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Newborn screening for one or more lysosomal disorders has been implemented in several US states, Japan and Taiwan by multiplexed enzyme assays using either tandem mass spectrometry or digital microfluidics. Another multiplex assay making use of immunocapture technology has also been proposed. To investigate the potential variability in performance of these analytical approaches, we implemented three high-throughput screening assays for the simultaneous screening for four lysosomal disorders: Fabry disease, Gaucher disease, mucopolysaccharidosis type I, and Pompe disease. These assays were tested in a prospective comparative effectiveness study using nearly 100,000 residual newborn dried blood spot specimens. In addition, 2nd tier enzyme assays and confirmatory molecular genetic testing were employed. Post-analytical interpretive tools were created using the software Collaborative Laboratory Integrated Reports (CLIR) to determine its ability to improve the performance of each assay vs. the traditional result interpretation based on analyte-specific reference ranges and cutoffs. This study showed that all three platforms have high sensitivity, and the application of CLIR tools markedly improves the performance of each platform while reducing the need for 2nd tier testing by 66% to 95%. Moreover, the addition of disease-specific biochemical 2nd tier tests ensures the lowest false positive rates and the highest positive predictive values for any platform.
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Ornithine transcarbamylase deficiency (OTCD, OMIM 311250), the most common urea cycle disorder, results in impaired synthesis of citrulline from carbamoyl phosphate and ornithine. Individuals have been identified with OTCD due to a contiguous gene deletion at Xp11.4-p21.1 and unique clinical features, described as the "extended OTCD phenotype". We present a male with neonatal-lethal OTCD due to a 1.87Mb microdeletion at Xp11.4-p21.1 (37126841-38998991 hg18). Autopsy revealed a novel histological finding of hepatocyte globular and granular inclusions. Such inclusions have not been described in OTCD or other metabolic disorders and are not an associated finding in neonatal liver failure due to other causes. The deleted region includes the gene SYTL5, potentially involved in RAB27A-dependent membrane trafficking in the liver and placenta. We propose that the contiguous gene deletion could contribute to the severity of the clinical presentation here and hypothesize that deletion of SYTL5 could contribute to the liver findings.
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Proteínas Portadoras/genética , Deleción Cromosómica , Hígado/patología , Proteínas de la Membrana/genética , Enfermedad por Deficiencia de Ornitina Carbamoiltransferasa/genética , Enfermedad por Deficiencia de Ornitina Carbamoiltransferasa/patología , Cromosomas Humanos X , Humanos , Recién Nacido , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido SimpleRESUMEN
IMPORTANCE: Newborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births. OBJECTIVES: To present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments. DESIGN: Epidemiological and retrospective observational study. SETTING: Representatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test. MAIN OUTCOMES AND MEASURES: Infants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked. RESULTS: Screening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia. CONCLUSIONS AND RELEVANCE: Newborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined.
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Linfopenia/diagnóstico , Tamizaje Neonatal/métodos , Inmunodeficiencia Combinada Grave/diagnóstico , Inmunodeficiencia Combinada Grave/epidemiología , Femenino , Humanos , Incidencia , Recién Nacido , Masculino , Pronóstico , Receptores de Antígenos de Linfocitos T/genética , Estudios Retrospectivos , Inmunodeficiencia Combinada Grave/terapia , Análisis de Supervivencia , Linfocitos T/inmunología , Estados UnidosRESUMEN
BACKGROUND: The California newborn screening program uses newborns' dried blood spots (DBS) to screen for more than 45 genetic disorders. Deficiency of galactose-1-phosphate uridyl transferase (GALT) is one of the metabolic genetic disorders screened using newborn DBS. During follow-up tests, common mutations of the GALT gene have been identified using whole blood samples. To avoid the stress of drawing an additional blood sample from newborns who are identified as presumptive positive for galactosemia, we developed a method to test common mutations in the GALT gene using blood spots. METHODS: This method involves DNA extraction from DBS, followed by polymerase chain reaction (PCR), and single nucleotide extension (SNE). SNE products were detected by capillary electrophoresis. RESULTS: In a double-blind study, GALT gene common mutations/variants: IVS2-2A>G, p.S135L, p.T138M, p.Q188R, p.L195P, p.Y209C, p.L218L, p.K285N, and p.N314D were detected in seventy-three DBS which had previously been screened and confirmed as positive in the California Newborn Screening Program. Mutations found using blood spots gave 100% concordance with mutations from previously genotyped whole blood samples. CONCLUSIONS: This blood spot method decreases the genomic test turnaround time of GALT screened positive patients and potentially reduces emotional stress on families required to provide an additional blood draw.
