Diagnostic outcomes of newborns referred from TREC-based NBS
| . | Total referred newborns (n = 130) . |
|---|---|
| SCID; genotype, n (%) | 7 (5.4%) |
| RAG1 | 3 |
| IL2RG | 2 |
| LIG4 | 1 |
| Unknown genetic cause | 1 |
| Non-SCID T cell impairment with genetic cause, n (%) | 38 (29.2%) |
| 22q11.2 deletion syndrome | 17 |
| Heterozygous FOXN1 variant | 6 |
| Trisomy 21 | 5 |
| Noonan syndrome | 5 |
| Ataxia telangiectasia | 2 |
| RMRP variant | 1 |
| RECQL4 variant | 1 |
| KMT2D variant | 1 |
| Reversible condition with T cell impairment, n (%) | 55 (42.3%) |
| Chylothorax and hydrops | 12 |
| (Severe) infections and sepsis | 10 |
| Maternal immunosuppressant use | 9 |
| Cardiac anomalies | 6 |
| Othera | 18 |
| Preterm and/or low birth weight alone, n (%) | 6 (4.6%) |
| Idiopathic T cell lymphopenia, n (%) | 12 (9.2%) |
| Inconclusiveb, n (%) | 3 (2.3%) |
| Normal T cell subsets without other cause for low TRECs, n (%) | 9 (6.9%) |
| . | Total referred newborns (n = 130) . |
|---|---|
| SCID; genotype, n (%) | 7 (5.4%) |
| RAG1 | 3 |
| IL2RG | 2 |
| LIG4 | 1 |
| Unknown genetic cause | 1 |
| Non-SCID T cell impairment with genetic cause, n (%) | 38 (29.2%) |
| 22q11.2 deletion syndrome | 17 |
| Heterozygous FOXN1 variant | 6 |
| Trisomy 21 | 5 |
| Noonan syndrome | 5 |
| Ataxia telangiectasia | 2 |
| RMRP variant | 1 |
| RECQL4 variant | 1 |
| KMT2D variant | 1 |
| Reversible condition with T cell impairment, n (%) | 55 (42.3%) |
| Chylothorax and hydrops | 12 |
| (Severe) infections and sepsis | 10 |
| Maternal immunosuppressant use | 9 |
| Cardiac anomalies | 6 |
| Othera | 18 |
| Preterm and/or low birth weight alone, n (%) | 6 (4.6%) |
| Idiopathic T cell lymphopenia, n (%) | 12 (9.2%) |
| Inconclusiveb, n (%) | 3 (2.3%) |
| Normal T cell subsets without other cause for low TRECs, n (%) | 9 (6.9%) |
Other reversible conditions included patient medication use such as corticosteroids or chemotherapy, congenital diaphragmatic hernia, asphyxia, and neonatal multimorbidity (Table S1).
Inconclusive diagnoses included one patient that got lost to follow-up and two patients in which parents refrained from either additional diagnostics or follow-up.