An oligogenic case of severe neonatal thrombocytopenia and a purportedly benign variant in GFI1B requiring reinterpretation.

Although thrombocytopenia in neonatal intensive care patients is rarely due to inherited disorders, the number of genetic variants implicated in platelet defects has grown dramatically with increasing genome-wide sequencing. Here we describe a case of severe, oligogenic neonatal thrombocytopenia and reinterpret a reportedly benign mutation that is likely pathogenic. Despite this patient's synonymous mutation (GFI1B 576 C>T, Phe192=) being annotated as benign, GFI1B is a well-known regulator of megakaryopoiesis, this variant alters splicing and megakaryocyte maturation, and our analysis of existing genome-wide associated studies demonstrates that it likely causes gray platelet syndrome. This variant has not been reported in a case of life-threatening thrombocytopenia. We propose that the severity of this patient's phenotype is due to synergistic epistasis between the intrinsic platelet defect caused by this mutation and her concomitant inherited PMM2 congenital glycosylation disorder neither of which have been associated with such a severe phenotype. This case highlights the importance of whole-exome/genome sequencing for critically ill patients, reexamining variant interpretation when clinically indicated, and the need to study diverse genetic variation in hematopoiesis.

What is the context? Low platelets (thrombocytopenia) in the neonatal population is not frequently inherited. As we perform unbiased DNA sequencing in more patients, the number of inherited platelet disorders and implicated variants is growing.The gene GFI1B encodes for a transcription factor that regulates megakaryocytes, the cell type that produces platelets. A synonymous substitution in GFI1B (576 C>T, Phe192=) is annotated as benign; however, experimental studies have shown that it inhibits megakaryocyte production.There is growing appreciation for oligogenic inheritance, where multiple causal variants contribute to clinical phenotypes.What is new? We present a case of life-threatening neonatal macrothrombocytopenia (large, hypogranulated sparse platelets) that has an oligogenic cause. We reinterpret the synonymous substitution GFI1B 576 C>T as pathogenic.This patient's severe phenotype was likely due to the combined effect of GFI1B 576 C>T and her inherited glycosylation disorder (PMM2-CDG). Neither variant alone causes severe thrombocytopenia, but the combined intrinsic platelet defect (GFI1B mutation) and consumption (PMM2-CDG) likely produced her life-threatening phenotype.What is the impact? GFI1B is a critical regulator of megakaryocyte production. The purportedly benign mutation 576 C>T is likely pathogenic causing thrombocytopenia by impairing megakaryocyte maturation.As more patients have unbiased genome sequencing, oligogenic and polygenic inheritance will become increasingly appreciated as causes of platelet disorders.NICU providers should consider whole genome or exome sequencing of neonates with severe thrombocytopenia after reversible causes are ruled out.

Serum Ferritin Threshold for Iron Deficiency Screening in One-Year-Old Children.

The American Academy of Pediatrics recommends universal hemoglobin screening for iron deficiency anemia using hemoglobin <110 g/L at the 1-year-old well child visit. Our retrospective study suggests the need for combined hemoglobin and serum ferritin iron deficiency screening and raising the diagnostic serum ferritin threshold to 24-25 µg/L.

Intralesional glucocorticoid treatment of an isolated intracranial juvenile xanthogranuloma: a case report.

Juvenile xanthogranuloma is a type of non-Langerhans cell histiocytic process that appears primarily in children and is described as a benign lesion. Although they typically present as a cutaneous lesion, it can also present in other areas including within the central nervous system. We report a 6-month-old infant who presented with seizure-like activity who was found to have a single intracranial mass within the right temporal area on magnetic resonance imaging of the head. The mass was biopsied and pathologically identified as a juvenile xanthogranuloma. In order to avoid the morbidity associated with a gross total resection, an intralesional steroid injection was utilized for treatment which our patient tolerated well. Intralesional steroid injection for the treatment of a symptomatic isolated intracranial juvenile xanthogranuloma has not been described but was successful for our patient.

