Skip to Content

Health Library

MCT8-specific thyroid hormone cell transporter deficiency

National Organization for Rare Disorders, Inc.

Important
It is possible that the main title of the report MCT8-specific thyroid hormone cell transporter deficiency 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

  • AHDS
  • MCT8-THCT deficiency
  • Allan-Herndon-Dudley syndrome
  • Allan-Herndon syndrome
  • mental retardation, X-linked, with hypotonia
  • THCT deficiency

Disorder Subdivisions

  • None

General Discussion

MCT8-specific thyroid hormone cell transporter deficiency (THCT deficiency) is an inherited disorder that is characterized by severe mental retardation, an impaired ability to speak, 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 two 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 very rarely develop any ability to walk and when they do, it is with shuffling gait. 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, commonly dyskinetic (abnormal movement) attacks. Writhing movements (athetoid movements); and/or other movement abnormalities are less common. Affected individuals may also have abnormalities of the skull and facial (craniofacial) region. THCT deficiency is inherited as an X-linked genetic disorder.

Resources

WE MOVE (Worldwide Education and Awareness for Movement Disorders)
5731 Mosholu Avenue
Bronx, NY 10471
USA
Tel: (347)843-6132
Fax: (718)601-5112
Email: wemove@wemove.org
Internet: http://www.wemove.org

The Arc
1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255
TDD: (817)277-0553
Email: info@thearc.org
Internet: http://www.thearc.org

NIH/National Institute on Deafness and Other Communication Disorders
31 Center Drive, MSC 2320
Communication Avenue
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

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/

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:  2/1/2010
Copyright  1996, 2001, 2003, 2007, 2009, 2010 National Organization for Rare Disorders, Inc.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

Decision Points

Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.

You'll find Decision Points to help you answer questions about:

Interactive Tools

Get started learning more about your health!

Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.

Symptom Checker

Feeling under the weather?

Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.

Connect With CentraCare