Search

Classification of inherited bone marrow failure syndromes (IBMFSs) according to clinical and genetic diagnoses enables proper adjustment of treatment. Unfortunately, 30% of patients enrolled in the Canadian Inherited Marrow Failure Registry (CIMFR) with features suggesting hereditability could not be classified with a specific syndromic diagnosis. We analyzed the outcome of hematopoietic stem cell transplantation (HSCT) in unclassified IBMFSs (uIBMFSs) and the factors associated with outcome. Twenty-two patients with uIBMFSs and 70 patients with classified IBMFSs underwent HSCT. Five-year overall survival of uIBMFS patients after HSCT was inferior to that of patients with classified IBMFSs (56% vs 76.5%). The outcome of patients with uIBMFS who received cord blood was significantly lower than that of patients who received other stem cell sources (14.8% vs 90.9%). Engraftment failure was higher among patients with uIBMFS who received cord blood than those who received bone marrow. None of the following factors were significantly associated with poor survival: transfusion load, transplant indication, the intensity of conditioning regimen, human leukocyte antigen-identical sibling/alternative donor. We suggest that identifying the genetic diagnosis is essential to modulate the transplant procedure including conditioning agents and stem cell sources for better outcome and the standard cord blood transplantation (CBT) should be avoided in uIBMFS.

Background: Patients with sickle cell disease (SCD) are considered at higher risk of severe COVID-19 infection. However, morbidity and mortality rates are variable among countries. To date, there are no published reports that document outcomes of SCD patients with COVID-19 in Canada. Methods: A web-based registry was implemented in June 2020 capturing outcomes of SCD patients with COVID-19 from March 2020 to April 2022 and comparing them to the general population of Quebec, Canada. Results: After 24 months of the pandemic, 185 SCD patients with confirmed SARS-CoV-2 infection were included in the registry. Overall, the population was young (median age 12 years old) and had few comorbidities. No deaths were reported. Risk of hospitalization and admission to intensive care unit (ICU) because of COVID-19 was higher in patients with SCD than in the general population (relative risks (RR) 5.15 (95% confidence interval (95% CI) 3.84–6.91), p ˂ 0.001 and 4.56 (95% CI 2.09–9.93) p ˂ 0.001). A history of arterial hypertension or acute chest syndrome in the past 12 months was associated with a higher risk of severe disease (RR = 3.06 (95% CI 1.85–5.06) p = 0.008 and 2.27 (95% CI 1.35–3.83) p = 0.01). Hospitalized patients had lower hemoglobin F than non-hospitalized patients (12% vs. 17%, p = 0.02). For those who had access to vaccination at the time of infection, 25 out of 26 patients were adequately vaccinated and had mild disease. Conclusions: The SCD population is at higher risk of severe disease than the general population. However, we report favorable outcomes as no deaths occurred. Registries will continue to be critical to document the impact of novel COVID-19 specific therapy and vaccines for the SCD population.

Progressive cytopenia is a serious complication among paediatric patients with inherited bone marrow failure syndromes (IBMFS). Androgens have been used to improve blood counts in different bone marrow failure conditions. Little is known about efficacy and toxicity with new androgens (i.e., danazol) in different types of IBMFS. We identified 29 patients from the Canadian Inherited Marrow Failure Registry, who received oxymetholone or danazol. Sixteen (55%) had haematological response including patients with unclassified IBMFS (45%). Danazol showed a better toxicity profile and similar efficacy compared to oxymetholone. Androgens are an effective and safe option to ameliorate bone marrow failure in IBMFS.

