Neonatal Blood Spot Screening Research Articles

Haemoglobinopathies and other rare anemias in Spain: ten years of a nationwide registry (REHem-AR).

REHem-AR was created in 2013. The progressive implementation of neonatal screening for haemoglobinopathies in Spanish autonomous communities where the registry had not been implemented, as well as the addition of new centres during this period, has considerably increased the sample of patients covered. In this study, we update our previous publication in this area, after a follow-up of more than 5years. An observational, descriptive, multicentre and ambispective study of adult and paediatric patients with haemoglobinopathies and rare anaemias registered in REHem was performed. The data are from a cross-sectional analysis performed on 1 June, 2023. The study population comprised 1,756 patients, of whom 1,317 had SCD, 214 had thalassaemia and 224 were diagnosed with another condition. Slightly more than one third of SCD patients (37%) were diagnosed based on neonatal bloodspot screening, and the mean age at diagnosis was 2.5years; 71% of thalassaemia patients were diagnosed based on the presence of anaemia. Vaso-occlusive crisis and acute chest syndrome continue to be the most frequent complications in SCD. HSCT was performed in 83 patients with SCD and in 50 patients with thalassaemia. Since the previous publication, REHem-AR has grown in size by more than 500 cases. SCD and TM are less frequent in Spain than in other European countries, although the data show that rare anaemias are frequent within rare diseases. REHem-AR constitutes an important structure for following the natural history of rare anaemias and enables us to calculate investment needs for current and future treatments.

Expanding Neonatal Bloodspot Screening: A Multi-Stakeholder Perspective.

Neonatal bloodspot screening (NBS) aims to detect treatable disorders in newborns. The number of conditions included in the screening is expanding through technological and therapeutic developments, which can result in health gain for more newborns. NBS expansion, however, also poses healthcare, ethical and societal challenges. This qualitative study explores a multi-stakeholders' perspective on current and future expansions of NBS. Semi-structured interviews were conducted with 22 Dutch professionals, including healthcare professionals, test developers and policy makers, and 17 parents of children with normal and abnormal NBS results. Addressed themes were (1) benefits and challenges of current expansion, (2) expectations regarding future developments, and (3) NBS acceptance and consent procedures. Overall, participants had a positive attitude toward NBS expansion, as long as it is aimed at detecting treatable disorders and achieving health gain. Concerns were raised regarding an increase in results of uncertain significance, diagnosing asymptomatic mothers, screening of subgroups (“males only”), finding untreatable disorders, along with increasingly complex consent procedures. Regarding the scope of future NBS expansions, two types of stakeholder perspectives emerged. Stakeholders with a “targeted-scope” perspective saw health gain for the neonate as the exclusive NBS aim. They thought pre-test information could be limited, and parents should be protected against too much options or information. Stakeholders with a “broad-scope” perspective thought the NBS aim should be formulated broader, for example, also taking (reproductive) life planning into account. They put more emphasis on individual preferences and parental autonomy. Policy-makers should engage with both perspectives when making further decisions about NBS.

Neonatal thyrotropin levels and auditory neural maturation in full-term newborns.

ObjectiveThis study aimed to look for a possible relationship between thyrotropin (TSH) values from neonatal bloodspot screening testing and newborn lower auditory pathway myelinization evaluated using the brainstem evoked response audiometry (ABR) test.MethodsSixty-two healthy full-term newborns without perinatal problems were enrolled in the study. TSH results were collected from neonatal bloodspot screening data and were below the test cut-off level (15μUI/mL). The TSH test was performed between three and seven days, and the ABR test was performed in the first 28 days of life. The newborns were divided into two groups: Group 1 (n = 35), TSH between 0 and 5μUI/mL, and group 2 (n = 27), TSH between 5 and 15μUI/mL. Data are presented as mean ± SD, median, or percentage, depending on the variable.ResultsWave latency and interpeak interval values for Groups 1 and 2 were as follows: Wave I: 1.8 ± 0.1 and 1.7 ± 0.1; Wave III: 4.4 ± 0.1 and 4.4 ± 0.1; Wave V: 6.9 ± 0.1 and 6.9 ± 0.1; interval I–III: 2.6 ± 0.1 and 2.6 ± 0.1; interval I–V: 5.1 ± 0.1 and 5.1 ± 0.1; interval III–V: 2.4 ± 0.1 and 2.4 ± 0.1. There were no significant differences in ABR parameters between groups 1 and 2 (p > 0.05). Multiple regression analysis showed a slight significant negative correlation between TSH and wave I values (standardized β = −0.267; p = 0.036), without observing any relationship with the other ABR waves recorded.ConclusionsThis study investigated the relationship of TSH and auditory myelinization evaluated by ABR. It did not show a significant change in lower auditory pathway myelinization according to TSH levels in newborns with TSH screening levels lower than 15 μUI/mL.

