Adenosine Deaminase Severe Combined Immunodeficiency (ADA-SCID)

When you have a severe combined immunodeficiency (SCID), your immune system can't fight off even mild infections on its own.

With adenosine deaminase severe combined immunodeficiency (ADA-SCID), your body's defenses stop working because of a problem with your genes.

ADA-SCID is a serious disease that usually shows up early in life. Treatments can help, though, and people who get treatment before an infection happens can live long, healthy lives.

Everyone has ADA genes. If you have ADA deficiency, you have a glitch (mutation) in yours. As a result, your body doesn't make enough of a certain tool, called an enzyme, that helps your white blood cells protect you from getting sick. Without that protection, you can easily get infections.

If your child is born with ADA deficiency, they'll probably get a SCID diagnosis by the time he’s 6 months old. If the disease starts later, the symptoms may be less severe.

With treatment, you can manage symptoms and avoid infections. Left untreated, the body becomes less and less able to fight infections, which can be life-threatening.

Symptoms

Symptoms usually appear in the first months of life. If your baby has this disease, they may have a lot of infections in different parts of their body, including:

• Ear
• Sinus
• Mouth
• Lung
• Skin

It’s common for babies to get infections. Pay special attention if your child has them often and they:

• Are severe
• Are long-lasting
• Are unusual
• Frequently recur

Children with ADA-SCID often have diarrhea and widespread skin rashes. They may also grow slowly and have delayed progress in other development areas like motor and social skills.

If the disease doesn’t appear until later in childhood or adulthood, the symptoms may be mild at first. The first symptoms may be ear or upper-respiratory infections that keep coming back.

Getting a Diagnosis

Your chances of living well are best with early diagnosis and treatment.

Some states screen all newborns for ADA-SCID, and many experts say early testing should be required in all states. You can be checked at any age. A doctor will take a blood sample and test it to see if the immune system is working right.

Sometimes the doctor needs to do more than one blood test to diagnose ADA-SCID.

Your doctor will want to know:

• What kind of infections have you (or your child) had?
• How long did they last?
• Did they go away after treatment?
• Did they come back?
• Does anyone else in your family have immune system problems?
• Has anyone in the family had genetic testing?

If you find out you or your child has ADA-SCID, your doctor may talk with you about genetic counseling and early blood testing of all your children.