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Análisis Mutacional de ADN/métodos , Pruebas con Sangre Seca , Mutación , UDP-Glucosa-Hexosa-1-Fosfato Uridiltransferasa/sangre , UDP-Glucosa-Hexosa-1-Fosfato Uridiltransferasa/genética , Método Doble Ciego , Técnicas de Genotipaje , Humanos , Recién NacidoRESUMEN
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a fatty acid oxidation disorder with widely varying presentations that has presented a significant challenge to newborn screening (NBS). The Western States Regional Genetics Services Collaborative developed a workgroup to study infants with NBS positive for VLCADD. We performed retrospective analysis of newborns with elevated C14:1-acylcarnitine on NBS in California, Oregon, Washington, and Hawai'i including available confirmatory testing and clinical information. Overall, from 2,802,504 children screened, there were 242 cases screen-positive for VLCADD. There were 34 symptomatic true positive cases, 18 asymptomatic true positives, 112 false positives, 55 heterozygotes, 11 lost to follow-up, and 12 other disorders. One in 11,581 newborns had an abnormal NBS for suspected VLCADD. Comparison of analytes and analyte ratios from the NBS demonstrated statistically significant differences between true positive and false positive groups for C14:1, C14, C14:1/C2, and C14:1/C16. The positive predictive value for all true positive cases was 94%, 54%, and 23% when C14:1 was ≥2.0 µM, ≥1.0 µM, and ≥0.7 µM, respectively. Sequential post-analytical analysis could reduce the referral rate in 25.8% of cases. This study is the largest reported follow-up of infants with NBS screen-positive results for suspected VLCADD and demonstrates the necessity of developing comprehensive and consistent long-term follow-up NBS systems. Application of clinical information revealed differences between symptomatic and asymptomatic children with VLCADD. Comparison of NBS analytes and analyte ratios may be valuable in developing more effective diagnostic algorithms.
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Acil-CoA Deshidrogenasa de Cadena Larga/deficiencia , Errores Innatos del Metabolismo Lipídico/diagnóstico , Enfermedades Mitocondriales/diagnóstico , Enfermedades Musculares/diagnóstico , Tamizaje Neonatal/métodos , Carnitina/análogos & derivados , Carnitina/metabolismo , Síndromes Congénitos de Insuficiencia de la Médula Ósea , Análisis Mutacional de ADN , Demografía , Ácidos Grasos/metabolismo , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Fenotipo , Reproducibilidad de los ResultadosRESUMEN
Precursor-to-product ratios in steroid hormone metabolism may accurately reflect enzymatic activity and production of metabolites relative to their disappearance. The purpose of this study was to explore the use of direct precursor-to-product steroid ratios to discriminate between infants with congenital adrenal hyperplasia (CAH) due to 21- α -hydroxylase deficiency and infants with no disorder, thus characterizing the biochemical phenotype in CAH. Deidentified dried blood spot samples from confirmed CAH cases identified by newborn screen (CAH-positive, N = 8) and from cases with no disorder (CAH-negative, N = 10) were obtained from the California State Newborn Screening Program. Samples (â¼6.25 mm circular spots) underwent methanol and water extraction (9:1 ratio). Deuterated steroids served as isotope internal standards. 17-α-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), androstenedione (A4) and cortisol (F) concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the 17-OHP/S, 17-OHP/A4, and S/F ratios were calculated. The mean 17-OHP and A4 concentrations in samples from CAH cases were significantly increased when compared to cases with no disorder (p = 0.003 for both). 17-OHP/S and 17-OHP/A4 ratios were also significantly elevated in CAH cases (p = 0.007 and p < 0.001, respectively). In contrast, S and F concentrations and the S/F ratio were similar between the two groups. In CAH, the elevated 17-OHP/S ratio is a biomarker of diminished 21-α-hydroxylase activity, and the elevated 17-OHP/A4 ratio is a biomarker of adrenal androgen excess via increased 17,20-lyase activity. The similar S/F ratio indicates that the rate of production via 11-ß-hydroxylase and disappearance of F is maintained in CAH.