Expanded Neonatal Bloodspot Screening Programmes: An Evaluation Framework to Discuss New Conditions With Stakeholders.

Neonatal bloodspot screening (NBS) programmes that screen for rare but serious conditions are expanding worldwide. Fast developments for testing and treatment put pressure on implementation processes. In 2015 the Netherlands embarked on an NBS expansion from 17 to 31 conditions. An evaluation framework was developed based on international NBS frameworks to gain insight in test properties, clinical findings, follow-up and implementation. A stakeholder process took place with implications for the planning of the expanded NBS panel. The evaluation framework progressed into a go/no go framework to start national screening, and is currently explored as basis for continuous evaluation of the NBS panel. The framework and stakeholder process may serve as an example for other programmes.

Neonatal and carrier screening for rare diseases: how innovation challenges screening criteria worldwide

Screening for rare diseases first began more than 50 years ago with neonatal bloodspot screening (NBS) for phenylketonuria, and carrier screening for Tay-Sachs disease, sickle cell anaemia and β-thalassaemia. NBS’s primary aim is health gain for children, while carrier screening enables autonomous reproductive choice. While screening can be beneficial, it also has the potential to cause harm and thus decisions are needed on whether a specific screening is worthwhile. These decisions are usually based on screening principles and criteria. Technological developments, both treatment driven and test driven, have led to expansions in neonatal screening and carrier screening. This article demonstrates how the dynamics and expansions in NBS and carrier screening have challenged four well-known screening criteria (treatment, test, target population and programme evaluation), and the decision-making based on them. We show that shifting perspectives on screening criteria for NBS as well as carrier screening lead to converging debates in these separate fields. For example, the child is traditionally considered to be the beneficiary in NBS, but the family and society can also benefit. Vice versa, carrier screening may be driven by disease prevention, rather than reproductive autonomy, raising cross-disciplinary questions regarding potential beneficiaries and which diseases to include. In addition, the stakeholders from these separate fields vary: Globally NBS is often governed as a public health programme while carrier screening is usually available via medical professionals. The article concludes with a call for an exchange of vision and knowledge among all stakeholders of both fields to attune the dynamics of screening.

Parents\u2019 Perspectives and Societal Acceptance of Implementation of Newborn Screening for SCID in the Netherlands

PurposeWhile neonatal bloodspot screening (NBS) for severe combined immunodeficiency (SCID) has been introduced more than a decade ago, implementation in NBS programs remains challenging in many countries. Even if high-quality test methods and follow-up care are available, public uptake and parental acceptance are not guaranteed. The aim of this study was to describe the parental perspective on NBS for SCID in the context of an implementation pilot. Psychosocial aspects have never been studied before for NBS for SCID and are important for societal acceptance, a major criterion when introducing new disorders in NBS programs.MethodsTo evaluate the perspective of parents, interviews were conducted with parents of newborns with abnormal SCID screening results (N = 17). In addition, questionnaires about NBS for SCID were sent to 2000 parents of healthy newborns who either participated or declined participation in the SONNET-study that screened 140,593 newborns for SCID.ResultsSupport for NBS for SCID was expressed by the majority of parents in questionnaires from both a public health perspective and a personal perspective. Parents emphasized the emotional impact of an abnormal screening result in interviews. (Long-term) stress and anxiety can be experienced during and after referral indicating the importance of uniform follow-up protocols and adequate information provision.ConclusionThe perspective of parents has led to several recommendations for NBS programs that are considering screening for SCID or other disorders. A close partnership of NBS programs’ stakeholders, immunologists, geneticists, and pediatricians-immunologists in different countries is required for moving towards universal SCID screening for all infants.

