Werdnig Hoffman Disease

Important
It is possible that the main title of the report Werdnig Hoffman Disease 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

Infantile Spinal Muscular Atrophy
SMA 1
SMA, Infantile Acute Form
Spinal Muscular Atrophy Type 1
Werdnig-Hoffman Paralysis

Disorder Subdivisions

None

General Discussion

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weakness of the truncal, and extremity muscles initially, followed by chewing, swallowing and breathing difficulties. Motor neurons are nerve cells that transmit nerve impulses from the spinal cord or brain (central nervous system) to muscle or glandular tissue.

Approximately 80 percent of individuals with SMA fall into the severe category (Werdnig-Hoffman disease or SMA1). Infants with SMA1 experience severe weakness before 6 months of age, and the patient never achieves the ability to sit independently when placed. Muscle weakness, lack of motor development and poor muscle tone are the major clinical manifestations of SMA1. Infants with the gravest prognosis have problems sucking or swallowing. Some show abdominal breathing in the first few months of life. Abdominal breathing is noted when the abdomen protrudes during inspiration. Normally, the chest expands during inspiration as the intercostal muscles (the muscles between the ribs) expand during inspiration. Abdominal breathing occurs when the intercostal muscles are weak and the diaphragm muscle is responsible for inspiration. Movement of the diaphragm (the muscle between the chest and abdomen) expands causing the abdomen to move during the inspiration cycle. A twitching of the tongue is often seen. Cognitive development is normal. Most affected children die before 2 years of age but survival may be dependent on the degree of respiratory function and respiratory support.

The different subtypes, SMA 0-4 are based on the age of onset of symptoms and the course and progression of the disease. SMA represents a continuum or spectrum of disease with a mild end and a severe end. SMA0 patients are extremely weak a birth, require immediate artificial ventilation and will never breathe independently. Werdnig-Hoffman disease, which is also known as spinal muscular atrophy type 1 (SMA1) or acute spinal muscular atrophy, refers to individuals who have symptom onset prior to 6 months of age. SMA 2 patients will show symptoms prior to age 1 year, will sit but never walk. SMA 3 patients (Kugelberg-Welander disease) will show symptoms after age 1, and will walk for a period of time prior to loss of motor abilities. SMA 4 patients will not develop symptoms much before age 10 years.

All the SMAs are inherited as an autosomal recessive trait. Molecular genetic testing has revealed that all types of autosomal recessive SMA are caused by disruptions or errors (mutations) in the SMN1 (survival motor neuron 1) gene on chromosome 5

Resources

March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)428-7100
Fax: (914)997-4763
Tel: (888)663-4637
Email: Askus@marchofdimes.com
Internet: http://www.marchofdimes.com

Families of Spinal Muscular Atrophy
P.O. Box 196
Libertyville, IL 60048
Tel: (847)367-7620
Fax: (847)367-7623
Tel: (800)886-1762
Email: sma@fsma.org
Internet: http://www.curesma.com

Muscular Dystrophy Association
3300 E. Sunrise Dr
Tucson, AZ 85718
USA
Tel: 5205292000
Fax: 5205295300
Tel: 8003444863
Email: mda@mdausa.org
Internet: http://www.mdausa.org

Muscular Dystrophy Campaign
7-11 Prescott Place
London, SW4 6BS
United Kingdom
Email: info@muscular-dystrophy.org
Internet: http://www.muscular-dystrophy.org

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/

Jennifer Trust for Spinal Muscular Atrophy
Elta House
Birmingham Road
Stratford-upon-Avon
Warwickshire, CV37 0AQ
United Kingdom
Tel: 0870 7743651
Fax: 0870 7743652
Email: jennifer@jtsma.org.uk
Internet: http://www.jtsma.org.uk

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: 2/5/2008
Copyright 1985, 1986, 1987, 1988, 1989, 1992, 1994, 1995, 1997, 1999, 2000, 2003, 2007, 2008 National Organization for Rare Disorders, Inc.

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