Article The successful inclusion of ADA SCID in Tuscany expanded newborn screening program was published on May 5, 2021 in the journal Clinical Chemistry and Laboratory Medicine (CCLM) (volume 0, issue 0).

Metachromatic leukodystrophy (MLD) is a rare inherited disorder of lysosomal storage, caused by a deficiency in the arylsulfatase A (ARSA) enzyme, leading to toxic accumulation of sulfatides, which progressively impair motor and cognitive function. MLD is a candidate for inclusion in newborn screening (NBS) programs, due to the narrow pre-symptomatic window for effective therapeutic intervention. We set up a prospective pilot NBS program for MLD in Tuscany, based on a two-step approach. The first-tier test quantified four sulfatides; if levels exceeded the cut-off, we performed the second-tier test by measuring ARSA activity on the same neonatal dried blood spot (DBS). We performed the first-tier test on 42,262 newborns over two years and the second-tier test on residual neonatal DBS from 90 of them (0.21%). We recalled 10 newborns (0.02%) for an additional DBS, due to insufficient residual material for a second-tier test (n = 4) or to low ARSA activity (n = 6). We found normal ARSA activity in all new DBS and identified no new cases of MLD. Retrospective analysis of eight neonatal and fifteen non-neonatal DBS from patients with genetically confirmed MLD showed that the algorithm accurately identified MLD patients. This diagnostic algorithm proved feasible and accurate for early detection of MLD in prospective NBS.

Objectives: Pyridoxine-dependent epilepsy (PDE) is a rare genetic disorder characterized by intractable neonatal seizures responsive to pyridoxine. Diagnosis relies on quantification of α-aminoadipic semialdehyde, piperideine-6-carboxylate and pipecolic acid in urine or plasma in patients with overt symptoms. We developed and validated simple and rapid first- and second-tier methods for two recently published biomarkers of PDE (2S,6S-/2S,6R-oxopropylpiperidine-2-carboxylic acid (2-OPP) and 6-oxopiperidine-2-carboxylic acid (6-oxoPIP)) in extended newborn screening (NBS) programs from neonatal dried blood spots (DBS). Methods: For the first-line test, DBS specimens were collected from 5,405 newborns who underwent routine NBS and analysed by FIA-MS/MS. For the second-tier test, samples were analysed by LC-MS/MS. The neonatal DBS from two patients with genetically confirmed PDE were also analysed. Results: The reference values for NBS resulted <0.34 μmol/L for 2-OPP and <4.51 μmol/L for 6-oxoPIP. In the second-tier test, limits of detection were 0.07 μmol/L and 0.14 μmol/L, whereas limits of quantification were 0.25 μmol/L and 0.48 μmol/L, respectively, for 2-OPP and for 6-oxoPIP. The tests provided good linearity, reproducibility, accuracy and precision, with acceptable matrix effect and carry-over, according to international validation criteria. The biomarkers in DBS were stable at room temperature, +4 °C and −20 °C for one month. When assessing these biomarkers in two patients with genetically confirmed PDE, the higher sensitivity of 2-OPP as compared to 6-oxoPIP in discriminating PDE emerged. Conclusions: The first-line and second-tier tests developed in this study highlight the potential for including PDE in the NBS panel, early diagnosis and prompt precision treatment initiation.

Ukraine’s healthcare system has shown remarkable resilience in continuing newborn screening (NBS), beyond the challenges of war. Amid the conflict, a Ukrainian newborn screened positive for an extremely rare severe combined immunodeficiency (SCID)–purine nucleoside phosphorylase (PNP) deficiency. Ukraine successfully carried out NBS on a neonatal dried blood spot (DBS) by real-time PCR, which showed remarkably reduced T-cell receptor and kappa-deleting recombination excision circles (TREC/KREC). Retesting was delayed due to communication difficulties with the family. Whole exome sequencing on a new DBS confirmed the diagnosis. The newborn was a candidate for allogeneic hematopoietic stem cell transplantation (HSCT), the only curative treatment. HSCT is a complex procedure still ongoing in Ukraine despite the conflict. However, due to the psychosocial strain, the family sought medical support in Germany, where HSCT was performed successfully at 6 months. As part of a collaborative initiative with Italy, PNP biomarkers were quantified on the same DBSs using tandem mass spectrometry, according to the protocols established for SCID NBS in Tuscany, serving as a proof of concept of its diagnostic performance. This case highlights the importance of sustaining preventive and life-saving healthcare services, and reflects the key role of international partnerships in upholding the right to healthcare in times of crisis.

Ukraine’s healthcare system shows remarkable resilience in continuing newborn screening (NBS) program, beyond war challenges. Amid the conflict, a Ukrainian newborn screened positive for an extremely rare severe combined immunodeficiency (SCID) —purine nucleoside phosphorylase (PNP) deficiency. Ukraine successfully carried out NBS on neonatal dried blood spot (DBS) by real-time PCR, which showed remarkably reduced T-cell receptor and kappa-deleting recombination excision circles (TREC/KREC). Retesting was delayed due to difficult communication with the family. Whole exome sequencing on a new DBS confirmed the diagnosis. The newborn was candidate for al-logeneic hematopoietic stem cell transplantation (HSCT), the only curative treatment. HSCT is a complex procedure still ongoing in Ukraine despite the conflict. However, due to the psychosocial strain, the family sought medical support in Germany, where HSCT was performed successfully at 6 months. As part of a collaborative initiative with Italy, PNP biomarkers were quantified on the same DBSs using tandem mass spectrometry, according to the protocols established for SCID NBS in Tuscany, serving as a proof of concept of its diagnostic performance. This case highlights the importance of sustaining preventive and life-saving healthcare services, and reflects the key role of international partnerships in upholding the right to healthcare in times of crisis.