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Severe Combined Immunodeficiency (SCID)

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Severe Combined Immunodeficiency (SCID) in children is a critical condition as they are born with very little or no immune system, which makes them extremely susceptible to infections. These can be common illnesses such as chickenpox, pneumonia, and meningitis that, in the absence of a functioning immune system, can be fatal. Children with SCID appear healthy at birth but if left untreated, the disease can result in death within the first year of life due to the inability to fight off infections.

Causes: Severe Combined Immunodeficiency (SCID) is caused by mutations in various genes that are crucial for the development and function of T cells and B cells, which are the immune system’s primary defense against infections. These mutations lead to the absence or malfunctioning of these immune cells, leaving the body vulnerable to infections​​.

Symptoms: Children with SCID typically appear healthy at birth but within the first few months, they begin to exhibit severe and recurrent infections. The infections can be bacterial, viral, fungal, or protozoal, and they tend to be more severe than those experienced by children with a normal immune system. Common infections include pneumonia, meningitis, and bloodstream infections. Failure to thrive and chronic diarrhea may also be symptoms of SCID​​.

Treatment: The mainstay of treatment for SCID is a bone marrow transplant (BMT), also known as a hematopoietic stem cell transplant. This procedure replaces the defective immune system with a healthy one from a donor. Early diagnosis and treatment, before the child contracts any serious infections, are crucial for the success of BMT.

In addition to BMT, gene therapy may be an option for certain types of SCID. This involves inserting a normal copy of the gene that is defective in SCID into the child’s own bone marrow cells.

Enzyme replacement therapy is another treatment for a specific type of SCID known as adenosine deaminase deficiency (ADA-SCID).

Prophylactic antibiotics and antifungals can be used to prevent infections, and immunoglobulin replacement therapy can help provide temporary immune protection​​.

Isolation measures are often necessary to protect these children from pathogens until their immune system can be restored through treatment.

The Pediatric.me content is provided for informational purposes only and is not intended as medical advice or as a substitute for medical advice of a physician