Cisplatin, a chemotherapy used to treat solid tumors, causes acute kidney injury (AKI), a known risk factor for chronic kidney disease and mortality. AKI diagnosis relies on biomarkers which are only measurable after kidney damage has occurred and functional impairment is apparent; this prevents timely AKI diagnosis and treatment. Metabolomics seeks to identify metabolite patterns involved in cell tissue metabolism related to disease or patient factors. The A Canadian study of Cisplatin mEtabolomics and NephroToxicity (ACCENT) team was established to harness the power of metabolomics to identify novel biomarkers that predict risk and discriminate for presence of cisplatin nephrotoxicity, so that early intervention strategies to mitigate onset and severity of AKI can be implemented.Describe the design and methods of the ACCENT study which aims to identify and validate metabolomic profiles in urine and serum associated with risk for cisplatin-mediated nephrotoxicity in children and adults.Observational prospective cohort study.Six Canadian oncology centers (3 pediatric, 1 adult and 2 both).Three hundred adults and 300 children planned to receive cisplatin therapy.During two cisplatin infusion cycles, serum and urine will be measured for creatinine and electrolytes to ascertain AKI. Many patient and disease variables will be collected prospectively at baseline and throughout therapy. Metabolomic analyses of serum and urine will be done using mass spectrometry. An untargeted metabolomics approach will be used to analyze serum and urine samples before and after cisplatin infusions to identify candidate biomarkers of cisplatin AKI. Candidate metabolites will be validated using an independent cohort.Patients will be recruited before their first cycle of cisplatin. Blood and urine will be collected at specified time points before and after cisplatin during the first infusion and an infusion later during cancer treatment. The primary outcome is AKI, defined using a traditional serum creatinine-based definition and an electrolyte abnormality-based definition. Chart review 3 months after cisplatin therapy end will be conducted to document kidney health and survival.It may not be possible to adjust for all measured and unmeasured confounders when evaluating prediction of AKI using metabolite profiles. Collection of data across multiple sites will be a challenge.ACCENT is the largest study of children and adults treated with cisplatin and aims to reimagine the current model for AKI diagnoses using metabolomics. The identification of biomarkers predicting and detecting AKI in children and adults treated with cisplatin can greatly inform future clinical investigations and practices.Le cisplatine, un agent utilisé en chimiothérapie pour traiter les tumeurs solides, entraîne de l’insuffisance rénale aiguë (IRA); un facteur de risque connu de néphropathie chronique et de mortalité. Le diagnostic de l’IRA repose sur des biomarqueurs qui ne sont mesurables qu’après l’apparition d’une lésion rénale et d’une déficience fonctionnelle; ce qui empêche le diagnostic et le traitement précoce de la maladie. La métabolomique s’efforce d’établir le profil des métabolites impliqués dans le métabolisme des tissus cellulaires en relation avec des facteurs liés à la maladie ou au patient. Une étude canadienne portant sur la métabolomique et la néphrotoxicité du cisplatine (ACCENT) s’est amorcée, elle explore la puissance de la métabolomique dans l’identification de nouveaux biomarqueurs permettant de prédire le risque de néphrotoxicité du cisplatine et d’en distinguer la présence. L’objectif étant de mettre en œuvre des stratégies d’intervention précoce, dès l’apparition de l’IRA, et de limiter la gravité de la maladie.Décrire la conception et la méthodologie de l’étude ACCENT. Cette étude vise à établir et à valider des profils métabolomiques, dans l’urine et le sérum, associés au risque de néphrotoxicité médiée par le cisplatine chez les enfants et les adultes.Étude de cohorte prospective.Six centres canadiens d’oncologie (trois centres pédiatriques, un centre pour adultes et deux centres mixtes).L’étude porte sur 300 adultes et 300 enfants pour qui un traitement par cisplatine est prévu.L’IRA sera confirmée par mesure de la créatinine et des électrolytes dans le sérum et l’urine au cours de deux cycles de perfusion de cisplatine. De nombreuses variables relatives au patient et à la maladie seront recueillies prospectivement avant et pendant le traitement. Les analyses métabolomiques des échantillons de sérum et d’urine seront effectuées par spectrométrie de masse. Une approche métabolomique non ciblée sera utilisée pour analyser les échantillons avant et après les perfusions de cisplatine pour identifier les biomarqueurs candidats d’une IRA découlant du traitement par cisplatine. Les métabolites candidats seront validés dans une cohorte indépendante.Les patients seront recrutés avant le premier cycle de cisplatine. Le sang et l’urine seront recueillis à des moments précis, soit avant et pendant le traitement; plus précisément lors de la première perfusion, puis d’une perfusion subséquente au cours du traitement contre le cancer. Le principal critère d’évaluation est la présence d’IRA, laquelle sera établie selon la définition classique fondée sur la mesure de la créatinine sérique et d’une autre définition fondée sur les anomalies électrolytiques. Un examen des dossiers trois mois après la fin du traitement par cisplatine sera effectué afin de documenter la santé rénale et la survie des patients.Il pourrait être impossible de corriger tous les facteurs confusionnels mesurés et non mesurés lors de l’évaluation de la prédiction de l’IRA à l’aide de profils de métabolites. La collecte de données sur plusieurs sites sera un défi.ACCENT est la plus vaste étude portant sur des enfants et des adultes traités avec le cisplatine; cette étude tente de revoir le modèle actuel en utilisant la métabolomique pour diagnostiquer l’IRA. L’identification de biomarqueurs permettant de prédire et de détecter l’IRA chez les enfants et les adultes traités par cisplatine pourrait grandement éclairer les futures études et pratiques cliniques.ClinicalTrials.gov, insuffisance rénale induite par le cisplatine, NCT04442516.

Inherited bone marrow failure syndromes (IBMFSs) such as Fanconi Anemia (FA) and Shwachman-Diamond syndrome (SDS) feature progressive cytopenia and a risk of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Using deep immunophenotypic analysis of hematopoietic stem cells (HSCs) and early progenitors in bone marrow samples from 13 FA/SDS patients without MDS/AML and 6 healthy controls, we revealed relative survival of progenitors that phenotypically resembled granulocyte-monocyte progenitors (GMP) in the patients. In contrast, HSCs, multipotent progenitors, common myeloid progenitors and megakaryocyte-erythroid progenitors were remarkably reduced in FA/SDS patients compared to controls. Whole exome and targeted sequencing of GMP-like cells in leukemia-free patients revealed a prominently higher mutation load in FA/SDS patient samples than in healthy controls. Patient samples also manifested molecular changes that are characteristic of AML: increased G>A/C>T variants, decreased A>G/T>C variants, increased trinucleotide mutations at Xp(C>T)pT, decreased lower mutation rates at Xp(C>T)pG sites compared to other Xp(C>T)pX sites and enrichment for cancer signature 1. AML cells have previously been reported as commonly harboring this cancer signature. Potential pre-leukemic targets in the GMP-like cells from FA/SDS patients included SYNE1, DST, HUWE1, LRP2, NOTCH2 and TP53. Serial analysis of GMPs from a SDS patient, who progressed to AML revealed a gradual increase in mutational burden, enrichment of G>A/C>T signature and emergence of new clones. Interestingly, the molecular signature of marrow cells from two FA/SDS patients with AML was similar to that of FA/SDS without transformation. The predicted founding clones in SDS-AML harbored mutations in several genes including TP53, while in FA-AML the mutated genes included ARID1B and SFPQ. In conclusion, we described an architectural change in the hematopoietic hierarchy of FA/SDS with remarkable preservation of GMP-like populations harboring unique mutation signatures. GMP-like cells might represent a cellular reservoir for clonal evolution. Disclosures No relevant conflicts of interest to declare.

