial or complete paralysis
  • Poor muscle tone (hypotonia)
  • Hydrocephalus

Severity of symptoms depends on many factors, including the extent of the clefting and whether or not other brain abnormalities are present. For example, people with a small cleft in one hemisphere may have paralysis on one side of the body and little to no intellectual disability, while clefts in both hemispheres can lead to quadriplegia (paralysis of both arms and legs) and severe intellectual disability.[2]

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.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Aplasia/Hypoplasia of the corpus callosum
EEG abnormality
Porencephalic cyst
Cavity within brain
Squint eyes

[ more ]

30%-79% of people have these symptoms
Global developmental delay
Weakness of one side of body
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific

[ more ]

Spastic tetraplegia
Percent of people who have these symptoms is not available through HPO
Agenesis of corpus callosum
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells


The exact cause of schizencephaly is unknown.[4] A small number of people with schizencephaly are found to have changes (mutations) in one of four genes: EMX2, SIX3, SHH, and COL4A1.[5][3][6] Rarely, schizencephaly can affect more than one family member.[4][7][8][9] This supports a genetic cause in some cases.[4]

Schizencephaly has also been linked to a variety of non-genetic factors, including young maternal age and certain medications and infections that can cause vascular disruptions (disruption of blood flow or blood supply) in a developing baby.[2]


Schizencephaly is typically diagnosed by computed tomography (CT) and/or magnetic resonance imaging (MRI).[2] A CT scan is an imaging method that uses x-rays to create pictures of cross-sections of the body, while an MRI scan uses powerful magnets and radio waves to create pictures of the brain and surrounding nerve tissues. Both of these imaging methods can be used to identify brain abnormalities such as the slits or clefts found in people with schizencephaly.

In some cases, schizencephaly can also be diagnosed prenatally (before birth) on ultrasound after 20 weeks gestation. If clefting is seen on ultrasound, an MRI scan of the developing baby may be recommended to confirm the diagnosis.[2][10]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.


    The best treatment options for people with schizencephaly depend on many factors, including the severity of the condition and the signs and symptoms present. For example, people with developmental delay (i.e. delayed motor milestones) or partial paralysis may be referred for physical therapy and/or occupational therapy. Medications are often prescribed to prevent seizures. In cases that are complicated by hydrocephalus, a surgically implanted tube, called a shunt, is often used to divert fluid to another area of the body where it can be absorbed.[1][2]


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Social Networking Websites

        Organizations Providing General Support

          Learn more

          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.

          Where to Start

            In-Depth Information

            • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
            • 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 Schizencephaly. Click on the link to view a sample search on this topic.


              1. NINDS Schizencephaly Information Page. National Institute of Neurological Disorders and Stroke. April 16, 2014; https://www.ninds.nih.gov/disorders/schizencephaly/schizencephaly.htm. Accessed 11/17/2014.
              2. Schizencephaly. Orphanet. May 2014; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=799. Accessed 11/17/2014.
              3. Schizencephaly. OMIM. May 2014; https://omim.org/entry/269160. Accessed 11/17/2014.
              4. Hilburger AC, Willis JK, Bouldin E, Henderson-Tilton A. Familial schizencephaly. Brain & Development. May-June 1993; 15(3):234-236. https://www.ncbi.nlm.nih.gov/pubmed/8214352. Accessed 4/28/2011.
              5. Yoneda et al. Phenotypic spectrum of COL4A1 mutations: porencephaly to schizencephaly. Ann. Neurol. 2013; 73:48-57. Accessed 11/18/2014.
              6. Hehr U et al. Heterozygous mutations in SIX3 and SHH are associated with schizencephaly and further expand the clinical spectrum of holoprosencephaly. Human Genetics. March 2010; 127(5):555-561. https://www.ncbi.nlm.nih.gov/pubmed/20157829. Accessed 4/28/2011.
              7. Hosley, M. A., Abroms, I. F., Ragland, R. L. Schizencephaly: case report of familial incidence. Pediat. Neurol. 1992; 8:148-150. Accessed 11/18/2014.
              8. Robinson, R. O. Familial schizencephaly. Dev. Med. Child Neurol. 1991; 33:1010-1014. Accessed 11/18/2014.
              9. Tietjen I, Erdogan F, Currier S, Apse K, Chang BS, Hill RS, Lee CK, Walsh CA. EMX2-independent familial schizencephaly: clinical and genetic analyses. Am J Med Genet A. June 2005; 135(2):166-170. Accessed 11/18/2014.
              10. Ken R Close, MD. Schizencephaly Imaging. Medscape. November 2013; https://emedicine.medscape.com/article/413051-overview. Accessed 11/18/2014.

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