Adenosine Deaminase Deficiency
What is Adenosine Deaminase Deficiency?
Adenosine deaminase deficiency (ADA-SCID) is a rare, inherited disorder in which a malfunctioning enzyme prevents red blood cells from developing normally. Without the enzyme, the body has difficulty fighting infections, and some individuals may even develop other medical problems. ADA-SCID is also referred to as “bubble boy disease” because affected individuals can become so ill from infection that the only way to protect them is to place them in a sterile, germ-free environment.
Symptoms of Adenosine Deaminase Deficiency
The symptoms of ADA-SCID generally begin in infancy and may include:
- Recurrent, severe infections requiring hospitalization
- Low levels of blood cells called lymphocytes
- Slow growth
- Severe diarrhea
- Trouble gaining weight
- Low resistance to infection
- Pneumonia
Diagnosis of Adenosine Deaminase Deficiency
ADA-SCID can be detected through a variety of tests. The most common test is a blood test that looks for low levels of an enzyme called adenosine deaminase. Other tests include genetic testing, a clotting test, and a lymphocyte count. If the disease is suspected, a skin or muscle biopsy may be ordered.
Treatment of Adenosine Deaminase Deficiency
The primary treatment for ADA-SCID is a bone marrow or stem cell transplant. During the procedure, healthy stem cells are transplanted into the body to replace the affected cells. A course of immunoglobulin therapy may also be prescribed to help the body fight infections. This therapy consists of a series of injections of a concentrated, sterile solution of antibodies that helps to boost the body's immune system.
Prevention of Adenosine Deaminase Deficiency
Adenosine deaminase deficiency can be prevented by screening for the disorder before a baby is born. Prenatal testing is available to determine if a fetus is affected. This is usually done in families with a history of ADA-SCID or other genetic disorders. In addition, couples considering having a baby should have genetic testing done before conception to identify any potential genetic disorders.