Inherited bone marrow failure syndromes (IBMFSs) are genetically heterogeneous disorders with cytopenia. Many IBMFSs also feature physical malformations and an increased risk of cancer. Point mutations can be identified in about half of patients. Copy number variation (CNVs) have been reported; however, the frequency and spectrum of CNVs are unknown. Unfortunately, current genome-wide methods have major limitations since they may miss small CNVs or may have low sensitivity due to low read depths. Herein, we aimed to determine whether reanalysis of NGS panel data by normalized coverage value could identify CNVs and characterize them. To address this aim, DNA from IBMFS patients was analyzed by a NGS panel assay of known IBMFS genes. After analysis for point mutations, heterozygous and homozygous CNVs were searched by normalized read coverage ratios and specific thresholds. Of the 258 tested patients, 91 were found to have pathogenic point variants. NGS sample data from 165 patients without pathogenic point mutations were re-analyzed for CNVs; 10 patients were found to have deletions. Diamond Blackfan anemia genes most commonly exhibited heterozygous deletions, and included RPS19, RPL11, and RPL5. A diagnosis of GATA2-related disorder was made in a patient with myelodysplastic syndrome who was found to have a heterozygous GATA2 deletion. Importantly, homozygous FANCA deletion were detected in a patient who could not be previously assigned a specific syndromic diagnosis. Lastly, we identified compound heterozygousity for deletions and pathogenic point variants in RBM8A and PARN genes. All deletions were validated by orthogonal methods. We conclude that careful analysis of normalized coverage values can detect CNVs in NGS panels and should be considered as a standard practice prior to do further investigations.

Introduction Sub-cutaneous panniculitis T-cell lymphomas (SPTCL), a rare non-Hodgkin lymphoma, can be associated with hemophagocytic lymphohistiocytosis (HLH), a life-threatening activation of the immune system which adversely impacts survival. T-cell immunoglobulin mucin 3 (TIM-3) is a modulator of immune responses expressed on subgroups of T- and innate immune cells. In this work we describe the first germline variants associated with SPTCL, which are in the TIM-3 gene. Methods We sequenced 27 SPTCL cases to identify gene variants. We performed TIM-3 functional analysis on immune cells from patients and HEK293 cells engineered to overexpress wild-type or mutant TIM-3. Results We identified homozygous, germline, loss-of-function, missense variants in highly conserved residues of TIM-3, namely p.Y82C and p.I97M in about 60% (16/27) of SPTCL cases. These samples were drawn from cases series across 3 continents. Patients with bi-allelic TIM-3 mutations were younger at diagnosis, and several had life-threatening HLH and severe disease course. TIM-3 mutations show specific geographic distribution. Y82C TIM-3 mutations occur on a founder chromosome in patients with East-Asian and Polynesian ancestry, while I97M TIM-3 is observed in Caucasians. Both variants induce protein misfolding and cytoplasmic retention of TIM-3. Loss of TIM-3 membrane expression in TIM-3 mutants abrogates the PD-1/PDL-1 checkpoint and prevents the termination of a Th1-immune response. In HEK293 cells, mutant TIM-3 was not expressed on the cell surface. Defective TIM-3 expression leads to persistent immune activation with increased production of inflammatory cytokines including TNF-alpha and IL-1beta by innate immune cells. Conclusion Our findings highlight HLH/SPTCL as a new genetic entity where loss of the TIM-3 immune checkpoint is associated with T-cell infiltration of adipose tissue and inflammasome activation. This is the first causative germline defect identified in SPTCL. While our findings indicate that TIM-3-mutant HLH/SPTCL benefit from immunomodulation, therapeutic repression of the TIM-3 checkpoint could have serious adverse consequences. Disclosures Prince: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Osteoporotic fractures are a significant cause of morbidity in acute lymphoblastic leukemia (ALL). Our objective was to determine the incidence and predictors of fractures and recovery from osteoporosis in pediatric ALL over 6 years following glucocorticoid initiation. Vertebral fractures (VF) and vertebral body reshaping were assessed on annual spine radiographs, low-trauma non-VF were recorded at regular intervals and spine bone mineral density (BMD) was captured every 6 months for 4 years and then annually. A total of 186 children with ALL were enrolled (median age 5.3 years; range, 1.3 to 17.0 years). The cumulative fracture incidence was 32.5% for VF and 23.0% for non-VF; 39.0% of children with VF were asymptomatic. No fractures occurred in the sixth year and 71.3% of incident fractures occurred in the first 2 years. Baseline VF, cumulative glucocorticoid dose, and baseline lumbar spine (LS) BMD Z-score predicted both VF and non-VF. Vertebral body reshaping following VF was incomplete or absent in 22.7% of children. Those with residual vertebral deformity following VF were older compared to those without (median age 8.0 years at baseline [interquartile range {IQR}, 5.5 to 9.4] versus 4.8 years [IQR, 3.6 to 6.2], p = 0.04) and had more severe vertebral collapse (median maximum spinal deformity index 3.5 [IQR, 1.0 to 8.0] versus 0.5 [IQR, 0.0 to 1.0], p = 0.01). VF and low LS BMD Z-score at baseline as well as glucocorticoid exposure predicted incident VF and non-VF. Nearly 25% of children had persistent vertebral deformity following VF, more frequent in older children, and in those with more severe collapse. These results suggest the need for trials addressing interventions in the first 2 years of chemotherapy, targeting older children and children with more severe vertebral collapse, because these children are at greatest risk for incident VF and subsequent residual vertebral deformity. © 2018 American Society for Bone and Mineral Research.

