Severe combined immunodeficiency (SCID), also known as bubble boy disease, is a genetic disorder where both the B cell and T cell arms of the immune system are impaired. There are several types of SCID resulting from defects in different genes. Symptoms include life-threatening infections from an early age. Treatment involves preventing infections, enzyme therapy, gene therapy, or bone marrow transplant from a matched or half-matched donor to rebuild the immune system. Transplants have been successful but carry risks, as seen in the original "bubble boy" who died from a virus in his transplanted marrow.

1. Severe Combined Immunodeficiency
(bubble boy disease)
Presented
By
SUBASH SAPKOTA

2. CONTENTS
Introduction
Types of SCID
Symptoms and diagnosis of
SCID
Treatment for SCID
Transplant for SCID
References

3. Introduction
 Severe combined immunodeficiency (SCID), is a
genetic disorder in which both "arms" (B cells and T
cells) of the adaptive immune system are impaired due to
a defect in one of several possible genes.
 SCID is a severe form of heritable immunodeficiency.
 It is also known as the bubble boy disease because its
victims are extremely vulnerable to infectious diseases
and some of them, such as David Vetter, become
famous for living in a sterile environment.
 SCID is the result of an immune system so highly
compromised that it is considered almost absent.

4. Types of SCID
 X-linked severe combined immunodeficiency
 Adenosine deaminase deficiency
 Omenn syndrome
 Bare lymphocyte syndrome
 JAK3
 Artemis/DCLRE1C

5. Symptoms and diagnosis of SCID
 Children with SCID are at risk for life-threatening
infections. From their first months of life, they have
infections that may be frequent, severe, long-lasting
or hard to treat. Infections may occur in the lungs
(pneumonia), around the brain and spinal cord
(meningitis) or in the blood stream.
 Several US states are performing pilot studies to
diagnose SCID in newborns through the use of T-
cell recombinant excision circles.
 The delay in detection is because newborns carry
their mother's antibodies for the first few weeks of
life and SCID babies look normal.

6. Treatment for SCID
 Preventing infections
 Enzyme therapy for ADA deficiency SCID
The standard treatment for ADA deficiency SCID is treatment with a
form of the ADA enzyme called PEG-ADA. Treatment with PEG-
ADA is effective in about 90% of children. However, despite PEG-
ADA therapy, some children continue to require IVIG treatments.
 Gene therapy
A treatment option being studied in clinical trials is gene therapy.
Gene therapy has shown promising results for some patients with
ADA deficiency SCID. At first, gene therapy also appeared to be a
promising treatment for X-linked SCID, but some children treated
with gene therapy developed leukemia. New trials of gene therapy
are in progress. But despite some promising results, gene therapy
remains an experimental treatment for SCID.

8. Transplant for SCID
 The most common treatment for SCID is bone marrow
transplantation, which has been successful using either a matched
related or unrelated donor, or a half-matched donor, who would be
either parent.
 The half-matched type of transplant is called haploidentical and was
perfected by Memorial Sloan Kettering Cancer Center in New York
and also Duke University Medical Center which currently does the
highest number of these transplants of any center in the world.
 Haploidentical bone marrow transplants require the donor marrow to
be depleted of all mature T cells to avoid the occurrence of graft-
versus-host disease (GVHD).
 Consequently, a functional immune system takes longer to develop
in a patient who receives a haploidentical bone marrow transplant
compared to a patient receiving a matched transplant.
 David Vetter, the original "bubble boy", had one of the first
transplantations but eventually died because of an unscreened virus,
Epstein-Barr (tests were not available at the time), in his newly
transplanted bone marrow from his sister.

10. References
http://www.cga.ct.gov/2008/rpt/2008-R-0564.htm
"Severe combined immunodeficiency: A national
surveillance study“
"Jak3, severe combined immunodeficiency, and a new class
of immunosuppressive drugs“
Fischer A, Hacein-Bey S, Cavazzana-Calvo M (2002). "Gene
therapy of severe combined immunodeficiencies". Nat Rev
Immunol 2 (8): 615-621.
Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L.
(2007). Dermatology: 2-Volume Set. St. Louis: Mosby.
ISBN 1-4160-2999-0

11. THANK YOU