High resolution melting analysis: a rapid screening and typing tool for common β-thalassemia mutation in Chinese population.

β-thalassemia is a common inherited disorder worldwide including southern China, and at least 45 distinct β-thalassemia mutations have been identified in China. High-resolution melting (HRM) assay was recently introduced as a rapid, inexpensive and effective method for genotyping. However, there was no systemic study on the diagnostic capability of HRM to identify β-thalassemia. Here, we used an improved HRM method to screen and type 12 common β-thalassemia mutations in Chinese, and the rapidity and reliability of this method was investigated. The whole PCR and HRM procedure could be completed in 40 min. The heterozygous mutations and 4 kinds of homozygous mutations could be readily differentiated from the melting curve except c.-78A>G heterozygote and c.-79A>G heterozygote. The diagnostic reliability of this HRM assay was evaluated on 756 pre-typed genomic DNA samples and 50 cases of blood spots on filter paper, which were collected from seven high prevalent provinces in southern China. If c.-78A>G heterozygote and c.-79A>G heterozygote were classified into the same group (c.-78&79 A>G heterozygote), the HRM method was in complete concordance with the reference method (reverse dot blot/DNA-sequencing). In a conclusion, the HRM method appears to be an accurate and sensitive method for the rapid screening and identification of β-thalassemia mutations. In the future, we suggest this technology to be used in neonatal blood spot screening program. It could enlarge the coverage of β-thalassemia screening program in China. At the same time, its value should be confirmed in prospectively clinical and epidemiological studies.

Genetic advances in medicine: has the promise been fulfilled in general practice?

Since the completion of the Human Genome Project, remarkable advances have been made in understanding the human genome's contribution to health and disease; the wealth of scientific discovery generated over the past 10 years is unparalleled in the history of biomedicine, and the rate of discovery is accelerating.1 The traditional study of single gene disorders (genetic medicine) has developed into an understanding of how multiple genes interact with environmental factors: genomics. As these advances were initially greeted with high hopes of early clinical benefit, it is timely to reflect on how much of this promise has filtered through to general practice, particularly in light of The Human Genomics Strategy Group's recent report and policy recommendations about the adoption of genomic technology in the NHS.2 The majority of genetic tests in the UK are still for single gene disorders. Of most relevance to general practice are the common autosomal recessive conditions for which carrier and neonatal disease screening are offered. The adoption of new tests and testing strategies in the NHS has followed careful consideration of research evidence, much of which occurred in general practice.3 With advances in technology, particularly tandem mass spectrometry, the range of conditions included within the neonatal blood spot screening test has expanded (see NHS screening website http://www.screening.nhs.uk/bloodspot-england …

Sequence of Genetic Events in ETV6-RUNX1 Positive B Precursor ALL: Insights from Identical Twins with Concordant Leukaemia