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The mucopolysaccharidoses (MPS) result from attenuation or loss of enzyme activities required for lysosomal degradation of the glycosaminoglycans, hyaluronan, heparan sulfate, chondroitin/dermatan sulfate, and keratan sulfate. This review provides a summary of glycan biomarkers that have been used to characterize animal models of MPS, for diagnosis of patients, and for monitoring therapy based on hematopoietic stem cell transplantation and enzyme replacement therapy. Recent advances have focused on the non-reducing terminus of the glycosaminoglycans that accumulate as biomarkers, using a combination of enzymatic digestion with bacterial enzymes followed by quantitative liquid chromatography/mass spectrometry. These new methods provide a simple, rapid diagnostic strategy that can be applied to samples of urine, blood, cerebrospinal fluid, cultured cells and dried blood spots from newborn infants. Analysis of the non-reducing end glycans provides a method for monitoring enzyme replacement and substrate reduction therapies and serves as a discovery tool for uncovering novel biomarkers and new forms of mucopolysaccharidoses.
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Glicosaminoglicanos/química , Mucopolisacaridosis/diagnóstico , Animales , Biomarcadores/química , Cromatografía Liquida , Modelos Animales de Enfermedad , Pruebas con Sangre Seca , Pruebas de Enzimas , Terapia de Reemplazo Enzimático , Glicosaminoglicanos/sangre , Glicosaminoglicanos/líquido cefalorraquídeo , Glicosaminoglicanos/orina , Trasplante de Células Madre Hematopoyéticas , Humanos , Inmunoensayo , Recién Nacido , Espectrometría de Masas , Mucopolisacaridosis/sangre , Mucopolisacaridosis/líquido cefalorraquídeo , Mucopolisacaridosis/terapia , Mucopolisacaridosis/orina , Oxidación-ReducciónRESUMEN
BACKGROUND AND METHODS: There are considerable uncertainty and debate regarding all aspects of newborn screen-positive cases of 3-methylcrotonyl-CoA carboxylase deficiency (3-MCCD), including diagnostic criteria, clinical spectrum, morbidity, prognosis, and appropriate management. To address some of these questions, we queried data from the California Newborn Screening Program's Screening Information System (SIS) and available scanned laboratory reports on cases of 3-MCCD reported by 15 state contracted metabolic specialty care centers born between July 2005 and December 2010. We evaluated the completeness and utility of the database as a tool for clinical disease characterization. RESULTS: During the study period, 2,959,108 infants were screened and 71 infants were diagnosed with 3-MCCD for an overall incidence of 1:41,676. The availability of diagnostic biochemical laboratory data varied significantly from subject to subject. Using a new case classification based on biochemical severity, we found that 8 of the cases met our criteria for biochemically severe (category 1), 19 cases met our criteria for biochemically mild (category 2) that we suspect to possibly be hypomorphic variants or heterozygote carriers, and 44 cases could not be classified (category 3) as mild or severe based on the data available in SIS. Documentation of the treatment regimens also varied significantly with 49% receiving dietary modification and 44% receiving carnitine. 15% of cases were documented to have experienced at least one of the following symptoms: lethargy, vomiting, irritability, ketosis, poor feeding, or poor tone. The majority of the subjects were completely developmentally age appropriate at their last assessment. CONCLUSIONS: The results suggest that a significant portion of the 3-MCCD "confirmed" cases have a mild biochemical phenotype. Moreover the majority of cases had insufficient data entered to allow for adequate clinical characterization of the cases. These findings raise the concern that a significant number of individuals receiving treatment for 3-MCCD may not have a clinically significant condition. Additionally, the utility of this data system could be improved if centers provided complete confirmatory test results and more specific documentation of clinical outcomes and health/developmental status. Further studies, including a clinical chart review, are necessary to validate the data and further characterize this cohort.
