Causes of Severe Combined Immunodeficiency

Causes

SCID is caused by defects in different genes involved in the development and function of infection-fighting immune cells. More than a dozen genes have been implicated in SCID, but gene defects are unknown in approximately 15 percent of newborn-screened SCID infants.

Source: NIAID (NIH)1

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Back to: « Severe Combined Immunodeficiency

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Severe Combined Immunodeficiency (SCID) Causes

SCID is caused by defects in different genes involved in the development and function of infection-fighting immune cells. More than a dozen genes have been implicated in SCID, but gene defects are unknown in approximately 15 percent of newborn-screened SCID infants, according to an NIH-funded study.

Most often, SCID is inherited in an autosomal recessive pattern, in which both copies of a particular gene—one inherited from the mother and one from the father—contain defects. The best-known form of autosomal recessive SCID is caused by adenosine deaminase (ADA) deficiency, in which infants lack the ADA enzyme necessary for T-cell survival.

X-linked SCID, which is caused by mutations in a gene on the X chromosome, primarily affects male infants. Boys with this type of SCID have lymphocytes that grow and develop abnormally. As a consequence, they have low numbers of T cells and natural killer cells, and their B cells do not function.

Source: NIAID (NIH)2

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Caused by defects in any of several possible genes, SCID makes those affected highly susceptible to life-threatening infections by viruses, bacteria and fungi.

Source: NHGRI (NIH)3

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In severe combined immunodeficiency, lack of an enzyme means that toxic waste builds up inside immune system cells, killing them and thus devastating the immune system.

Source: NCBI, Genes and Disease (NCBI/NIH)4

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The defining feature of SCID, commonly known as "bubble boy" disease, is a defect in the specialized white blood cells (B- and T-lymphocytes) that defend us from infection by viruses, bacteria and fungi.

Source: NCBI, Genes and Disease (NCBI/NIH)5

Causes of Severe Combined Immunodeficiency

Causes of the condition may include:6 Causes of Severe Combined Immunodeficiency:

Causes List for Severe Combined Immunodeficiency

Some of the possible causes of Severe Combined Immunodeficiency or similar disorders may include:7

... Full Causes List for Severe Combined Immunodeficiency »

Genetics of Severe Combined Immunodeficiency

More than 80 percent of SCID infants do not have a family history of the condition. ...Source: NIAID (NIH)8 ...

... More on Genetics »

Causes

See also cause information for related diseases:



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References

  1. Source: NIAID (NIH): niaid.nih.gov/ diseases-conditions/ severe-combined-immunodeficiency-scid
  2. Source: NIAID (NIH): niaid.nih.gov/ diseases-conditions/ scid-causes
  3. Source: NHGRI (NIH): genome.gov/ 13014325/ learning-about-severe-combined-immunodeficiency-scid/ 
  4. Source: NCBI, Genes and Disease (NCBI/NIH): ncbi.nlm.nih.gov/ books/ NBK22243/ 
  5. Source: NCBI, Genes and Disease (NCBI/NIH): ncbi.nlm.nih.gov/ books/ NBK22254/ 
  6. Source: Human Phenotype Ontology
  7. Source: Algorithmically Generated List
  8. Source: NIAID (NIH): niaid.nih.gov/ diseases-conditions/ severe-combined-immunodeficiency-scid

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