Synonyms

• MMR Syndrome
• Neuhauser Syndrome

Disorder Subdivisions

• None

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.

Resources

Human Growth Foundation
997 Glen Cove Avenue
Glen Head, NY 11545
Tel: (516)671-4041
Fax: (516)671-4055
Tel: (800)451-6434
Email: hgf1@hgfound.org
Internet: http://www.hgfound.org/

Children's Craniofacial Association
13140 Coit Road
Suite 517
Dallas, TX 75240
USA
Tel: 2145709099
Fax: 2145708811
Tel: 8005353643
Email: csmith@ccakids.com
Internet: http://www.ccakids.com

National Association for Visually Handicapped
22 West 21st Street
New York, NY 10010
USA
Tel: 2128893141
Fax: 2127272931
Email: staff@navh.org
Internet: http://www.navh.org

National Association for Parents of Children with Visual Impairments (NAPVI)
P.O. Box 317
Watertown, MA 02472
Tel: (617)972-7441
Fax: (617)972-7444
Tel: (800)562-6265
Email: napvi@perkins.org
Internet: http://www.napvi.org

Council of Families with Visual Impairment
1155 15th St. NW
Suite 1004
Washington, DC 20005
Tel: (202)465-5081
Fax: (202)465-5085
Email: info@acb.org
Internet: http://www.acb.org/

Glaucoma Research Foundation
490 Post Street
Suite 1427
San Francisco, CA 94102
Tel: (415)986-3162
Fax: (415)986-3763
Tel: (800)826-6693
Email: info@glaucoma.org
Internet: http://www.glaucoma.org

NIH/National Eye Institute
Building 31 Rm 6A32
31 Center Dr MSC 2510
Bethesda, MD 20892-2510
United States
Tel: 3014965248
Fax: 3014021065
Email: 2020@nei.nih.gov
Internet: http://www.nei.nih.gov/

National Institute of Neurological Disorders and Stroke (NINDS)
31 Center Drive
8A07
Bethesda, MD 20892-2540
Tel: (301)496-5751
Fax: (301)402-2186
Tel: (800)352-9424
Email: braininfo@ninds.nih.gov
Internet: http://www.ninds.nih.gov/

Craniofacial Foundation of America
975 East Third Street
Chattanooga, TN 37403
Tel: (423)778-9192
Fax: (423)778-8172
Tel: (800)418-3223
Email: farmertm@erlanger.org
Internet: http://www.craniofacialcenter.com

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

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:  4/25/2008
Copyright  1997, 1998, 1999National Organization for Rare Disorders, Inc.