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Ligasas de Carbono-Carbono/deficiencia , Tamizaje Neonatal , Trastornos Innatos del Ciclo de la Urea/genética , Acetonitrilos , California , Ligasas de Carbono-Carbono/genética , Carnitina , Humanos , Lactante , Recién Nacido , Trastornos Innatos del Ciclo de la Urea/epidemiología , Trastornos Innatos del Ciclo de la Urea/patologíaRESUMEN
BACKGROUND: Assay of T-cell receptor excision circles (TRECs) in dried blood spots obtained at birth permits population-based newborn screening (NBS) for severe combined immunodeficiency (SCID). OBJECTIVE: We sought to report the first 2 years of TREC NBS in California. METHODS: Since August 2010, California has conducted SCID NBS. A high-throughput TREC quantitative PCR assay with DNA isolated from routine dried blood spots was developed. Samples with initial low TREC numbers had repeat DNA isolation with quantitative PCR for TRECs and a genomic control, and immunophenotyping was performed within the screening program for infants with incomplete or abnormal results. Outcomes were tracked. RESULTS: Of 993,724 infants screened, 50 (1/19,900 [0.005%]) had significant T-cell lymphopenia. Fifteen (1/66,250) required hematopoietic cell or thymus transplantation or gene therapy; these infants had typical SCID (n = 11), leaky SCID or Omenn syndrome (n = 3), or complete DiGeorge syndrome (n = 1). Survival to date in this group is 93%. Other T-cell lymphopenic infants had variant SCID or combined immunodeficiency (n = 6), genetic syndromes associated with T-cell impairment (n = 12), secondary T-cell lymphopenia (n = 9), or preterm birth (n = 8). All T-cell lymphopenic infants avoided live vaccines and received appropriate interventions to prevent infections. TREC test specificity was excellent: only 0.08% of infants required a second test, and 0.016% required lymphocyte phenotyping by using flow cytometry. CONCLUSIONS: TREC NBS in California has achieved early diagnosis of SCID and other conditions with T-cell lymphopenia, facilitating management and optimizing outcomes. Furthermore, NBS has revealed the incidence, causes, and follow-up of T-cell lymphopenia in a large diverse population.
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Linfopenia/diagnóstico , Tamizaje Neonatal , Inmunodeficiencia Combinada Grave/diagnóstico , Linfocitos T/inmunología , California , Femenino , Humanos , Recién Nacido , MasculinoRESUMEN
BACKGROUND: Congenital hydrocephalus is a condition characterized by accumulation of cerebrospinal fluid in the ventricles of the brain. Prenatal infections are risk factors for some birth defects. This pilot study investigated whether residual dried blood spots (DBS) could be used to assess infections as risk factors for birth defects by examining the associations between prenatal infection with Toxoplasma gondii (T. gondii) or cytomegalovirus (CMV) with congenital hydrocephalus. METHODS: Case-infants with hydrocephalus (N=410) were identified among live-born infants using birth defects surveillance systems in California, North Carolina, and Texas. Control-infants without birth defects were randomly selected from the same geographic areas and time periods as case-infants (N=448). We tested residual DBS from case- and control-infants for T. gondii immunoglobulin M and CMV DNA. When possible, we calculated crude odds ratios (cORs) and confidence intervals (CIs). RESULTS: Evidence for prenatal T. gondii infection was more common among case-infants (1.2%) than control-infants (0%; p=0.11), and evidence for prenatal CMV infection was higher among case-infants (1.5%) than control-infants (0.7%; cOR: 2.3; 95% CI: 0.48, 13.99). CONCLUSIONS: Prenatal infections with T. gondii and CMV occurred more often among infants with congenital hydrocephalus than control-infants, although differences were not statistically significant. This pilot study highlighted some challenges in using DBS to examine associations between certain infections and birth defects, particularly related to reduced sensitivity and specimen storage conditions. Further study with increased numbers of specimens and higher quality specimens should be considered to understand better the contribution of these infections to the occurrence of congenital hydrocephalus.
