You are reading a NORD Rare Disease Report Abstract. NORD’s full collection of reports on over 1200 rare diseases is available to subscribers (click here for details). We are now also offering two full rare disease reports per day to visitors on our Web site.
NORD is very grateful to Joseph Kim, NORD Editorial Intern from the University of Notre Dame, and Connie TRM Schrander-Stumpel, MD, PhD, Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), MaastrichtUMC+, Maastricht, the Netherlands, for assistance in the preparation of this report.
Synonyms of L1 Syndrome
- HSAS, aqueductal stenosis, X-linked
- L1 disease
- L1 spectrum
- MASA syndrome
- SPG1 (X-linked complicated hereditary spastic paraplegia type 1)
- X-linked corpus callosum agenesis
- X-linked hydrocephalus with stenosis of the aqueduct of sylvius
- No subdivisions found.
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.
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.
L1 Syndrome Resources
(Please note that some of these organizations may provide information concerning certain conditions potentially associated with this disorder [e.g., mental retardation, aphasia, hydrocephalus, etc.].)
NORD Member Organizations:
(To become a member of NORD, an organization must meet established criteria and be approved by the NORD Board of Directors. If you're interested in becoming a member, please contact Susan Olivo, Membership Manager, at email@example.com.)
The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.
The National Organization for Rare Disorders (NORD) web site, its databases, and the contents thereof are copyrighted by NORD. No part of the NORD web site, databases, or the contents may be copied in any way, including but not limited to the following: electronically downloading, storing in a retrieval system, or redistributing for any commercial purposes without the express written permission of NORD. Permission is hereby granted to print one hard copy of the information on an individual disease for your personal use, provided that such content is in no way modified, and the credit for the source (NORD) and NORD’s copyright notice are included on the printed copy. Any other electronic reproduction or other printed versions is strictly prohibited.
Copyright 1997, 1998, 2005, 2012
NORD's Rare Disease Information Database is copyrighted and may not be published without the written consent of NORD.