dépistage néonatal

Neonatal screening for congenital metabolic and endocrine disorders is one of the most successful secondary preventive measures in childhood. Newborn children were screened for phenylketonuria as early as the late 1960s, and screening fo

Background: Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies are rare autosomal recessive fatty acid β-oxidation disorders. Their clinical presentations are variable, and premature death is common. They are included in newborn blood spot screening programs in many countries around the world. The current process of screening, through the measurement of acylcarnitines (a metabolic by-product) in dried blood spots with tandem mass spectrometry, is subject to uncertainty regarding test accuracy.Methods: We conducted a systematic review of literature published up to 19th June 2018. We included studies that investigated newborn screening for LCHAD or MTP deficiencies by tandem mass spectrometry of acylcarnitines in dried blood spots. The reference standards were urine organic acids, blood acylcarnitine profiles, enzyme analysis in cultured fibroblasts or lymphocytes, mutation analysis, or at least 10-year follow-up. The outcomes of interest were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Assessment of titles, abstracts, and full-text papers and quality appraisal were carried out independently by two reviewers. One reviewer extracted study data. This was checked by a second reviewer.Results: Ten studies provided data on test accuracy. LCHAD or MTP deficiencies were identified in 23 babies. No cases of LCHAD/MTP deficiencies were identified in four studies. PPV range

Background Newborn screening aims to identify individual patients who could benefit from early management, treatment, and/or surveillance practices. As sequencing technologies have progressed and we move into the era of precision medicine, genomic sequencing has been introduced to this area with the hopes of detecting variants related to a vastly expanded number of conditions. Though implementation of genomic sequencing for newborn screening in public health and clinical settings is limited, commercial laboratories have begun to offer genomic screening panels for neonates. Methods We examined genes listed on four commercial laboratory genomic screening panels for neonates and assessed their clinical actionability using an established age-based semi-quantitative metric to categorize them. We identified genes that were included on multiple panels or distinct between panels. Results Three hundred and nine genes appeared on one or more commercial panels: 74 (23.9%) genes were included in all four commercial panels, 45 (14.6%) were on only three panels, 76 (24.6%) were on only two panels, and 114 (36.9%) genes were listed on only one of the four panels. Eighty-two genes (26.5%) listed on one or more panels were assessed by our method to be inappropriate for newborn screening and to require additional parental decision-making. Conversely, 249 genes that we previously identified as being highly actionable were not listed on any of the four commercial laboratory genomic screening panels. Conclusions Commercial neonatal genomic screening panels have heterogeneous content and may contain some conditions with lower actionability than would be expected for public health newborn screening; conversely, some conditions with higher actionability may be omitted from these panels. The lack of transparency about how conditions are selected suggests a need for greater detail about panel content in order for parents to make informed decisions. The nuanced activity of gene list selection for genomic screening should be iteratively refined with evidence-based approaches to provide maximal benefit and minimal harm to newborns.

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Latin America is a region consisting of 20 countries that present a wide diversity in terms of a geographic area as well as demographics, ethnicity, economy, social, and healthcare systems. Thi

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.

Wilson and Jungner’s recommendations for population-based screening have been used to guide decisions regarding candidate disease inclusion in newborn…

Duchenne Muscular Dystrophy (DMD) is a lethal progressive muscle-wasting disease. New treatment strategies relying on DMD gene exon-skipping therapy have recently been approved and about 30% of patients could be amenable to exon 51, 53 or 45 skipping. We evaluated the spectrum of deletions reported in DMD registries, and designed a method to screen newborns and identify DMD deletions amenable to exon 51, 53 and 45 skipping. We developed a multiplex qPCR assay identifying hemi(homo)-zygotic deletions of the flanking exons of these therapeutic targets in DMD exons (i.e. exons 44, 46, 50, 52 and 54). We conducted an evaluation of our new method in 51 male patients with a DMD phenotype, 50 female carriers of a DMD deletion and 19 controls. Studies were performed on dried blood spots with patient’s consent. We analyzed qPCR amplification curves of controls, carriers, and DMD patients to discern the presence or the absence of the target exons. Analysis of the exons flanking the exon-skipping targets permitted the identification of patients that could benefit from exon-skipping. All samples were correctly genotyped, with either presence or absence of amplification of the target exon. This proof-of-concept study demonstrates that this new assay is a highly sensitive method to identify DMD patients carrying deletions that are rescuable by exon-skipping treatment. The method is easily scalable to population-based screening. This targeted screening approach could address the new management paradigm in DMD, and could help to optimize the beneficial therapeutic effect of DMD therapies by permitting pre-symptomatic care.

Parents use the internet to connect with their peers and access information about a multitude of health topics, including newborn screening (NBS). As the NBS system evolves, education about NBS mus

These leaflets explain the rare but serious diseases covered by the NHS newborn blood spot (NBS) screening programme.

