Plasma C24:0- and C26:0-lysophosphatidylcholines are reliable biomarkers for the diagnosis of peroxisomal β-oxidation disorders.

The gold-standard diagnostic test for peroxisomal disorders (PDs) is plasma concentration analysis of very long-chain fatty acids (VLCFAs). However, this method's time-consuming nature and limitations in cases which present normal VLCFA levels necessitates alternative approaches. The analysis of C26:0-lysophosphatydylcholine (C26:0-LPC) in dried blood spot samples by tandem-mass spectrometry (MS/MS) has successfully been implemented in certain newborn screening programs to diagnose X-linked adrenoleukodystrophy (ALD).

Foetal Haemoglobin as a Marker of Bone Marrow Suppression Secondary to Anti-Kell Alloimmunisation.

Anti-Kell alloimmunisation is a potentially severe minor blood group type incompatibility, not only as a cause of haemolytic disease of the foetus and newborn, but also due to the destruction of red blood cells (RBC) and mature form in the bone marrow with the subsequent hyporegenerative anaemia. In severe cases and when the foetus shows signs of anaemia, an intrauterine transfusion (IUT) may be necessary. When repeated, this treatment can suppress erythropoiesis and worsen the anaemia.

Early Diagnosis and Treatment of Purine Nucleoside Phosphorylase (PNP) Deficiency through TREC-Based Newborn Screening.

Purine nucleoside phosphorylase (PNP) deficiency is a rare inherited disorder, resulting in severe combined immunodeficiency. To date, PNP deficiency has been detected in newborn screening only through the use of liquid chromatography tandem mass spectrometry. We report the first case in which PNP deficiency was detected by TREC analysis.

Newborn Screening for SCID. Experience in Spain (Catalonia).

Newborn screening (NBS) for severe combined immunodeficiency (SCID) started in Catalonia in January-2017, being the first Spanish and European region to universally include this testing. In Spain, a pilot study with 5000 samples was carried out in Seville in 2014; also, a research project with about 35,000 newborns will be carried out in 2021-2022 in the NBS laboratory of Eastern Andalusia. At present, the inclusion of SCID is being evaluated in Spain.

[Beginnings, evolution and current situation of the Newborn Screening Programs in Spain.].

Newborn Screening Programs (NSP) in Spain were born in the city of Granada in 1968. Till the 1980s, they were developed around the so-called "National Plan for Preventing Subnormality", covering up to 30% of the Spanish newborns. From 1982, when the health system management was transferred to the different autonomous regions, the NSP began to expand, and the bases to transform them into an organized and multidisciplinary activity, integrated and coordinated from the National Health System were settled.

[50 years of the Neonatal Screening Program in Catalonia.].

The Catalonian Newborn Screening Program (CNSP) began in 1969, in Barcelona. It was promoted by Dr. Juan Sabater Tobella and supported by Barcelona Provincial Council and Juan March Foundation.

[Impact of the inclusion of second-tier tests in the newborn screening program of Catalonia and in other international programs.].

Objective: Newborn screening programmes (NBSP) have experienced a qualitative breakthrough due to the implementation of tandem mass spectrometry. However, the tests used give rise to false positives (FP) generating an excessive request for second samples with the consequent anxiety of the families. In order to avoid this problem several programmes have developed second-tier tests (2TT).

[Analysis of the implementation of a unified transportation system of the neonatal screening samples in Catalonia.].

The Neonatal Screening Program in Catalonia from its inception fifty years ago until today, has enabled the early diagnosis and treatment of more than 2,000 newborns. In the last decade, the Program has undergone various extensions regarding its panel of diseases and has improved its evaluation with the inclusion of quality indicators in all its stages. One of the pending subjects of the screening program has been the improvement of the quality indexes related to the sample's arrival time to the laboratory after their extraction.

Identification of 22q11.2 deletion syndrome via newborn screening for severe combined immunodeficiency. Two years' experience in Catalonia (Spain).

Background: The current scenario of newborn screening is changing as DNA studies are being included in the programs of several countries. Severe combined immunodeficiency (SCID) disorders can be detected using quantitative PCR assays to measure T-cell receptor excision circles (TRECs), a byproduct of correct T-cell development. However, in addition to SCID, other T-cell-deficient phenotypes such as 22q11.