Novel findings and expansion of phenotype in a mosaic RASopathy caused by somatic KRAS variants.

Mosaic KRAS variants and other RASopathy genes cause oculoectodermal, encephalo-cranio-cutaneous lipomatosis, and Schimmelpenning-Feuerstein-Mims syndromes, and a spectrum of vascular malformations, overgrowth and other associated anomalies, the latter of which are only recently being characterized. We describe eight individuals in total (six unreported cases and two previously reported cases) with somatic KRAS variants and variably associated features. Given the findings of somatic overgrowth (in seven individuals) and vascular or lymphatic malformations (in eight individuals), we suggest mosaic RASopathies (mosaic KRAS variants) be considered in the differential diagnosis for individuals presenting with asymmetric overgrowth and lymphatic or vascular anomalies. We expand the association with embryonal tumors, including the third report of embryonal rhabdomyosarcoma, as well as novel findings of Wilms tumor and nephroblastomatosis in two individuals. Rare or novel findings in our series include the presence of epilepsy, polycystic kidneys, and T-cell deficiency in one individual, and multifocal lytic bone lesions in two individuals. Finally, we describe the first use of targeted therapy with a MEK inhibitor for an individual with a mosaic KRAS variant. The purposes of this report are to expand the phenotypic spectrum of mosaic KRAS-related disorders, and to propose possible mechanisms of pathogenesis, and surveillance of its associated findings.

Complex confounder-corrected R2* mapping for liver iron quantification with MRI.

OBJECTIVES: MRI-based R2* mapping may enable reliable and rapid quantification of liver iron concentration (LIC). However, the performance and reproducibility of R2* across acquisition protocols remain unknown. Therefore, the objective of this work was to evaluate the performance and reproducibility of complex confounder-corrected R2* across acquisition protocols, at both 1.5 T and 3.0 T. METHODS: In this prospective study, 40 patients with suspected iron overload and 10 healthy controls were recruited with IRB approval and informed written consent and imaged at both 1.5 T and 3.0 T. For each subject, acquisitions included four different R2* mapping protocols at each field strength, and an FDA-approved R2-based method performed at 1.5 T as a reference for LIC. R2* maps were reconstructed from the complex data acquisitions including correction for noise effects and fat signal. For each subject, field strength, and R2* acquisition, R2* measurements were performed in each of the nine liver Couinaud segments and the spleen. R2* measurements were compared across protocols and field strength (1.5 T and 3.0 T), and R2* was calibrated to LIC for each acquisition and field strength. RESULTS: R2* demonstrated high reproducibility across acquisition protocols (p > 0.05 for 96/108 pairwise comparisons across 2 field strengths and 9 liver segments, ICC > 0.91 for each field strength/segment combination) and high predictive ability (AUC > 0.95 for four clinically relevant LIC thresholds). Calibration of R2* to LIC was LIC = - 0.04 + 2.62 × 10-2 R2* at 1.5 T and LIC = 0.00 + 1.41 × 10-2 R2* at 3.0 T. CONCLUSIONS: Complex confounder-corrected R2* mapping enables LIC quantification with high reproducibility across acquisition protocols, at both 1.5 T and 3.0 T. KEY POINTS: • Confounder-corrected R2* of the liver provides reproducible R2* across acquisition protocols, including different spatial resolutions, echo times, and slice orientations, at both 1.5 T and 3.0 T. • For all acquisition protocols, high correlation with R2-based liver iron concentration (LIC) quantification was observed. • The calibration between confounder-corrected R2* and LIC, at both 1.5 T and 3.0 T, is determined in this study.

Isobaric Labeling Strategy Utilizing 4-Plex N,N-Dimethyl Leucine (DiLeu) Tags Reveals Proteomic Changes Induced by Chemotherapy in Cerebrospinal Fluid of Children with B-Cell Acute Lymphoblastic Leukemia.

