Non–SCID conditions that may lead to an abnormal T-cell receptor excision circle–based newborn screen for SCID10, 23, 31–36
| Non-SCID causes of T-cell lymphopenia | Examples |
|---|---|
| Syndromic disorders and congenital abnormalities | Trisomy 18 |
| Trisomy 21 | |
| DiGeorge syndrome | |
| CHARGE syndrome | |
| Ataxia–Telangiectasia syndrome | |
| Secondary T-cell lymphopenia | Cardiac or gastrointestinal anomalies |
| Multiple congenital anomalies | |
| Neonatal leukemia | |
| T-cells losses into third space (e.g., hydrops or vascular leakage) | |
| Prenatal exposure to purine antagonists | |
| Preterm birth | |
| Idiopathic T-cell lymphopenia | |
| Combined immunodeficiencies with dysfunctional T cells | DOCK8 deficiency |
| Wiskott–Aldrich Syndrome |
Note: SCID = severe combined immunodeficiency.