Positive Newborn Screen

QUESTION: Why is the Newborn Screening test for SCID called a TREC test?

ANSWER: The Newborn Screening test measures the number of T cell receptor excision circles (TRECs) found in a spot of blood taken from the baby’s heel. The number of TRECs indicates how many T cells the baby has. 

Negative vs Positive Result:
A Negative result indicates normal TREC levels.

A Positive test indicates low TREC levels. In this case, further testing is needed to see if the baby has a condition affecting their T cells.

Has your baby’s newborn screen test been positive for TRECs? Low levels of TRECs may stem from various factors like prematurity, congenital athymia, other congenital abnormalities associated with low T-cells, Combined Immunodeficiency, Secondary loss of T-cells, or SCID. SCID is only one possibility, but it is important to follow up quickly and determine if SCID is the cause.

Download the pamphlet below: “Low T Cell Results” for more information. 

If you’re ready to learn more about SCID Types and Treatments download the file SCID Types

If your baby has already been diagnosed with SCID go to our section for SCID Diagnosis and follow the link in the menu to Connect with Community.