The use of mass spectrometry for protein identification and quantification in cerebrospinal fluid (CSF) is at the forefront of research efforts to identify and explore biomarkers for the early diagnosis and prognosis of neurologic disorders. Here we implemented a 4-plex N,N-dimethyl leucine (DiLeu) isobaric labeling strategy in a longitudinal study aiming to investigate protein dynamics in children with B-cell acute lymphoblastic leukemia (B-cell ALL) undergoing chemotherapy. The temporal profile of CSF proteome during chemotherapy treatment at weeks 5, 10-14, and 24-28 highlighted many differentially expressed proteins, such as neural cell adhesion molecule, neuronal growth regulator 1, and secretogranin-3, all of which play important roles in neurodegenerative diseases. A total of 63 proteins were significantly altered across all of the time points investigated. The most over-represented biological processes from gene ontology analysis included platelet degranulation, complement activation, cell adhesion, fibrinolysis, neuron projection, regeneration, and regulation of neuron death. We expect that results from this and future studies will provide a means to monitor neurotoxicity and develop strategies to prevent central nervous system injury in response to chemotherapy in children.

Quantitative Glycomic Analysis by Mass-Defect-Based Dimethyl Pyrimidinyl Ornithine (DiPyrO) Tags and High-Resolution Mass Spectrometry.

We recently developed a novel amine-reactive mass-defect-based chemical tag, dimethyl pyrimidinyl ornithine (DiPyrO), for quantitative proteomic analysis at the MS1 level. In this work, we further extend the application of the DiPyrO tag, which provides amine group reactivity, optical detection capability, and improved electrospray sensitivity, to quantify N-linked glycans enzymatically released from glycoproteins in the glycosylamine form. Duplex DiPyrO tags that differ in mass by 45.3 mDa were used to label the glycosylamine moieties of freshly released N-glycosylamines from glycoprotein standards and human serum proteins. We demonstrate that both MALDI-LTQ-Orbitrap and nano-HILIC LC/MS/MS Fusion Lumos Orbitrap platforms are capable of resolving the singly or multiply charged N-glycans labeled with mass-defect DiPyrO tags. Dynamic range of quantification, based on MS1 peak intensities, was evaluated across 2 orders of magnitude. With optimized N-glycan release conditions, glycosylamine labeling conditions, and MS acquisition parameters, the N-glycan profiles and abundances in human serum proteins of cancer patients before and after chemotherapy were compared. Moreover, this study also opens a door for using well-developed amine-reactive tags for relative quantification of glycans, which could be widely applied.

Magnetic susceptibility as a B0 field strength independent MRI biomarker of liver iron overload.

PURPOSE: MR-based quantification of liver magnetic susceptibility may enable field strength-independent measurement of liver iron concentration (LIC). However, susceptibility quantification is challenging, due to nonlocal effects of susceptibility on the B0 field. The purpose of this work is to demonstrate feasibility of susceptibility-based LIC quantification using a fat-referenced approach. METHODS: Phantoms consisting of vials with increasing iron concentrations immersed between oil/water layers, and 27 subjects (9 controls/18 subjects with liver iron overload) were scanned. Ferriscan (1.5 T) provided R2-based reference LIC. Multiecho three-dimensional-SPGR (1.5 T/3 T) enabled fat-water, B0- and R2*-mapping. Phantom iron concentration (mg Fe L(-1)) was estimated from B0 differences (ΔB0) between vials and neighboring oil. Liver susceptibility and LIC (mg Fe g(-1) dry tissue) was estimated from ΔB0 between the lateral right lobe of the liver and adjacent subcutaneous adipose tissue. RESULTS: Estimated phantom iron concentrations had good correlation with true iron concentrations (1.5 T:slope = 0.86, intercept = 0.72, r(2) = 0.98; 3 T:slope = 0.85, intercept = 1.73, r(2) = 0.98). In liver, ΔB0 correlated strongly with R2* (1.5 T:r(2) = 0.86; 3 T:r(2) = 0.93) and B0-LIC had good agreement with Ferriscan-LIC (slopes/intercepts nearly 1.0/0.0, 1.5 T:r(2) = 0.67, slope = 0.93 ± 0.13, P ≈ 0.50, intercept = 1.93 ± 0.78, P ≈ 0.02; 3 T:r(2) = 0.84, slope = 1.01 ± 0.09, P ≈ 0.90, intercept = 0.23 ± 0.52, P ≈ 0.68). DISCUSSION: Fat-referenced, susceptibility-based LIC estimation is feasible at both field strengths. This approach may enable improved susceptibility mapping in the abdomen.