Introduction Approximately 1500 people live with sickle cell disease (SCD) in the province of Quebec, Canada. Public health has recognized these patients as immunocompromised. SCD patients may be at higher risk of developing severe COVID-19 infection due to their underlying pro-inflammatory and thrombogenic state, splenic dysfunction and secondary organopathies. Descriptions about disease severity and mortality rates in SCD vary widely. From the SECURE-SCD registry, Mucalo et al. recently reported a 0.3% and 4.7% mortality rate in children and adults, respectively. In the French registry, Arlet and colleagues reported a 2.4% death rate among those hospitalized with COVID-19 and SCD, not different from the general population. As a result, the COVID-19 morbidity and mortality rates among the SCD population remain uncertain. Objectives The primary objectives of our study are to describe the epidemiology, baseline characteristics and clinical outcomes of SCD patients with COVID-19 infection in the province of Quebec. In addition, we aim to identify risk factors for hospitalization and severe forms of COVID-19. Methods We built a web-based SCD-COVID-19 registry regrouping 7 adult and 4 paediatric tertiary care hospitals in the province of Quebec in June 2020. All SCD patients with a confirmed SARS-CoV-2 infection by PCR test were included in the study. We compared the prevalence of infection and hospitalization rates of SCD patients to the general population of Quebec using the epidemiological data from the INSPQ (National Institute of Public Health of Quebec) public database. We retrospectively analyzed data included between March 11, 2020 to March 1, 2021. Relative risk was calculated using bilateral association measures (exact fisher, mid-p or chi-squared tests, as appropriate) to compare the incidence of infection and hospitalization of SCD patients to the population of Quebec and to assess risk factors of hospitalization among SCD patients. Results During the first 12 months of the pandemic, 74 patients were included in the registry. The male to female ratio was 1:1.12. Median age was 23 years, ranging from 8 months to 68 years old. SS-Sbeta 0 genotypes were present in 51% of cases, while 49% were SC or Sbeta +. The majority of patients were on disease modifying therapy: 54% were on hydroxyurea and 17.5% on exchange transfusion therapy. The incidence of reported COVID-19 infection was significantly higher in SCD patients compared to the general population (4.9% vs. 3.5% p=0,002) (Table 1). Even more strikingly, SCD had rate of hospitalization 10-times greater than the general population (33.8 vs 3.2%, p A history of acute chest syndrome (ACS) in the last year (OR 2.6 [1.5-4.6], p=0.04) and arterial hypertension (OR 3.3 [2.3-4.8], p=0.01) were associated with a higher risk of hospitalization (Table 2). On the other hand, there was no statistically significant association with age, sex, genotype, ABO blood group, baseline SCD therapy, or other comorbidities (chronic renal disease, obesity, pulmonary hypertension, chronic lung disease and previous admission to ICU) in our cohort. Conclusions Similar to other reports, we found that SCD patients were at much greater risk of hospitalization compared to the general population. We however found no increased risk of mortality or disease complication. This contrasts with results from other registries. A history of ACS and hypertension were associated with a higher risk of hospitalization. Whether social determinants of health could explain some of the outcome variability between different countries merit further investigation. Furthermore, we believe that registries are critical to monitor the impact of preventive measures. As vaccination is ongoing, it will be important to consider its impact on hospitalization and death rate among SCD population. Recruitment to the registry is ongoing and updated data will be presented at the meeting. Figure 1 Figure 1. Disclosures Soulieres: BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding. Forté: Novartis: Honoraria; Canadian Hematology Society: Research Funding; Pfizer: Research Funding.