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Infecciones por Citomegalovirus/sangre , Citomegalovirus , Pruebas con Sangre Seca/métodos , Hidrocefalia , Toxoplasma , Toxoplasmosis Congénita/sangre , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/congénito , Femenino , Humanos , Hidrocefalia/sangre , Hidrocefalia/etiología , Hidrocefalia/parasitología , Hidrocefalia/virología , Recién Nacido , Masculino , Estudios Retrospectivos , Toxoplasmosis Congénita/complicaciones , Toxoplasmosis Congénita/virologíaRESUMEN
Ahead of Print article withdrawn by publisher. At request of the authors, this article will be published in the journal Cancer Biomarkers (ISSN 1574-0153).
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PURPOSE: Severe combined immunodeficiency (SCID) is characterized by failure of T lymphocyte development and absent or very low T cell receptor excision circles (TRECs), DNA byproducts of T cell maturation. Newborn screening for TRECs to identify SCID is now performed in several states using PCR of DNA from universally collected dried blood spots (DBS). In addition to infants with typical SCID, TREC screening identifies infants with T lymphocytopenia who appear healthy and in whom a SCID diagnosis cannot be confirmed. Deep sequencing was employed to find causes of T lymphocytopenia in such infants. METHODS: Whole exome sequencing and analysis were performed in infants and their parents. Upon finding deleterious mutations in the ataxia telangiectasia mutated (ATM) gene, we confirmed the diagnosis of ataxia telangiectasia (AT) in two infants and then tested archival newborn DBS of additional AT patients for TREC copy number. RESULTS: Exome sequencing and analysis led to 2 unsuspected gene diagnoses of AT. Of 13 older AT patients for whom newborn DBS had been stored, 7 samples tested positive for SCID under the criteria of California's newborn screening program. AT children with low neonatal TRECs had low CD4 T cell counts subsequently detected (R = 0.64). CONCLUSIONS: T lymphocytopenia in newborns can be a feature of AT, as revealed by TREC screening and exome sequencing. Although there is no current cure for the progressive neurological impairment of AT, early detection permits avoidance of infectious complications, while providing information for families regarding reproductive recurrence risks and increased cancer risks in patients and carriers.
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Ataxia Telangiectasia/diagnóstico , Tamizaje Neonatal , Inmunodeficiencia Combinada Grave/diagnóstico , Secuencia de Aminoácidos , Ataxia Telangiectasia/complicaciones , Ataxia Telangiectasia/genética , Proteínas de la Ataxia Telangiectasia Mutada , Secuencia de Bases , Proteínas de Ciclo Celular/genética , Niño , Preescolar , Proteínas de Unión al ADN/genética , Exoma , Femenino , Humanos , Lactante , Recién Nacido , Linfopenia/genética , Masculino , Mutación , Fenotipo , Polimorfismo de Nucleótido Simple , Proteínas Serina-Treonina Quinasas/genética , Inmunodeficiencia Combinada Grave/complicaciones , Inmunodeficiencia Combinada Grave/genética , Proteínas Supresoras de Tumor/genéticaRESUMEN
OBJECTIVES: The California Prenatal Screening Program serves over 350,000 women annually. This study examines utilization rates for the various screening options and patient choices regarding follow-up services. METHODS: The study tracked patients with first trimester positive results for Down syndrome to examine patient decisions regarding follow-up services and/or additional screening and to identify determinants of patient decisions. For first trimester screen positive women who elected further screening, second trimester integrated screening results were analyzed. The Genetic Disease Screening Program Chromosome Registry was used to identify Down syndrome cases. RESULTS: Ethnicity, but not age, was a strong predictor of acceptance of prenatal diagnosis. Approximately 47% of first trimester screen positive women opted for further screening. Among these women, 46% percent received an integrated screen negative result. All but one confirmed Down syndrome case in this cohort were still screen positive. CONCLUSIONS: Data from the California Prenatal Screening Program indicate that all of the major screening modalities continue to be utilized. The wide range of choices made by women with screen positive results demonstrate the importance of including multiple options within the Program. Providing integrated screening to first trimester Down syndrome screen positive women reduced the number of unnecessary invasive procedures.
