Under the implementation of the “Advanced neonatal screening” Federal Program and the Ministry of Healthcare of Russia Order No. 274n “On approval of the Procedure for providing medical care to patients with congenital and/or hereditary diseases” that started jointly on Jan. 01, 2023 overall Russia, the examination of all newborns for the 29 nosologies of exchange disorders by tandem mass spectrometry as well as spinal muscular atrophy and primary immunodeficiencies by polymerase chain reaction had begun. Circa 1 million and 230 thousand newborns were examined in 85 Russia regions during 2023 with the level of births coverage exceeding 98%. As a result, a risk group that amounted to 1.86% of all examined was formed with confirming diagnostics performed for 8712 neonatal patients at risk, of which 676 have had their deceases confirmed including 379 hereditary metabolic diseases, 117 spinal muscular atrophies and 180 primary immunodeficiencies. Effective treatment and dispensary follow-up methods have been developed so far for all the screened nosologies. Thus, the introduction of the neonatal screening made it possible to initiate therapy for most of the identified patients at preclinical stages reducing the overall infant mortality and improving the quality of life for such patients and their caretakers.

The expanded newborn screening (NBS) program in the Russian Federation was initiated in 2023, among which severe combined immunodeficiency (SCID) is screened using TREC/KREC assays. Here, we report a rare case of a TP63-associated disease identified through this NBS program. Dried blood spots from newborns were initially screened for TREC/KREC levels, and those with values below the cut-off underwent confirmatory testing and further genetic analysis, including whole-exome sequencing (WES). A male newborn was identified with significantly reduced TREC values, indicative of T cell lymphopenia. Genetic analysis revealed a heterozygous NM_003722.5:c.1027C>T variant in TP63, leading to the p.(Arg343Trp) substitution within the DNA binding domain. This mutation has been previously associated with Ectrodactyly–Ectodermal Dysplasia–Cleft lip/palate syndrome (EEC) syndrome and shown to reduce the transactivation activity of TP63 in a dominant-negative manner. This case represents one of the few instances of immune system involvement in a patient with a TP63 mutation, highlighting the need for further investigation into the immunological aspects of TP63-associated disorders. Our findings suggest that comprehensive immunological evaluation should be considered for patients with TP63 mutations to better understand and manage potential immune dysfunctions.

The expanded newborn screening (NBS) program in the Russian Federation, launched in 2023, includes the detection of severe forms of T- and B-cell immunodeficiencies via TREC/KREC quantification. We report a rare case of a male infant having multiple congenital anomalies and lymphopenia identified through this program. Genetic testing revealed a 25.8 Mb terminal deletion spanning 13q31.2–qter, consistent with 13q deletion syndrome. Initial NBS revealed reduced TREC levels, prompting further evaluation. The patient exhibited a complex phenotype, including central nervous system malformation (alobar holoprosencephaly), severe congenital heart disease, renal hypoplasia, limb and genitourinary anomalies, and facial dysmorphism. Postnatal complications included pneumonia, pleuritis, and chylothorax. Flow cytometry demonstrated mild T- and B-cell lymphopenia. The genomic defect was characterized using long-read third-generation sequencing, enabling precise breakpoint identification and accurate mapping of deleted genes. The deletion was confirmed via subtelomeric FISH analysis. The patient died at 7 months of age due to the progression of underlying congenital anomalies and associated complications. Our findings broaden the clinical characterization of distal 13q deletion syndrome and demonstrate the value of long-read sequencing in structural chromosomal analysis. They further highlight the difficulties of caring for neonates having complex malformations and immune dysfunction. Given the potential for both primary and secondary immune disturbances, comprehensive immunological evaluation should be considered in patients having 13q deletion syndrome to improve diagnostic accuracy and inform appropriate clinical management.

Background: Newborn screening (NBS) for severe combined immunodeficiency (SCID) relies on the measurement of T‐cell receptor excision circle (TREC) for early diagnosis and intervention. However, considerable variation in TREC cutoff values across countries and testing platforms poses challenges for standardization and optimal screening performance. This study aimed to refine the TREC cutoff values in a large Russian pilot NBS cohort comprising 202,908 newborns, with a primary focus on improving SCID detection sensitivity.Methods: A retrospective analysis of 202,908 newborns from a pilot NBS project assessed TREC and KREC levels. Confirmed PID diagnoses were compared with TREC measurements in a group of 66 false‐positive cases. The optimal TREC cutoff was established using ROC analysis, with validation across patients with SCID, 22q11.2 deletion syndrome (22q11.2DS), and syndromic forms of PID from an extended validation cohort of PID patients from the Dmitry Rogachev National Medical Research Center.Results: Receiver operating characteristic (ROC) analysis based on true‐positive cases identified an optimal TREC cutoff of 150 copies/10⁵ cells. Values between 150–200 copies/10⁵ cells were found to identify high‐risk newborns who require closer monitoring. This threshold was validated in an independent cohort, reducing missed SCID cases while improving the detection of 22q11.2 deletion syndrome and other syndromic primary immunodeficiencies (PIDs). Notably, elevated TREC levels in some SCID patients reflected “leaky” SCID phenotypes, which nonetheless required curative intervention. Additionally, syndromic PIDs and cases of transient idiopathic lymphopenia (TIL) were also more accurately identified, enabling timely clinical management.Conclusion: These findings emphasize the need for broader evaluation of TREC cutoff values across diverse assay systems to improve the effectiveness, comparability, and global harmonization of NBS programs.

Expanded neonatal screening (ENS) system is a crucial invention that was aimed at reducing infant mortality by enabling the early detection and treatment of severe and life-threatening conditions. Since its Russia-wide implementation in 2023 ENS had successfully identified hundreds of cases of newborns at risk allowing further timely medical intervention that often happened even at a pre-symptomatic stage. However, further optimization of patient routing algorithms within ENS is necessary in order to enhance the identification of newborns at risk and expedite their diagnosis and treatment. This manuscript focuses on optimizing of the routing algorithms specifically for newborns with suspected adenosine deaminase (ADA) deficiency, a severe form of primary immunodeficiency. Given the unique therapeutic and preventive measures required for these patients, the proposed guidelines expand the criteria for referring newborns for confirmatory diagnostics based on nucleoside metabolism data obtained from tandem mass spectrometry of dried blood spots. These improvements are aimed to the earliest detection and targeted treatment of newborns with ADA deficiency thereby enhancing the overall efficiency of primary immunodeficiency screening in Russia.