Introduction: Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome caused by mutations in one of 13 telomere-related genes, resulting in disruption of normal telomere maintenance; however, about 30% of patients do not have a molecular diagnosis. DC patients are at increased risk for severe bone marrow failure (SBMF), myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and solid tumours. Life expectancy is compromised by SBMF, malignancy, pulmonary and liver fibrosis, and GI bleeding. Objectives: Among patients with DC in Canada, aims were to: (1) characterize the genetic profile of DC in Canada, (2) define the spectrum of clinical features of DC, (3) determine the incidence and age when SBMF, MDS, AML or solid tumours develop, (4) identify factors that are associated with higher mortality risk, and (5) describe the causes of death. Methods: Data of patients enrolled in the Canadian Inherited Marrow Failure Registry (CIMFR) and meeting diagnostic criteria for DC between January 1, 2001 and March 1, 2018 were included. The CIMFR is a multicentre registry that captures data on patients with inherited marrow failure syndromes from pediatric tertiary referral centres across all Canadian provinces. We investigated several continuous (e.g. age at diagnosis of SBMF/MDS/AML) and categorical (e.g. mutated gene) variables that are associated with specific outcomes, namely overall survival and development of SBMF. Cox proportional hazard models were used to assess risk of death based on age at diagnosis and presence of SBMF. Kaplan-Meier curves were used to assess overall survival. Results: As of March 1st, 2018, 35 patients with DC were enrolled. The mean age of diagnosis was 10.94 years (0-39.9). The underlying genotypes were: DKC1 (7), TERT (6), TINF2 (5), RTEL1 (3), PARN (2), TERC (2) but remained undetermined in the others (10). Twenty-seven patients were classified as classical DC, 7 had Hoyeraal-Hreidarsson syndrome and 1 patient had Coats plus syndrome. Eight patients (23%) developed SBMF. The mean age of SBMF was 4.22 years (1-8.66). No statistical difference was found between genotypes and progression to SBMF (P=0.1). Modelling death as a function of time varying SBMF status using a cox proportional hazard regression model showed that the presence of SBMF in DC patients was predictive of higher mortality rate (P= 0.009, hazard ratio 5.7, CI 1.54-21.5). None of the patients developed malignancy during childhood (0-18 years). One adult patient developed skin cancer. Eleven patients (31%) received a hematopoietic stem cell transplant (HSCT). The mean age of HSCT was 9.5 years (0.5-37). Ten (29%) patients died, five of whom were recipients of HSCT. Mean age of death was 12.98 years (2-24.6). Extra-hematological complications included gastrointestinal bleeding (50%), pulmonary fibrosis (40%), overwhelming infection (40%), liver fibrosis (20%), cardiomyopathy (10%), hemolytic uremic syndrome (HUS) (10%) and thrombotic microangiopathy (TMA) (10%). Most patients had more than one organ dysfunction. Analysis of survival showed that all patients with TINF2 mutations have died (at median age of 10.8 years, range 2.5-23.25) whereas none died in the TERT group. Patients diagnosed at younger age had lower overall survival compared to patients diagnosed at older ages (P= 0.03, HR: 0.72, CI: 0.57-0.90). All deaths were due to organ dysfunction related to DC. Fifty percent of the patients had concurrent SBMF at the time of death. Conclusion: In this analysis, we characterised the genetic and phenotypic spectrum of DC patients registered in the CIMFR. We found a high mortality rate mainly related to organ dysfunction and SBMF, and described the impact of genotype, earlier age at diagnosis and presence of SBMF in predicting survival. We found that malignancy is an uncommon complication in the pediatric age group. Figure Disclosures Klaassen: Amgen Inc: Consultancy; TranQoL and KIT: Other: creater and owner of Kids ITP tool and TranQoL; Octapharma AG: Speakers Bureau; Baxalta: Speakers Bureau; Biogen Canada Limited: Speakers Bureau; Novo Nordisk Canada Inc: Consultancy; Hoffman-LaRoche Ltd: Consultancy; Agios Pharmaceuticals Inc: Consultancy; Shire Pharma Canada Inc: Consultancy. Pastore:Pfizer: Honoraria. Lipton:BMS: Consultancy, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding.

Subcutaneous panniculitis-like T cell lymphoma (SPTCL), a non-Hodgkin lymphoma, can be associated with hemophagocytic lymphohistiocytosis (HLH), a life-threatening immune activation that adversely affects survival1,2. T cell immunoglobulin mucin 3 (TIM-3) is a modulator of immune responses expressed on subgroups of T and innate immune cells. We identify in ~60% of SPTCL cases germline, loss-of-function, missense variants altering highly conserved residues of TIM-3, c.245A>G (p.Tyr82Cys) and c.291A>G (p.Ile97Met), each with specific geographic distribution. The variant encoding p.Tyr82Cys TIM-3 occurs on a potential founder chromosome in patients with East Asian and Polynesian ancestry, while p.Ile97Met TIM-3 occurs in patients with European ancestry. Both variants induce protein misfolding and abrogate TIM-3’s plasma membrane expression, leading to persistent immune activation and increased production of inflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, promoting HLH and SPTCL. Our findings highlight HLH–SPTCL as a new genetic entity and identify mutations causing TIM-3 alterations as a causative genetic defect in SPTCL. While HLH–SPTCL patients with mutant TIM-3 benefit from immunomodulation, therapeutic repression of the TIM-3 checkpoint may have adverse consequences.