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Prestación Integrada de Atención de Salud , Implementación de Plan de Salud/métodos , Prioridad del Paciente , Primer Trimestre del Embarazo , Diagnóstico Prenatal , Adulto , California/epidemiología , Trastornos de los Cromosomas/epidemiología , Cromosomas Humanos Par 13 , Síndrome de Down/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Embarazo , Trisomía , Síndrome de la Trisomía 13 , Adulto JovenRESUMEN
PURPOSE: The purpose of this study was to describe the birth prevalence of genetic disorders among different racial/ethnic groups through population-based newborn screening data. METHODS: Between 7 July 2005 and 6 July 2010 newborns in California were screened for selected metabolic, endocrine, hemoglobin, and cystic fibrosis disorders using a blood sample collected via heel stick. The race and ethnicity of each newborn was self-reported by the mother at the time of specimen collection. RESULTS: Of 2,282,138 newborns screened, the overall disorder detection rate was 1 in 500 births. The disorder with the highest prevalence among all groups was primary congenital hypothyroidism (1 in 1,706 births). Birth prevalence for specific disorders varied widely among different racial/ethnic groups. CONCLUSION: The California newborn screening data offer a unique opportunity to explore the birth prevalence of many genetic disorders across a wide spectrum of racial/ethnicity classifications. The data demonstrate that racial/ethnic subgroups of the California newborn population have very different patterns of heritable disease expression. Determining the birth prevalence of these disorders in California is a first step to understanding the short- and long-term medical and treatment needs faced by affected communities, especially those groups that are impacted by more severe disorders.
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Etnicidad/genética , Enfermedades Genéticas Congénitas/diagnóstico , Enfermedades Genéticas Congénitas/etnología , Tamizaje Neonatal/métodos , California/epidemiología , Hipotiroidismo Congénito/diagnóstico , Hipotiroidismo Congénito/etnología , Hipotiroidismo Congénito/genética , Fibrosis Quística/diagnóstico , Fibrosis Quística/etnología , Fibrosis Quística/genética , Enfermedades Genéticas Congénitas/genética , Pruebas Genéticas/métodos , Hemoglobinas/análisis , Humanos , Recién Nacido , Enfermedades Metabólicas/diagnóstico , Enfermedades Metabólicas/etnología , Enfermedades Metabólicas/genética , Mutación , Prevalencia , AutoinformeRESUMEN
PURPOSE: To improve quality of newborn screening by tandem mass spectrometry with a novel approach made possible by the collaboration of 154 laboratories in 49 countries. METHODS: A database of 767,464 results from 12,721 cases affected with 60 conditions was used to build multivariate pattern recognition software that generates tools integrating multiple clinically significant results into a single score. This score is determined by the overlap between normal and disease ranges, penetration within the disease range, differences between conditions, and weighted correction factors. RESULTS: Ninety tools target either a single condition or the differential diagnosis between multiple conditions. Scores are expressed as the percentile rank among all cases with the same condition and are compared to interpretation guidelines. Retrospective evaluation of past cases suggests that these tools could have avoided at least half of 279 false-positive outcomes caused by carrier status for fatty-acid oxidation disorders and could have prevented 88% of known false-negative events. CONCLUSION: Application of this computational approach to raw data is independent from single analyte cutoff values. In Minnesota, the tools have been a major contributing factor to the sustained achievement of a false-positive rate below 0.1% and a positive predictive value above 60%.
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Tamizaje Neonatal/métodos , Programas Informáticos , Espectrometría de Masas en Tándem/métodos , Biología Computacional , Interpretación Estadística de Datos , Bases de Datos Factuales , Diagnóstico Diferencial , Reacciones Falso Positivas , Humanos , Recién Nacido , Cooperación Internacional , Metaboloma , Minnesota , Análisis Multivariante , Reconocimiento de Normas Patrones Automatizadas , Valor Predictivo de las Pruebas , Estudios RetrospectivosRESUMEN
We report population findings from newborn screening for biotinidase deficiency in California, representing over 2,000,000 newborns. The incidence of profound deficiency was 1/73,629, higher than in other reported populations. Out of 28 patients with profound biotinidase deficiency, 19 were of Hispanic descent, suggesting an increased frequency among this group. Of the 28 patients, 23 underwent mutation analysis of the BTD gene, with one common mutation, 528G>T, found in 43.3% of Hispanic alleles tested.