Extensive sinovenous thrombosis and hemorrhagic infarction during therapy for T-cell acute lymphoblastic leukemia.

Sinovenous thrombosis (SVT) is a well-recognized and serious complication in children treated for acute leukemia. This frequently occurs during or immediately upon completion of induction therapy and is commonly attributed to asparaginase therapy.Headache is the first and most common clinical symptom to occur during the early development of SVT. With advancement of the thrombosis, the clinical symptoms can progress to increased sleepiness, focal neurological deficit, seizures, and altered consciousness. We report the case of a 4-year-old girl who presented after several days of headaches and anorexia, which then progressed to seizures, left-sided weakness, and altered consciousness. She was later found to have a widespread and occlusive SVT with right cerebral hemorrhagic infarction. This case is notable for the extensive nature of the cerebral SVT and the child's complete clinical recovery from the neurological event. The report discusses the relation of the thrombosis and leukemia and also emphasizes the importance of early recognition and prompt management, while incorporating a collaborative multidisciplinary approach to prevent long-term consequences.

Association of Immune Thrombocytopenia and T-Lymphoblastic Lymphoma in a Pediatric Patient.

Immune thrombocytopenia (ITP) is characterized by isolated thrombocytopenia of unclear etiology. We present a unique case of an 8-year-old girl with chronic ITP who was subsequently diagnosed with T-lymphoblastic lymphoma at age 11. The clinical course was complicated by the occurrence of nonepileptiform events with bizarre behavior changes following the administration of nelarabine and intrathecal and high-dose systemic methotrexate. This case highlights an unusual co-occurrence of hematologic malignancy and chronic ITP in an otherwise healthy child. We speculate that underlying genetic or immunologic lesions may predispose a subset of pediatric ITP patients to the development of hematologic malignancies.

Autoimmune Ataxia During Maintenance Therapy for Acute Lymphoblastic Leukemia.

Neurologic dysfunction during acute lymphoblastic leukemia treatment is commonly associated with chemotherapy. Nonchemotherapy contributions should be considered for persistent atypical symptoms. We describe a boy with acute lymphoblastic leukemia who developed recurrent fevers, diarrhea, progressive ataxia, and neuropsychiatric impairment during maintenance chemotherapy. He was found to have cytomegalovirus in his serum and colon, but not in his cerebrospinal fluid. Instead, his cerebrospinal fluid revealed oligoclonal bands not present in the serum, suggesting an autoimmune process. Prompt treatment with ganciclovir and immunotherapy resulted in marked clinical improvement. Early recognition and treatment of an autoimmune encephalitis is paramount for optimal clinical outcome.

Diagnostic Error in Pediatric Cancer.

The purpose of this study was to ( a) determine the frequency of diagnostic errors in pediatric cancer, ( b) categorize errors, and ( c) underscore themes associated with misdiagnosis. This is a retrospective cohort study at a tertiary children's hospital of 265 patients with new oncologic diagnoses. The diagnostic error rate was 28%. Compared with those with no diagnostic error, those in whom there was an error were more likely to have ( a) more visits before diagnosis ( P < .001), ( b) not been seen in an acute care setting ( P = .03), ( c) inappropriate treatment ( P < .001), and ( d) misinterpreted laboratory studies or imaging ( P < .001). Themes in diagnostic errors were lack of appropriate evaluation for persistent symptoms (47%), failure to recognize signs and symptoms suggestive of malignancy (45%), and misinterpretation of tests (8%). Clinicians should consider diagnostic evaluation for multiple visits for the same complaint or a constellation of signs and symptoms suggestive of malignancy.

