Severe Combined Immunodeficiency

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Severe Combined Immunodeficiency 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.


  • Bubble Boy Syndrome
  • SCID

Disorder Subdivisions

  • None

General Discussion

Severe Combined Immunodeficiency (SCID) is a group of rare congenital syndromes characterized by little if any immune responses. This results in frequent recurring infections. Cellular immune responses involve specialized white blood cells known as T lymphocytes or "killer cells". These cells assist other white blood cells (B lymphocytes) to respond to infectious, foreign agents that invade the body (i.e., bacteria or viruses). The B lymphocytes maintain immunity by enabling the body to produce and preserve circulating antibodies.

People with Severe Combined Immunodeficiency are unusually susceptible to recurrent infections with bacteria, viruses, fungi, and other infectious agents that can be life-threatening.

There are several types of Severe Combined Immunodeficiencies. These include: Autosomal Recessive Severe Combined Immunodeficiency, X-Linked Recessive Severe Combined Immunodeficiency, Adenosine Deaminase Deficiency (ADA), Bare Lymphocyte Syndrome, Severe Combined Immunodeficiency with Leukopenia (Reticular Dysgenesis), and Swiss-type Agammaglobulinemia. Each type of Severe Combined Immune Deficiency is caused by a different genetic defect, but the primary symptom is reduced or absent immune functions, and all types are hereditary.

Supporting Organizations

American Academy of Allergy, Asthma and Immunology

611 East Wells Street
Milwaukee, WI 53202
Tel: (414)272-6071
Fax: (414)276-3349
Tel: (800)822-2762

European Society for Immunodeficiencies

1-3 rue de Chantepoulet
Geneva, CH 1211
Tel: 410229080484
Fax: 41229069140

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

Immune Deficiency Foundation

110 West Road
Suite 300
Towson, MD 21204
Tel: (410)321-6647
Fax: (410)321-9165
Tel: (800)296-4433

International Patient Organization for Primary Immunodeficiencies

Firside Main Road
Cornwall, PL11 3LE
United Kingdom
Tel: 441503250668
Fax: 441503250961

March of Dimes Birth Defects Foundation

1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)997-4488
Fax: (914)997-4763

NIH/National Institute of Allergy and Infectious Diseases

NIAID Office of Communications and Government Relations
5601 Fishers Lane, MSC 9806
Bethesda, MD 20892-9806
Tel: (301)496-5717
Fax: (301)402-3573
Tel: (866)284-4107

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 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 or email

Last Updated:  12/13/1969
Copyright  2007 National Organization for Rare Disorders, Inc.