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Deficiencia de Biotinidasa/epidemiología , Hispánicos o Latinos/estadística & datos numéricos , Biotinidasa/genética , Deficiencia de Biotinidasa/enzimología , California/epidemiología , Análisis Mutacional de ADN , Femenino , Humanos , Incidencia , Recién Nacido , Masculino , Tamizaje NeonatalRESUMEN
BACKGROUND: Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation with highly variable biochemical, genetic, and clinical characteristics. SCADD has been associated with accumulation of butyryl-CoA byproducts, including butyrylcarnitine (C4), butyrylglycine, ethylmalonic acid (EMA), and methylsuccinic acid (MS) in body fluid and tissues. Differences in genotype frequencies have been shown between patients diagnosed clinically versus those diagnosed by newborn screening. Moreover, while patients diagnosed clinically have a variable clinical presentation including developmental delay, ketotic hypoglycemia, epilepsy and behavioral disorders, studies suggest patients diagnosed by newborn screening are largely asymptomatic. Scant information is published about the biochemical, genetic and clinical outcome of SCADD patients diagnosed by newborn screening. METHODS: We collected California newborn screening, follow-up biochemical levels, and ACADS mutation data from September, 2005 through April, 2010. We retrospectively reviewed available data on SCADD cases diagnosed by newborn screening for clinical outcomes. RESULTS: During the study period, 2,632,058 newborns were screened and 76 confirmed SCADD cases were identified. No correlations between initial C4 value and follow-up biochemical markers (C4, EMA or MS levels) were found in the 76 cases studied. We found significant correlation between urine EMA versus MS, and correlation between follow-up C4 versus urine EMA. Of 22 cases where ACADS gene sequencing was performed: 7 had two or more deleterious mutations; 8 were compound heterozygotes for a deleterious mutation and common variant; 7 were homozygous for the common variant c.625G>A; and 1 was heterozygous for c.625G>A. Significant increases in mean urine EMA and MS levels were noted in patients with two or more deleterious mutations versus mutation heterozygotes or common polymorphism homozygotes. Clinical outcome data was available in 31 patients with follow-up extending from 0.5 to 60 months. None developed epilepsy or behavioral disorders, and three patients had isolated speech delay. Hypoglycemia occurred in two patients, both in the neonatal period. The first patient had concomitant meconium aspiration; the other presented with central apnea, poor feeding, and hypotonia. The latter, a c.625G>A homozygote, has had persistent elevations in both short- and medium-chain acylcarnitines; diagnostic workup in this case is extensive and ongoing. CONCLUSIONS: This study examines the largest series to date of SCADD patients identified by newborn screening. Our results suggest that confirmatory tests may be useful to differentiate patients with common variants from those with deleterious mutations. This study also provides evidence to suggest that, even when associated with deleterious mutations, SCADD diagnosed by newborn screening presents largely as a benign condition.
