Diseases & Conditions


Megalocornea Mental Retardation Syndrome

Synonyms of Megalocornea Mental Retardation Syndrome
  • MMR Syndrome
  • Neuhauser Syndrome

Disorder Subdivisions

    General Discussion
    Megalocornea-Mental Retardation Syndrome is an extremely rare genetic disorder characterized by distinctive abnormalities of the eyes, diminished muscle tone that is apparent at birth (congenital hypotonia), and varying degrees of mental retardation. In some cases, additional abnormalities may also be present. The range and severity of symptoms and physical findings may vary from case to case.

    In most infants with Megalocornea-Mental Retardation Syndrome, the front, clear portion of the eyes through which light passes may be abnormally large (megalocornea). Both eyes are usually affected (bilateral involvement). Many affected infants also have additional eye (ocular) abnormalities including underdevelopment of the colored portion of the eyes (iris hypoplasia), abnormal unsteadiness of the irises during eye movements (iridodonesis), and/or other ocular abnormalities, potentially leading to varying degrees of visual impairment. In addition to abnormally diminished muscle tone (hypotonia), most affected infants also have additional neuromuscular abnormalities including abnormal delays in the acquisition of skills requiring the coordination of mental and muscular activities (psychomotor retardation) and/or an impaired ability to coordinate voluntary movements (ataxia). In most cases, affected infants and children also have moderate to severe mental retardation.

    In some cases, infants and children with Megalocornea-Mental Retardation Syndrome may have additional abnormalities including short stature; episodes of uncontrolled electrical disturbances in the brain (seizures); and/or certain distinctive abnormalities of the head and facial (craniofacial) area. Such craniofacial malformations may include an unusually prominent forehead (frontal bossing), widely spaced eyes (ocular hypertelorism), a long upper lip, an abnormally small lower jaw (hypoplastic mandible), and/or unusually large and/or cup-shaped ears. In most cases, Megalocornea-Mental Retardation Syndrome appears to occur randomly for unknown reasons (sporadically). In other cases, the disorder is thought to be inherited as an autosomal recessive genetic trait.

    Organizations related to Megalocornea Mental Retardation Syndrome
    • Children's Craniofacial Association
      13140 Coit Road
      Dallas TX 75240
      Phone #: 214-570-9099
      800 #: 800-535-3643
      e-mail: [email protected]
      Home page: http://www.ccakids.com
    • Council of Families with Visual Impairment
      1155 15th St. NW
      Washington DC 20005
      Phone #: 202-465-5081
      800 #: --
      e-mail: [email protected]
      Home page: http://www.acb.org/
    • Craniofacial Foundation of America
      975 East Third Street
      Chattanooga TN 37403
      Phone #: 423-778-9192
      800 #: 800-418-3223
      e-mail: [email protected]
      Home page: http://www.craniofacialcenter.com
    • Glaucoma Research Foundation
      490 Post Street
      San Francisco CA 94102
      Phone #: 415-986-3162
      800 #: 800-826-6693
      e-mail: [email protected]
      Home page: http://www.glaucoma.org
    • Human Growth Foundation
      997 Glen Cove Avenue
      Glen Head NY 11545
      Phone #: 516-671-4041
      800 #: 800-451-6434
      e-mail: [email protected]
      Home page: http://www.hgfound.org/
    • NIH/National Eye Institute
      Building 31 Rm 6A32
      Bethesda MD 20892-2510
      Phone #: 301-496-5248
      800 #: --
      e-mail: [email protected]
      Home page: http://www.nei.nih.gov/
    • National Association for Parents of Children with Visual Impairments (NAPVI)
      P.O. Box 317
      Watertown MA 02472
      Phone #: 617-972-7441
      800 #: 800-562-6265
      e-mail: [email protected]
      Home page: http://www.napvi.org
    • National Association for Visually Handicapped
      22 West 21st Street
      New York NY 10010
      Phone #: 212-889-3141
      800 #: --
      e-mail: [email protected]
      Home page: http://www.navh.org
    • National Institute of Neurological Disorders and Stroke (NINDS)
      31 Center Drive
      Bethesda MD 20892-2540
      Phone #: 301-496-5751
      800 #: 800-352-9424
      e-mail: [email protected]
      Home page: http://www.ninds.nih.gov/

    For a Complete Report

    This is an abstract of a report from the National Organization for Rare Disorders, Inc. ? (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html