The early detection of Salla disease through second-tier tests in newborn screening: How to face incidental findings

2014 ◽  
Vol 57 (9) ◽  
pp. 527-531 ◽  
Author(s):  
María L. Couce ◽  
Judit Macías-Vidal ◽  
Daisy E. Castiñeiras ◽  
María D. Bóveda ◽  
José M. Fraga ◽  
...  
2021 ◽  
Vol 4 (2) ◽  
pp. 133-141
Author(s):  
Suma Elcy Varghese ◽  
Rana Hassan Mohammad El Otol ◽  
Fatma Sultan Al Olama ◽  
Salah Ahmad Mohamed Elbadawi

<b><i>Background:</i></b> Early detection of diseases in newborn may help in early intervention and treatment, which may either cure the disease or improve the outcome of the patient. Dubai’s Health Authority has a newborn screening program which includes screening for metabolic and genetic conditions, for hearing and vision, and for congenital heart disease. <b><i>Objectives:</i></b> The objectives of this study are to assess the outcome of the newborn genetic screening program, to correlate the association between the outcome of the program and demographic variables and to find out the percentage of the number of infants who were confirmed to have the genetic disease (by confirmatory tests) out of the total infants who had positive screening test results. <b><i>Methods:</i></b> During the period of the study from January 2018 to December 2018, a total of 7,027 newborns were tested in Dubai Health Authority facilities by the newborn genetic screening program (known as the “Step One Screening”). Blood samples were collected by heel prick on a collection paper. All samples were transported to PerkinElmer Genomics in the USA where the tests were done. The genetic disorders identified were correlated with different variables like gender and nationality. The data were entered in an excel sheet and analyzed by using SPSS software. All infants aged 0–3 months who have done newborn genetic screening at Dubai Health Authority facilities between January and December 2018 were included. <b><i>Results:</i></b> The incidence of screened disorders was 1:7,027 for congenital adrenal hyperplasia, 1:1,757 for congenital hypothyroidism, 1:1,757 for inborn errors of metabolism, 1:2,342 for biotinidase deficiency, 1:1,171 for hemoglobinopathies, 1:12 for hemoglobinopathy traits, and 1:10 for different genetic mutations of G6PD deficiency. <b><i>Conclusions:</i></b> There is a high incidence of different genetic diseases detected by newborn screening. These results justify unifying the program in the UAE and preventive programs like premarital screening and genetic counseling.


2008 ◽  
Vol 107 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Chin-Tung Hsieh ◽  
Wuh-Liang Hwu ◽  
Yuan-Te Huang ◽  
Ai-Chu Huang ◽  
Shiao-Fang Wang ◽  
...  

2016 ◽  
Vol 15 (6) ◽  
pp. 752-758 ◽  
Author(s):  
Sophia Weidler ◽  
Konrad H. Stopsack ◽  
Jutta Hammermann ◽  
Olaf Sommerburg ◽  
Marcus A. Mall ◽  
...  

2008 ◽  
Vol 54 (3) ◽  
pp. 542-549 ◽  
Author(s):  
Devin Oglesbee ◽  
Karen A Sanders ◽  
Jean M Lacey ◽  
Mark J Magera ◽  
Bruno Casetta ◽  
...  

Abstract Background: Newborn screening for maple syrup urine disease (MSUD) relies on finding increased concentrations of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine by tandem mass spectrometry (MS/MS). d-Alloisoleucine (allo-Ile) is the only pathognomonic marker of MSUD, but it cannot be identified by existing screening methods because it is not differentiated from isobaric amino acids. Furthermore, newborns receiving total parenteral nutrition often have increased concentrations of BCAAs. To improve the specificity of newborn screening for MSUD and to reduce the number of diet-related false-positive results, we developed a LC-MS/MS method for quantifying allo-Ile. Methods: Allo-Ile and other BCAAs were extracted from a 3/16-inch dried blood spot punch with methanol/H2O, dried under nitrogen, and reconstituted into mobile phase. Quantitative LC-MS/MS analysis of allo-Ile, its isomers, and isotopically labeled internal standards was achieved within 15 min. To determine a reference interval for BCAAs including allo-Ile, we analyzed 541 dried blood spots. We also measured allo-Ile in blinded samples from 16 MSUD patients and 21 controls and compared results to an HPLC method. Results: Intra- and interassay imprecision (mean CVs) for allo-Ile, leucine, isoleucine, and valine ranged from 1.8% to 7.4%, and recovery ranged from 91% to 129%. All 16 MSUD patients were correctly identified. Conclusions: The LC-MS/MS method can reliably measure allo-Ile in dried blood spots for the diagnosis of MSUD. Applied to newborn screening as a second-tier test, it will reduce false-positive results, which produce family anxiety and increase follow-up costs. The assay also appears suitable for use in monitoring treatment of MSUD patients.


2020 ◽  
Vol 6 (3) ◽  
pp. 51 ◽  
Author(s):  
Trine Tangeraas ◽  
Ingjerd Sæves ◽  
Claus Klingenberg ◽  
Jens Jørgensen ◽  
Erle Kristensen ◽  
...  

