EARLY SIGNS
Babies with severe combined immunodeficiency (SCID) are more likely to develop life-threatening infections. This is why early screening and identification are so important.
Early signs of SCID include:
- High number of infections
- Infections that do not improve with antibiotic treatment for two or more months
- Diarrhea
- Poor weight gain or growth (failure to thrive)
- Thrush (a fungal infection) in the mouth or throat that does not go away
If your baby shows any of these signs, be sure to contact your baby’s doctor immediately.
CAUSES
Our immune systems are made up of special cells and proteins that protect us from germs and other things in our environment that can cause illnesses and infections. Specifically, T-cells and B-cells are types of white blood cells that are very important to our immune system.
If your baby has severe combined immunodeficiency (SCID), then his or her body either does not make enough or makes non-working T and B-cells. Without these working cells, the immune system cannot work correctly. This is why infants with SCID are more likely to catch serious infections and illnesses.
There are many different genetic causes of SCID. SCID may be inherited from parents or can be the result of a new genetic change in the child. All known forms of SCID follow either an autosomal recessive or an X-linked recessive pattern of inheritance.
When SCID is an autosomal recessive genetic condition, a child must inherit two copies of the non-working gene, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with SCID is rare, when both parents are carriers, they can have more than one child with the condition.
When SCID is an X-linked recessive genetic condition, a male must inherit one copy of the non-working gene from his mother to have the condition. A female must inherit two copies of the non-working gene, one from each parent, in order to have the condition. In X-linked conditions, the gene is carried on the X sex chromosome; therefore, the condition affects males more than females. While having a child with SCID is rare, when one or both parents carry the non-working gene, they can have more than one child with the condition.
TREATMENT
Isolation
Your baby may need to stay away from young children. This makes it less likely he or she will catch an illness from another child.
Immunoglobulin Replacement Therapy
Babies with SCID should be placed on immunoglobulin replacement therapy if they are more than three months of age or have already had infections. Regular immunoglobulin replacement therapy can replace missing antibodies that help your baby fight infections.
Bone Marrow Transplant
The most effective treatment for SCID is a bone marrow transplant. Bone marrow makes cells for fighting infections and illnesses. In a bone marrow transplant, bone marrow cells from a person with a working immune system are given to a person with SCID, whose bone marrow cannot make cells to fight infections and illnesses.
EXPECTED OUTCOMES
With early screening and treatment, babies with severe combined immunodeficiency (SCID) are less likely to develop life-threatening illnesses and infections. Children who receive bone marrow transplants often lead healthy lives.
If left untreated, babies with SCID can develop serious and fatal infections. Children with SCID who do not receive early treatment rarely live past two years of age.