Important
It is possible that the main title of the report Allan Herndon Syndrome
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
- X-Linked Mental Retardation with Hypotonia
- Allan-Herndon-Dudley Syndrome
- AHDS
- Allan-Herndon-Dudley Mental Retardation
Disorder Subdivisions
General Discussion
Allan-Herndon syndrome is an extremely rare inherited disorder that may be characterized by severe mental retardation, an impaired ability to form words and speak clearly (dysarthria), diminished muscle tone (hypotonia), and/or movement abnormalities.
With the exception of poor muscle tone, most affected infants appear to develop normally during the first months of life. However, by about six months of age, affected infants may seem weak and have an inability to hold up the head. Due to hypotonia, severely reduced motor development, and other abnormalities, affected children may not develop the ability to walk or may walk with difficulty. Associated features often include underdevelopment (hypoplasia) and wasting (atrophy) of muscle tissue; weakness and stiffness of the legs (spastic paraplegia) with exaggerated reflexes (hyperreflexia); relatively slow, involuntary, purposeless, writhing movements (athetoid movements); and/or other movement abnormalities. Affected individuals may also have abnormalities of the skull and facial (craniofacial) region. Allan-Herndon syndrome is thought to be inherited as an X-linked recessive trait and therefore is typically fully expressed in males only.
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Resources
WE MOVE (Worldwide Education and Awareness for Movement Disorders)
204 West 84th Street
New York, NY 10024
USA
Tel: 2128758312
Fax: 2128758389
Email: wemove@wemove.org
Internet: http://www.wemove.org
The Arc (a national organization on mental retardation)
1010 Wayne Ave
Suite 650
Silver Spring, MD 20910
Tel: (301)565-3842
Fax: (301)565-3843
Tel: (800)433-5255
TDD: (817)277-0553
Email: info@thearc.org
Internet: http://www.thearc.org/
NIH/Nat'l Institute on Deafness & Other Communication Disorders Information Clearinghouse
1 Communication Ave
Bethesda, MD 20892-3456
Tel: (301)402-0900
Fax: (301)907-8830
Tel: (800)241-1044
TDD: (800)241-1105
Email: nidcdinfo@nidcd.nih.gov
Internet: http://www.nidcd.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
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: 9/17/2007
Copyright 1996, 2001, 2003, 2007
National Organization for Rare Disorders, Inc.