Improving Rates of Screening for Anemia in Infancy.

In 2010, the American Academy of Pediatrics recommended universal screening for anemia at approximately 1 year of age. This quality improvement study sought to improve anemia screening in an ambulatory setting. In a large university-based setting, a best practice alert (BPA) was placed within the electronic health record. The primary outcome was overall screening rate in ambulatory family medicine (DFM) and pediatrics (PEDS) clinics. From 2545 pre-BPA clinic visits over a 12-month period, the screening rate was 48.2%. Among 2186 post-BPA clinic visits over an 8-month period, the screening rate improved to 72.7%, P < .0001. Follow-up over a second 7-month period demonstrated sustained improvements (70.8%) but was not higher after educational sessions between the periods. Screening rates were higher in PEDS than DFM at each time point; P < .0001. This technology-based intervention increased and maintained higher screening rates for anemia at 1 year, with higher rates in PEDS.

A tale of three cities--where RHIOS meet the NHIN.

Regional health information exchanges in California, Indiana, and Massachusetts have been collaborating on a prototype for a nationwide health information network, first under the auspices of the Markle Foundation's Connecting for Health program and now under contract to the Department of Health and Human Services' Office of the National Coordinator for Health Information Technology. Since mid-2004, this collaboration has evolved from a collection of regional efforts to a standards-driven cooperative and now to one of four prototype national networks fostered by federal efforts. This development reflects a maturing market for interoperability and integration in healthcare information technology, starting with RHIOs, and suggests one response to the industry's need for the type of plug-and-play information exchange available in other industries. The authors share their experiences and their views of how RHIOs and a Nationwide Health Information Network will further develop to make interoperable electronic health records a reality in coming years. The content of this article is solely the responsibility of the authors and does not necessarily represent the official view of the Office of the National Coordinator for Health Information Technology.

Building consumer trust into health information exchange.

For nationwide health information exchange to succeed, consumers must trust that their data are being managed responsibly. Regional and other networks that create the nationwide exchange should make consumer trust a priority that is factored into every decision they make. Connecting for Health's Common Framework offers a starting point.

Exchanging health information: local distribution, national coordination.

The fragmentation of our health care system, our need to accommodate the diversity of existing health information exchanges, the lack of consistent implementation of clinical information standards, and the need to protect patients' privacy and maintain trust are all challenges to overcome in achieving broad-scale interoperable health information exchange. We propose several steps to coordinate information sharing among regional and other networks through universal adherence to a basic framework of policies and standards. The critical policy action is the identification of a "common framework" of standards and policies, maintained by a new Standards and Policy Entity that reflects both public- and private-sector participation.

Collecting and sharing data for population health: a new paradigm.

Health information technology (IT) has great potential to transform health care and inform population health goals in clinical research, quality measurement, and public safety. To fully realize the benefits of health IT for population health, we must focus on new models that maximize efficiency, encourage rapid learning, and protect patients' privacy. In this paper we explore the advantages of a networked model for analyzing population health information, providing several examples. Although broadening the use of networked models is challenging, the societal benefits of a networked model merit continued exploration and the development of workable solutions.

Health information technology: a few years of magical thinking?

One of the biggest obstacles to expanding the use of information technology (IT) in health care may be the current narrow focus on how to stimulate its adoption. The challenge of thinking of IT as a tool to improve quality requires serious attention to transforming the U.S. health care system as a whole, rather than simply computerizing the current setup. Proponents of health IT must resist "magical thinking," such as the notion that technology will transform our broken system, absent integrated work on policy or incentives. The alternative route to transforming the system sets all of its sights on the destination.