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    Lissencephaly

    Important
    It is possible that the main title of the report Lissencephaly is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

    Synonyms

    • agyria
    • lissencephaly, type I

    Disorder Subdivisions

    • subcortical band heterotopia
    • Miller-Dieker syndrome
    • Norman-Roberts syndrome
    • isolated lissencephaly sequence (ILS)
    • lissencephaly 1 (LIS1)
    • x-linked lissencephaly

    General Discussion

    Classical lissencephaly, also known as lissencephaly type I, is a brain malformation that may occur as an isolated abnormality (isolated lissencephaly sequence [ILS]) or in association with certain underlying syndromes (e.g., Miller-Dieker syndrome, Norman-Roberts syndrome). The condition is characterized by absence (agyria) or incomplete development (pachygyria) of the ridges or convolutions (gyri) of the outer region of the brain (cerebral cortex), causing the brain's surface to appear unusually smooth.

    In infants with classical lissencephaly, the head circumference may be smaller than would otherwise be expected (microcephaly). Additional abnormalities may include sudden episodes of uncontrolled electrical activity in the brain (seizures), severe or profound intellectual disability, feeding difficulties, growth retardation, and impaired motor abilities. If an underlying syndrome is present, there may be additional symptoms and physical findings.

    Researchers indicate that there may be various possible causes of isolated lissencephaly, including viral infections or insufficient blood flow to the brain during fetal development or certain genetic factors. Changes (mutations) of at least two different genes have been implicated in isolated lissencephaly: a gene located on chromosome 17 (known as LIS1) and a gene located on the X-chromosome (known as XLIS or Doublecortin). There is a third gene known as TUBA1A that has been identified as the 3rd genetic cause for this disorder.

    Resources

    NIH/National Institute of Neurological Disorders and Stroke
    P.O. Box 5801
    Bethesda, MD 20824
    Tel: (301)496-5751
    Fax: (301)402-2186
    Tel: (800)352-9424
    TDD: (301)468-5981
    Internet: http://www.ninds.nih.gov/

    Genetic and Rare Diseases (GARD) Information Center
    PO Box 8126
    Gaithersburg, MD 20898-8126
    Tel: (301)251-4925
    Fax: (301)251-4911
    Tel: (888)205-2311
    TDD: (888)205-3223
    Internet: http://rarediseases.info.nih.gov/GARD/

    Madisons Foundation
    PO Box 241956
    Los Angeles, CA 90024
    Tel: (310)264-0826
    Fax: (310)264-4766
    Email: getinfo@madisonsfoundation.org
    Internet: http://www.madisonsfoundation.org

    For a Complete Report:

    This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

    The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

    It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

    This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

    For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

    Last Updated: 9/6/2012
    Copyright 1987, 1990, 1993, 1996, 1998, 1999, 2002, 2009, 2012 National Organization for Rare Disorders, Inc.

    WebMD Medical Reference from the National Organization for Rare Disorders

    Last Updated: May 28, 2015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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