L1 Syndrome

National Organization for Rare Disorders, Inc.

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Important
It is possible that the main title of the report L1 Syndrome is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Summary
L1 syndrome is an inherited, X-linked disorder occurring in males that primarily affects the nervous system. The disease is mainly characterized by hydrocephalus (increased fluid in the center of the brain), spasticity of the lower limbs (muscle stiffness), adducted thumbs (clasped towards the palm), aphasia (difficulty with speaking), seizures, and agenesis of the corpus callosum (underdeveloped or absent connecting tissue between the left and right hemispheres of the brain). Affected individuals have intellectual disability in the mild to moderate range. L1 syndrome is caused by abnormalities (mutations) in the L1CAM gene, which affects about 1 in 30,000 males.

Introduction
The acronym CRASH (corpus callosum hypoplasia, retardation, adducted thumbs, spastic paraparesis and hydrocephalus) syndrome was originally proposed in 1995 by Dr. Erik Fransen to describe L1 syndrome but is no longer used.

Supporting Organizations

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
Website: http://rarediseases.info.nih.gov/GARD/

Hydrocephalus Association

4340 East West Highway Ste 950
Bethesda, MD 20814
USA
Tel: (301)202-3811
Fax: (301)202-3813
Tel: (888)598-3789
Email: info@hydroassoc.org
Website: http://www.hydroassoc.org

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
Website: http://www.ninds.nih.gov/

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
Email: nidcdinfo@nidcd.nih.gov
Website: http://www.nidcd.nih.gov

National Aphasia Association

350 Seventh Avenue
Suite 902
New York, NY 10007
USA
Tel: (212)267-2814
Fax: (212)267-2812
Tel: (800)922-4622
Email: responsecenter@aphasia.org
Website: http://www.aphasia.org

National Hydrocephalus Foundation

12413 Centralia Rd.
Lakewood, CA 90715-1653
USA
Tel: (562)924-6666
Fax: (562)924-6666
Tel: (888)857-3434
Email: nhf@earthlink.net
Website: http://www.nhfonline.org

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, 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.

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.

Last Updated:  5/21/2015
Copyright  2015 National Organization for Rare Disorders, Inc.