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Acilcoenzima A , Errores Innatos del Metabolismo Lipídico/diagnóstico , Errores Innatos del Metabolismo Lipídico/genética , Tamizaje Neonatal , Acilcoenzima A/sangre , Acilcoenzima A/genética , Acilcoenzima A/orina , Acil-CoA Deshidrogenasa/deficiencia , Acil-CoA Deshidrogenasa/genética , California , Carnitina/análogos & derivados , Carnitina/sangre , Carnitina/orina , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Masculino , Malonatos/sangre , Malonatos/orina , Eliminación de Secuencia , Succinatos/sangre , Succinatos/orinaRESUMEN
BACKGROUND: Newborn screening for congenital adrenal hyperplasia (CAH) is commonly accomplished by measurement of 17-α-hydroxyprogestrone (17-OHP) using enzyme immunoassay (EIA). EIA contributes a significant number of false positives. Therefore, second-tier steroid profile by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is warranted. METHODS: Dried blood spots (DBS) were extracted with a mixture of methanol and water containing the deuterium labeled internal standards of d(8)-17-OHP, d(7)-androstenedione, and d(4)-cortisol. The final extracts were analyzed for 17-OHP, androstenedione and cortisol by LC-MS/MS in the multiple reaction monitoring (MRM) mode. RESULTS: Mean recoveries of the target analytes, 17-OHP, androstenedione and cortisol, were between 97 and 115% with an average intra- and inter-assay CVs ranging from 3.9-9.9% to 3.6-10.1%, respectively. The high efficiency of this method enabled us to test 11,598 specimens, identified as indeterminate by EIA in ~6 years; resulting in 809 presumptive positives reducing the false positives rate by 93%. CONCLUSIONS: The three steroid profile provided better screening outcomes of CAH than 17-OHP concentration alone. Our sample preparation allowed high throughput using common laboratory chemicals. Using three internal standards significantly improved method precision and accuracy. The reduction in false positives significantly reduces anxiety for newborns and their families.
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Hiperplasia Suprarrenal Congénita/diagnóstico , Automatización , Técnicas para Inmunoenzimas/métodos , Enfermedades del Recién Nacido/diagnóstico , Esteroides/sangre , Espectrometría de Masas en Tándem/métodos , Humanos , Recién Nacido , Límite de DetecciónRESUMEN
The California Prenatal Screening Program is designed to make prenatal screening available to the state's large and diverse population. The Program provides information to women which will allow them to make informed choices regarding prenatal screening and prenatal diagnosis. Since the Program's inception in 1986, women in California have had the option to participate in prenatal screening or to decline prenatal screening. The California Program offers prenatal diagnostic services to women whose screening tests indicate an increased risk for birth defects, including Down syndrome. Women can decline any or all of these follow-up services. Genetic counseling, diagnostic services, and the presentation of diagnostic results are performed by medical professionals (not State staff) who follow established guidelines for nondirective counseling. Program data clearly demonstrate that women in California have a wide range of options and make a wide range of choices regarding prenatal screening and prenatal diagnosis. California's comprehensive Prenatal Screening Program promotes optimal care for all women within all options and choices. The important and necessary communication among organizations and stakeholders involved in prenatal screening and diagnosis, and in related care for pregnant women and for people with Down syndrome, is not served by misrepresentation and inflammatory rhetoric.
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Coerción , Síndrome de Down/diagnóstico , Eugenesia , Asesoramiento Genético , Femenino , Humanos , Masculino , EmbarazoRESUMEN
OBJECTIVE: To evaluate the efficiency of California's quadruple-marker screening program and construct receiver-operating characteristic (ROC) curves. METHODS: This study included the screening records of 552 941 women during July 2007 to February 2009. The screen-positive women received clinical follow-up services at state-approved centers. We used the California Chromosome Defect Registry which includes clinical, laboratory, and demographic data from the prenatal diagnostic centers, cytogenetic laboratories, hospitals, and prenatal care providers. Risk calculations, screen-positive rates (SPRs), detection rates (DRs) for chromosomal abnormalities, and 95% confidence intervals (95% CIs) were determined. ROC curves comparing the quadruple-marker to triple-marker screening were constructed. RESULTS: The DR and SPR for trisomy 21 (N = 827) during the quadruple-marker time period were 75.7% (95% CI 72.8-78.6%) and 3.75% (95% CI 3.70-3.80%) compared with 77.4% (95% CI 75.0-79.7%) and 5.4% during the triple-marker phase. The DRs were 78.2% (95% CI 75.0-81.4%) with ultrasound dating and 66.9% (95% CI 59.7-74.0%) for last-menstrual-period-dated pregnancies. For trisomy 18, triploidy, and trisomy 13, the DRs were 84.3, 95.7, and 43.5%, respectively. CONCLUSIONS: The DR for trisomy 21 in California's statewide quadruple-marker screening is very similar to the Program's previously reported DR using triple-marker screening. However, this was achieved at a lower SPR, demonstrating improved screening performance.