Summary Background Asthma is associated with poorer outcomes in sickle cell disease (SCD). Whether AHR can exist in SCD as a distinct entity, separate and independent of asthma, is unknown. Aims Our goal was to elucidate the prevalence of AHR, as measured by a methacholine challenge test (MCT), in children with SCD who did not have concomitant asthma or any recent history of acute chest syndrome (ACS). To determine if AHR was associated with asthma-like symptoms, we compared the results of the MCT to a validated asthma questionnaire. We also examined if a correlation between AHR and inflammatory markers exists. Methods AHR was identified with a positive MCT defined as a provocation concentration (PC20)

OBJECTIVE: To assess the effect of vertebral fractures (VF) and glucocorticoid (GC) exposure on height deficits in children during treatment of acute lymphoblastic leukemia (ALL). METHODS: Children with ALL treated without cranial radiation therapy (n = 160; median age, 5.1 years; 58.1% male) were followed prospectively for 6 years. Spinal deformity index (SDI) was used to quantify VF status. RESULTS: Baseline height z score ± SD was 0.3 ± 1.2. It fell by 0.5 ± 0.4 in the first 6 months for boys and by 0.4 ± 0.4 in the first 12 months for girls (P < 0.01 for both) and then subsequently recovered. The prevalence of VF peaked at 1 year (17.6%). Among those with VF, median SDI rose from 2 [interquartile range (IQR): 1, 7] at baseline to 8 (IQR: 1, 8) at 1 year. A mixed model for repeated measures showed that height z score declined by 0.13 (95% CI: 0.02 to 0.24; P = 0.02) for each 5-unit increase in SDI during the previous 12 months. Every 10 mg/m(2) increase in average daily GC dose (prednisone equivalent) in the previous 12 months was associated with a height z score decrement of 0.26 (95% CI: 0.20 to 0.32; P < 0.01). CONCLUSIONS: GC likely plays a major role in the observed height decline during therapy for ALL. Because only a minority of children had VF, fractures could not have contributed significantly to the height deficit in the entire cohort but may have been important among the subset with VF.

Osteoporotic fractures are a significant cause of morbidity in acute lymphoblastic leukemia (ALL). Our objective was to determine the incidence and predictors of fractures and recovery from osteoporosis in pediatric ALL over 6 years following glucocorticoid initiation. Vertebral fractures (VF) and vertebral body reshaping were assessed on annual spine radiographs, low-trauma non-VF were recorded at regular intervals and spine bone mineral density (BMD) was captured every 6 months for 4 years and then annually. A total of 186 children with ALL were enrolled (median age 5.3 years; range, 1.3 to 17.0 years). The cumulative fracture incidence was 32.5% for VF and 23.0% for non-VF; 39.0% of children with VF were asymptomatic. No fractures occurred in the sixth year and 71.3% of incident fractures occurred in the first 2 years. Baseline VF, cumulative glucocorticoid dose, and baseline lumbar spine (LS) BMD Z-score predicted both VF and non-VF. Vertebral body reshaping following VF was incomplete or absent in 22.7% of children. Those with residual vertebral deformity following VF were older compared to those without (median age 8.0 years at baseline [interquartile range {IQR}, 5.5 to 9.4] versus 4.8 years [IQR, 3.6 to 6.2], p = 0.04) and had more severe vertebral collapse (median maximum spinal deformity index 3.5 [IQR, 1.0 to 8.0] versus 0.5 [IQR, 0.0 to 1.0], p = 0.01). VF and low LS BMD Z-score at baseline as well as glucocorticoid exposure predicted incident VF and non-VF. Nearly 25% of children had persistent vertebral deformity following VF, more frequent in older children, and in those with more severe collapse. These results suggest the need for trials addressing interventions in the first 2 years of chemotherapy, targeting older children and children with more severe vertebral collapse, because these children are at greatest risk for incident VF and subsequent residual vertebral deformity. © 2018 American Society for Bone and Mineral Research.

Background Phenotypic overlap among the inherited bone marrow failure syndromes (IBMFSs) frequently limits the ability to establish a diagnosis based solely on clinical features. >70 IBMFS genes have been identified, which often renders genetic testing prolonged and costly. Since correct diagnosis, treatment and cancer surveillance often depend on identifying the mutated gene, strategies that enable timely genotyping are essential. Methods To overcome these challenges, we developed a next-generation sequencing assay to analyse a panel of 72 known IBMFS genes. Cases fulfilling the clinical diagnostic criteria of an IBMFS but without identified causal genotypes were included. Results The assay was validated by detecting 52 variants previously found by Sanger sequencing. A total of 158 patients with unknown mutations were studied. Of 75 patients with known IBMFS categories (eg, Fanconi anaemia), 59% had causal mutations. Among 83 patients with unclassified IBMFSs, we found causal mutations and established the diagnosis in 18% of the patients. The assay detected mutant genes that had not previously been reported to be associated with the patient phenotypes. In other cases, the assay led to amendments of diagnoses. In 20% of genotype cases, the results indicated a cancer surveillance programme. Conclusions The novel assay is efficient, accurate and has a major impact on patient care.

