Newborn Screening For Severe Combined Immunodeficiency

Newborn screening (NBS) is a nationwide program to find babies born with certain health conditions, including SCID. While diagnostic testing should be used to rule out or confirm a SCID diagnosis, NBS can help you and your health care providers take immediate steps in order to keep your child as healthy as possible. The Secretary of the U.S. Department of Health and Human Services added screening for SCID to the Recommended Uniform Screening Panel (RUSP) in May 2010. Nevada State Public Health Laboratory was awarded a two- year CDC grant to start SCID testing that is projected to go live on January 29, 2018.

The Importance of Early Diagnosis in SCID

Infants with SCID are at risk for fatal infections the moment they are born. Therefore, early diagnosis and treatment are very important. For example, infants with SCID who are treated with BMT before 3.5 months old have a 95% chance of long- term survival and of living a healthy life. BMT treatment after 3.5 months old leads to a 60-70% chance of long-term survival. With early detection and treatment, patients with SCID are more likely to live healthy lives.

How is Newborn Screening Done?

Newborn screening is done during the first few days of your baby's life—usually by a health care provider in the hospital. A few drops of blood from a heel prick are placed on a special card, called a Guthrie card. This card with your baby's information is mailed to a special state laboratory that will test the blood sample for certain health conditions, including SCID. In Nevada, newborn screening involves two blood samples, first one between 24-48 hours of age and second one between 10-14 days of age.

Newborn screening detects SCID by looking for T cell receptor excision circles or TRECs for short TRECs are found in every healthy newborn’s blood. They are present when T cells are being produced. Since babies with SCID have few to no T cells, they also have few to no TRECs in their blood.

Without newborn screening, the diagnosis of SCID is usually based on history of infections, tests on blood lymphocytes and gene sequence analysis. In only about 20% of cases is a family history of SCID available.

Understanding NBS Test Results

If a baby has a positive result on the initial SCID screen, it does not yet mean that he or she has SCID. Prematurity, other less severe immune disorders or other syndromes can also cause low levels of TRECs in the blood. It is also possible for a baby to have a positive screening result, but have a normal immune system. Therefore, a positive screening result means that further testing must be done to confirm or rule out SCID.

When a parent or both parents are known to be carriers of SCID, newborn screening results are not enough to rule out SCID in a newborn baby. In this case, diagnostic testing should be done, as well as newborn screening.

Visit the following websites for more information:


Pediatric Immunologists
Nevin Wilson, MD
UNLV Pediatric Center
1524 Pinto Lane 2nd Floor
Las Vegas, NV 89106
Phone:(702) 992-6834
Fax:(702) 671-2233
Cell: (775) 815-8269

Mary Beth Hogan, MD
UNLV Pediatric Center
1524 Pinto Lane 2nd Floor
Las Vegas, NV 89106
Phone: (702) 992-6834
Fax: (702) 671-2233