Background Spinal muscular atrophy (SMA) is the most common neurodegenerative disease in childhood. Since motor neuron injury is usually not reversible, early diagnosis and treatment are essential to prevent major disability. Our objective was to assess the impact of genetic newborn screening for SMA on outcome. Methods We provided clinical data from 43 SMA patients, identified via polymerase chain reaction of the SMN1 gene from dried blood spots between January 2018 and January 2020 in Germany. Follow-up included neurophysiological examinations and standardized physiotherapeutic testing. Results Detection of SMA with newborn screening was consistent with known incidence in Germany. Birth prevalence was 1:6910; 39.5% had 2 SMN2 copies, 23% had 3 SMN2 copies, 32.5% had 4 copies, and 4.5% had 5 copies of the SMN2 gene. Treatment with SMA-specific medication could be started at the age of 14–39 days in 21 patients. Pre-symptomatically treated patients remained throughout asymptomatic within the observation period. 47% of patients with 2 SMN2 copies showed early, presumably intrauterine onset of disease. These patients reached motor milestones with delay; none of them developed respiratory symptoms. Untreated children with 2 SMN2 copies died. Untreated children with 3 SMN2 copies developed proximal weakness in their first year. In patients with ≥ 4 SMN2 copies, a follow-up strategy of “watchful waiting” was applied despite the fact that one of them was treated from the age of 6 months. Two infant siblings with 4 SMN2 copies were identified with a missed diagnosis of SMA type 3. Conclusion Identification of newborns with infantile SMA and prompt SMA-specific treatment substantially improves neurodevelopmental outcome, and we recommend implementation in the public newborn screening in countries where therapy is available. Electrophysiology is a relevant parameter to support the urgency of therapy. There has to be a short time interval between a positive screening result and referral to a therapy-ready specialized treatment center.

Newborn screening (NBS) is performed to identify neonates at risk for actionable, severe, early-onset disorders, many of which are genetic. The BabySeq Project randomized neonates to receive conventional NBS or NBS plus exome sequencing (ES) capable of detecting sequence variants that may also diagnose monogenic disease or indicate genetic disease risk. We therefore evaluated how ES and conventional NBS results differ in this population. We compared results of NBS (including hearing screens) and ES for 159 infants in the BabySeq Project. Infants were considered “NBS positive” if any abnormal result was found indicating disease risk and “ES positive” if ES identified a monogenic disease risk or a genetic diagnosis. Most infants (132/159, 84%) were NBS and ES negative. Only one infant was positive for the same disorder by both modalities. Nine infants were NBS positive/ES negative, though seven of these were subsequently determined to be false positives. Fifteen infants were ES positive/NBS negative, all of which represented risk of genetic conditions that are not included in NBS programs. No genetic explanation was identified for eight infants referred on the hearing screen. These differences highlight the complementarity of information that may be gleaned from NBS and ES in the newborn period.

Background Newborn screening for primary carnitine deficiency (NBS) is commonly implemented worldwide; however, it has poor sensitivity. This study aimed to evaluate the feasibility of improving screening by including a second-tier genetic assay.

Conclusion Data from this study revealed that 24% (6/25) of PCD cases would have been missed by conventional NBS. This high-throughput iPLEX assay is a powerful tool for PCD genotyping. The addition of this second-tier genetic screening to the current NBS program could identify missed PCD cases, thereby increasing PCD detection. However, further studies are needed to optimise the workflow of the new screening algorithm and to evaluate the cost-effectiveness of this screening approach.

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare inherited autosomal recessive disorder of biogenic amine metabolism. Diagnosis require…

Knowledge about newborn screening (NBS) is an important factor for parents to make an informed decision about participation. In Europe, countries inform parents differently about their NBS program, potentially including different knowledge aspects in their information. The aim of this study was to assess twenty-six European parental information products and to analyze their knowledge aspects through a content analysis. The analyzed aspects were compared to a list of eight knowledge aspects from scientific literature. The list includes aspects important for parents’ decision-making, such as the purpose of screening. The study showed that most of the eight knowledge aspects are included in NBS information products of the majority of countries. However, there were differences between countries, for example in the amount of detail and phrasing of the information. Additional relevant knowledge aspects have also been identified and are recommended to optimize information products, such as the handling of residual bloodspot samples. This study only assessed knowledge aspects in information products meant for printing, but many countries also use other communication methods, and the impact on knowledge of the delivery of the information needs further study. Preferences of parents on alternative communication methods need to be considered and evaluated on their effectiveness.

(2021). Economic evaluation of point of care universal newborn screening for glucose-6-Phosphate dehydrogenase deficiency in United States. The Journal of Maternal-Fetal & Neonatal Medicine. Ahead of Print.

This article describes an update of the Pompe disease GAA variant database (http://www.pompevariantdatabase.nl) providing new variants and findings related to the genetics of Pompe disease. Th

Journal of Allergy and Clinical Immunology