In 2012, the Norwegian newborn screening program (NBS) was expanded (eNBS) from screening for two diseases to that for 23 diseases (20 inborn errors of metabolism, IEMs) and again in 2018, to include a total of 25 conditions (21 IEMs). Between 1 March 2012 and 29 February 2020, 461,369 newborns were screened for 20 IEMs in addition to phenylketonuria (PKU). Excluding PKU, there were 75 true-positive (TP) (1:6151) and 107 (1:4311) false-positive IEM cases. Twenty-one percent of the TP cases were symptomatic at the time of the NBS results, but in two-thirds, the screening result directed the exact diagnosis. Eighty-two percent of the TP cases had good health outcomes, evaluated in 2020. The yearly positive predictive value was increased from 26% to 54% by the use of the Region 4 Stork post-analytical interpretive tool (R4S)/Collaborative Laboratory Integrated Reports 2.0 (CLIR), second-tier biochemical testing and genetic confirmation using DNA extracted from the original dried blood spots. The incidence of IEMs increased by 46% after eNBS was introduced, predominantly due to the finding of attenuated phenotypes. The next step is defining which newborns would truly benefit from screening at the milder end of the disease spectrum. This will require coordinated international collaboration, including proper case definitions and outcome studies.


2020 ◽  
Vol 6 (1) ◽  
pp. 10 ◽  
Author(s):  
Dawn S. Peck ◽  
Jean M. Lacey ◽  
Amy L. White ◽  
Gisele Pino ◽  
April L. Studinski ◽  
...  

Enzyme-based newborn screening for Mucopolysaccharidosis type I (MPS I) has a high false-positive rate due to the prevalence of pseudodeficiency alleles, often resulting in unnecessary and costly follow up. The glycosaminoglycans (GAGs), dermatan sulfate (DS) and heparan sulfate (HS) are both substrates for α-l-iduronidase (IDUA). These GAGs are elevated in patients with MPS I and have been shown to be promising biomarkers for both primary and second-tier testing. Since February 2016, we have measured DS and HS in 1213 specimens submitted on infants at risk for MPS I based on newborn screening. Molecular correlation was available for 157 of the tested cases. Samples from infants with MPS I confirmed by IDUA molecular analysis all had significantly elevated levels of DS and HS compared to those with confirmed pseudodeficiency and/or heterozygosity. Analysis of our testing population and correlation with molecular results identified few discrepant outcomes and uncovered no evidence of false-negative cases. We have demonstrated that blood spot GAGs analysis accurately discriminates between patients with confirmed MPS I and false-positive cases due to pseudodeficiency or heterozygosity and increases the specificity of newborn screening for MPS I.


2019 ◽  
Vol 10 ◽  
Author(s):  
Maartje Blom ◽  
Michiel H. D. Schoenaker ◽  
Myrthe Hulst ◽  
Martine C. de Vries ◽  
Corry M. R. Weemaes ◽  
...  

2020 ◽  
Vol 6 (2) ◽  
pp. 33 ◽  
Author(s):  
Dimitar K. Gavrilov ◽  
Amy L. Piazza ◽  
Gisele Pino ◽  
Coleman Turgeon ◽  
Dietrich Matern ◽  
...  

The expansion of the recommend uniform screening panel to include more than 50 primary and secondary target conditions has resulted in a substantial increase of false positive results. As an alternative to subjective manipulation of cutoff values and overutilization of molecular testing, here we describe the performance outcome of an algorithm for disorders of methionine, cobalamin, and propionate metabolism that includes: (1) first tier screening inclusive of the broadest available spectrum of markers measured by tandem mass spectrometry; (2) integration of all results into a score of likelihood of disease for each target condition calculated by post-analytical interpretive tools created byCollaborative Laboratory Integrated Reports (CLIR), a multivariate pattern recognition software; and (3) further evaluation of abnormal scores by a second tier test measuring homocysteine, methylmalonic acid, and methylcitric acid. This approach can consistently reduce false positive rates to a <0.01% level, which is the threshold of precision newborn screening. We postulate that broader adoption of this algorithm could lead to substantial savings in health care expenditures. More importantly, it could prevent the stress and anxiety experienced by many families when faced with an abnormal newborn screening result that is later resolved as a false positive outcome.


2020 ◽  
Vol 6 (1) ◽  
pp. 23 ◽  
Author(s):  
Anne Bergougnoux ◽  
Maureen Lopez ◽  
Emmanuelle Girodon

There has been considerable progress in the implementation of newborn screening (NBS) programs for cystic fibrosis (CF), with DNA analysis being part of an increasing number of strategies. Thanks to advances in genomic sequencing technologies, CFTR-extended genetic analysis (EGA) by sequencing its coding regions has become affordable and has already been included as part of a limited number of core NBS programs, to the benefit of admixed populations. Based on results analysis of existing programs, the values and challenges of EGA are reviewed in the perspective of its implementation on a larger scale. Sensitivity would be increased at best by using EGA as a second tier, but this could be at the expense of positive predictive value, which improves, however, if EGA is applied after testing a variant panel. The increased detection of babies with an inconclusive diagnosis has proved to be a major drawback in programs using EGA. The lack of knowledge on pathogenicity and penetrance associated with numerous variants hinders the introduction of EGA as a second tier, but EGA with filtering for all known CF variants with full penetrance could be a solution. The issue of incomplete knowledge is a real challenge in terms of the implemention of NBS extended to many genetic diseases.


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