What Is SCID?
What does the acronym SCID stand for?
Severe Combined Immunodeficiency
SCID symptoms usually begin at what stage of life?
Infancy (within the first few months of life)
Is SCID caused by bacteria, viruses, or genetic mutations?
Genetic mutations
In which decades did the world first learn about SCID?
1970s–1980s
What treatment first proved SCID could be cured in 1968?
Hematopoietic stem cell transplantation (HSCT)
SCID is a disorder that affects which part of the body?
Name one common infection seen in babies with SCID.
Pneumonia, chronic diarrhea, thrush, or ear infections
What immune cell type is most severely affected in SCID?
T cells
Which two U.S. states began SCID newborn screening in 2008?
Wisconsin and Massachusetts
What does HSCT stand for?
Hematopoietic stem cell transplantation
SCID is caused by defects in which types of immune cells?
T cells and B cells
Why do infants with SCID often fail to gain weight and grow normally?
Recurrent infections and poor nutrient absorption due to immune failure
Which type of SCID is linked to the X chromosome?
X-linked SCID
What major announcement did HHS make on May 21, 2010?
Adding SCID to the Recommended Uniform Screening Panel (RUSP)
Why was PEG-ADA introduced in the 1990s?
To stabilize ADA-SCID patients by replacing the missing enzyme
Is SCID considered inherited or acquired?
Inherited (genetic)
Why are routine infections dangerous for people with SCID?
The immune system cannot fight even mild infections
How does ADA deficiency cause SCID?
Toxic metabolite buildup that destroys developing lymphocytes
By what year were all 50 U.S. states screening newborns for SCID?
2018
What serious complication temporarily halted early gene therapy trials?
Leukemia caused by insertional mutagenesis
Why is SCID often described as a “medical emergency” in infants?
Because infants lack an immune defense and can die from common infections without early treatment
Why are live vaccines dangerous or fatal for infants with SCID?
Live vaccines can cause actual infections in immunodeficient patients
Why does the exact genetic mutation matter for choosing treatment?
Different mutations respond best to different treatments like HSCT or gene therapy
As of 2025, how many countries worldwide screen for SCID?
23 countries
Why is HSCT still considered the “gold standard” treatment for SCID?
It offers the highest long-term survival and complete immune reconstitution