Monozygotic twin pairs with concordant ALL have provided unique insights into the molecular pathogenesis and natural history of childhood leukaemia. Data from twin pair studies and neonatal blood spot screening indicate that ETV6-RUNX1 usually arises as an early or initiating pre-natal event. Its consequence appears to be the generation of a clinically silent or covert but persistent pre-leukaemic clone. Conversion to overt, clinical ALL then requires the acquisition of one or more additional genetic lesions that functionally complement ETV6-RUNX1, often including deletions of the non-rearranged ETV6 allele. Recent genome wide single nucleotide polymorphism (SNP) array based studies have revealed considerably more genetic complexity than previously suspected, with ETV6-RUNX1 cases having an average of 6 (range 1–21) genomic losses or gains (Mullighan et al., Nature 2007, 446: 758). It is however unclear from these descriptive screens or audits when these multiple changes arise in relation to the presumed initiating gene fusion and what functional contribution they make. We have used a series of identical twin pairs with ETV6-RUNX1 positive B precursor ALL to test the proposition that, as we reported previously for ETV6 deletion (Maia et al., Blood 2001, 98: 478), all presumed functional or ‘driver’ genomic changes are post-natal in origin and therefore secondary to ETV6-RUNX1 fusion. If this were to be correct then we anticipated that genomic deletions and gains should be different or distinct within each twin pair. We used 250K Sty and 250K Nsp Affymetrix SNP mapping arrays on 5 pairs of identical twins concordant for ETV6-RUNX1 gene fusion positive ALL. We identified copy number variation using the “in-house” Genome Orientated Laboratory File v2.2.9 software package. The SNP array was performed using leukaemic DNA compared to matched remission DNA for 4 out of 5 cases. The fifth case was compared to a pool of remission DNA. The total number of genetic aberrations found was 51 (excluding T cell receptor and immunoglobulin rearrangements): 36 of these lesions were deletions (mean = 7.2) and 15 amplifications. The commonest aberration, found in 8 out of the 10 children, was a deletion on 12p13.2 involving the ETV6 gene. This was discordant in all cases, consistent with our previous reports using microsatellite markers. Other aberrations included deletions of PAX5, CDKN1B, CDKN2A and CD200/BTLA. The status of these, and other, presumed ‘drivers’ of leukaemogenesis were always different when diagnostic DNA of twins, within a pair, were compared i.e. either the genetic change was absent in one but present in the other, or the alteration was present in both but had distinct genomic boundaries. However in 2 of 5 twin pairs concordant, identical lesions were detected. These were idiosyncratic or very rare genomic changes in ALL and were either in gene sparse regions or involved loci with no known or likely contribution to B cell regulation or leukaemogenesis (e.g. CRYGD). We consider the most likely explanation for these shared genetic events in twin cases is that they arise simultaneously with (or immediately prior to) ETV6-RUNX1 fusion, and in the same incipient pre-ALL stem cell, as collateral damage or ‘passenger’ mutations. These data indicate that the common and presumed ‘driver’ genetic changes that accompany ETV6-RUNX1 in ALL are all secondary to gene fusion and most probably post-natal in origin. It remains to be established whether they contribute at all to the sustained pre-leukaemic state and whether they arise independently of each other and sequentially or as a timed suite or bolus perhaps proximate to diagnosis.

Neonatal Bloodspot Screening

Neonatal bloodspot screening involves taking a small blood sample obtained by pricking a baby's heel. The blood is placed on special filter paper (formerly called the Guthrie card) and sent for analysis. The test is offered to all newborn babies in the UK and is usually carried out by the midwife when the baby is 5–8 days old. It is part of the national child health promotion programme. This article introduces the neonatal bloodspot screening test and describes the features of the important diseases that are currently screened for.

Analysis of amino acids as formamidene butyl esters by electrospray ionization tandem mass spectrometry.

Amino acid formamidene butyl esters are optimally prepared by heating amino acids with dimethylformamide dimethylacetal (DMF-DMA) for 2 minutes at 65 degrees C and then with n-butanol/hydrogen chloride for 15 minutes at 65 degrees C. The formamidene butyl esters of simple alpha-amino acids and beta-amino acids afford between 1.1 and 20 times the signal intensity of the corresponding butyl esters during electrospray ionization tandem mass spectral analysis. Complex alpha-amino acids, such as ornithine, arginine and citrulline, and gamma-amino acids are better analyzed as butyl esters. Secondary alpha-amino acids, such as proline and sarcosine, give a mixture of two iminium salts with the DMF-DMA derivatization method. A derivative incorporating two molecules of the amino acid predominates at higher derivatization temperatures. Contrary to a previous report, N-formylamino acids were not detected. The presence of secondary amino acids in amino acid mixtures, derivatized as formamidene butyl esters, affords derivatives that incorporate two different amino acids. The new formamidene butylation method is unlikely to replace the butylation procedure used by neonatal blood spot screening programs for amino acid disorders, since a much poorer response was obtained with formamidene butyl esters of arginine and citrulline, important in the diagnosis of arginase deficiency and citrullinaemia.