Diamond-Blackfan anemia (DBA) features hypoplastic anemia and congenital malformations, largely caused by mutations in various ribosomal proteins. The aim of this study was to characterize the spectrum of genetic lesions causing DBA and identify genotypes that correlate with phenotypes of clinical significance. Seventy-four patients with DBA from across Canada were included. Nucleotide-level mutations or large deletions were identified in 10 ribosomal genes in 45 cases. The RPS19 mutation group was associated with higher requirement for chronic treatment for anemia than other DBA groups. Patients with RPS19 mutations, however, were more likely to maintain long-term corticosteroid response without requirement for further chronic transfusions. Conversely, patients with RPL11 mutations were less likely to need chronic treatment. Birth defects, including cardiac, skeletal, hand, cleft lip or palate and genitourinary malformations, also varied among the various genetic groups. Patients with RPS19 mutations had the fewest number of defects, while patients with RPL5 had the greatest number of birth defects. This is the first study to show differences between DBA genetic groups with regards to treatment. Previously unreported differences in the rate and types of birth defects were also identified. These data allow better patient counseling, a more personalized monitoring plan, and may also suggest differential functions of DBA genes on ribosome and extra-ribosomal functions.

Inherited bone marrow failure syndromes comprise a genetically heterogeneous group of diseases with hematopoietic failure and a wide array of physical malformations. Copy number variants were reported in some inherited bone marrow failure syndromes. It is unclear what impact copy number variants play in patients evaluated for a suspected diagnosis of inherited bone marrow failure syndromes. Clinical and genetic data of 323 patients from the Canadian Inherited Marrow Failure Registry from 2001 to 2014, who had a documented genetic work-up, were analyzed. Cases with pathogenic copy number variants (at least 1 kilobasepairs) were compared to cases with other mutations. Genotype-phenotype correlations were performed to assess the impact of copy number variants. Pathogenic nucleotide-level mutations were found in 157 of 303 tested patients (51.8%). Genome-wide copy number variant analysis by single-nucleotide polymorphism arrays or comparative genomic hybridization arrays revealed pathogenic copy number variants in 11 of 67 patients tested (16.4%). In four of these patients, identification of copy number variant was crucial for establishing the correct diagnosis as their clinical presentation was ambiguous. Eight additional patients were identified to harbor pathogenic copy number variants by other methods. Of the 19 patients with pathogenic copy number variants, four had compound-heterozygosity of a copy number variant with a nucleotide-level mutation. Pathogenic copy number variants were associated with more extensive non-hematological organ system involvement (p = 0.0006), developmental delay (p = 0.006) and short stature (p = 0.04) compared to nucleotide-level mutations. In conclusion, a significant proportion of patients with inherited bone marrow failure syndromes harbor pathogenic copy number variants which were associated with a more extensive non-hematological phenotype in this cohort. Patients with a phenotype suggestive of inherited bone marrow failure syndromes but without identification of pathogenic nucleotide-level mutations should undergo specific testing for copy number variants., Blood disorders: impact of genomic structural variation Copy number variation in patients with inherited bone marrow failure syndromes (IBMFSs) is associated with more severe clinical symptoms. In addition to persistently low levels of red blood cells, white blood cells and/ or platelets, patients with IBMFSs also present varying degrees of physical malformations. Most cases are associated with single base-pair mutations in the DNA sequence, but Canadian researchers led by Yigal Dror at The Hospital for Sick Children in Toronto, have found that whole sections of the genome are deleted or repeated in an important proportion of patients. Those carrying copy number variants (CNV) presented more commonly with developmental delay, short stature and defects in more organ systems, than patients with point mutations. CNV analysis of patients with suspected IBMFSs could aid early disease evaluation and management.

Introduction Inherited bone marrow failure syndromes (IBMFSs) are rare genetic disorders characterized by abnormal hematopoiesis resulting in cytopenias and increased risk of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Once patients develop MDS the only curative therapy is hematopoietic stem cell transplant (HSCT). The rate of progression from early MDS to advanced MDS and AML is variable and risk factors for progression in IBMFS patients are poorly defined. We hypothesized that certain variables could predict the likelihood of progression from early stages of IBMFS-associated MDS/clonal hematopoiesis to advanced MDS or AML, and that the type of disease progression may impact overall survival (OS). Methods Data were collected from patients prospectively enrolled in the Canadian Inherited Marrow Failure Registry (CIMFR), a collaboration of 1 adult and 16 pediatric hospitals in Canada that care for >95% of pediatric IBMFS patients. IBMFS patients were diagnosed as having a specific syndrome or unclassified IBMFS (UCIBMFS) based on published criteria from our lab and others'. Diagnostic criteria for pediatric MDS defined by Hasle et al. were used. Progression of MDS was defined as 1 or more of: (1) a new cytogenetic abnormality, (2) progression in cytopathology from refractory cytopenia (RC) or refractory cytopenia with ringed sideroblasts (RCRS) to refractory cytopenia with dysplasia (RCD), refractory cytopenia with excess blasts (RCEB) or AML, or (3) increased degree of cytopenia severity. Time to progression was described by Kaplan-Meier analysis and risk factors were evaluated using the Cox proportional hazards model. Results Of 601 patients enrolled in CIMFR, 59 (9.8%) developed cytogenetic clones/MDS. Thirteen (22%) had Fanconi Anemia (FA), 13 (22%) had Shwachman-Diamond Syndrome (SDS), 10 (16.9%) had UCIBMFS, and 23 (39%) had other marrow failure syndromes (i.e. Dyskeratosis Congenita, Severe Congenital Neutropenia, Diamond Blackfan Anemia, GATA2-related disorders). The majority presented with cytogenetic clones/RC (n=45, 76%), 9 (15%) had RCEB, 3 (5%) RCD and 1 (1.7%) RCRS. The most common cytogenetic abnormalities at presentation were -7/-7q (n=18, 30%) and isochromosome 7q10 (n=7, 12%). Four patients had complex cytogenetics (6.8%). Of the patients who developed MDS, 32 (54%) went to HSCT. Patients who developed MDS had significantly worse OS (HR 3, 95% CI 2 to 6, p Twenty four MDS patients (40%) had disease progression, with a median time to progression of 4.7 months (1.14-131). Nine patients (38%) with disease progression had FA, 5 (21%) had SDS, 4 (17%) had UC, and 6 (25%) had other marrow failure syndromes. Ten patients (42%) developed more advanced cytopathology, 10 (42%) a new cytogenetic abnormality, and 5 (20%) worsening cytopenias. Eight patients progressed from RC to RCEB, with a median time to progression of 5.7 months (1.14 to 113). Progression to more advanced cytopathology was associated with lower OS (HR 2.7, 95% CI 1.0 to 7.4, p=0.046). Median time to progression of cytogenetics was 4.13 months (1.14 to 131), which was not predictive of worse OS (p=0.22). Notably, there was no difference in OS or risk of progression between the -7/-7q and isochromosome 7q groups (p=0.644). Finally, patients who progressed due to worsening cytopenias had significantly lower OS compared to those who did not (p=0.011), but numbers were small. Seventeen (71%) of the MDS patients who progressed underwent HSCT. Conclusion Development of MDS has a significant adverse impact on the OS of IBMFS patients, with disease progression occurring 4.7 months from MDS diagnosis. Progression to advanced cytopathology is associated with decreased survival, while worsening cytogenetic clones and cytopenias may not carry the same risk. Importantly, isochromosome 7q10 is also associated with a risk of progression to more severe hematological disease, and may have an impact on survival. Further analysis of additional variables (i.e. HSCT) will provide insight into the important predictors of survival and disease progression, and help to guide treatment decisions for this high-risk patient population. Disclosures No relevant conflicts of interest to declare.

Background: Over the last decade major progress has been made in developing new diagnostic methods and in phenotypic and molecular classification of inherited bone marrow failure syndromes (IBMFSs). Nevertheless, data from the Canadian Inherited Marrow Failure Registry (CIMFR) indicates that 28% of patients with inherited bone marrow failure syndromes (IBMFS) cannot be assigned a specific syndromic diagnosis. These unclassified IBMFS (UIBMFS) cases may represent either novel syndromes or atypical presentations of previously described disorders. Hematopoietic stem cell transplantation (HSCT) is the only curative option for bone marrow failure and malignant myeloid transformation in IBMFSs. However, it is unknown whether the application of this treatment to UIBMFS patients without an ability to modify the procedure according to the underlying genetic and syndromic diagnosis affects outcome. To our knowledge, there are no published transplant data on cohorts of patients with UIBMFSs. The aims of this study were to evaluate the outcome and prognostic factors of HSCT in a cohort of patients with UIBMFSs and to determine whether the knowledge of the syndromic/genetic diagnosis before HSCT has an impact on transplant outcome. Methods: Patients were enrolled on the CIMFR if they were diagnosed with a specific IBMFSs (e.g. Fanconi anemia), and/or they had bone marrow failure and either a family history of bone marrow, or physical malformations or a diagnosis before the age of one year. Patients were considered as having an UIBMFS if they fulfilled the above criteria, but could not be assigned a specific syndromic diagnosis since they did not meet the diagnostic criteria for any known IBMFS. HSCT data were extracted from the CIMFR database and analyzed. Descriptive statistics were used to compare between groups. Cox proportional hazards model was used for univariate analysis to identify risk factors for worse overall survival post HSCT in patients with UIBMFSs. Results: Among the patients enrolled in the CIMFR, 22 with UIBMFSs and 68 with classified IBMFSs (CIBMFSs) underwent HSCT between January 2001 and December 31, 2017. Transplanted patients with UIBMFSs were hematologically characterized by multilineage cytopenia (n=13), single-lineage cytopenia (n=1), myelodysplastic syndrome (MDS) (n=5) or acute myeloid leukemia (AML) (n=3). Patients with CIBMFSs had Fanconi anemia (n=30), dyskeratosis congenita (n=7), Shwachman-Diamond syndrome (n=9), Kostmann syndrome (n=6), Diamond-Blackfan anemia (n=4) or others (n= 11). Median age at diagnosis of patients with UIBMFSs was 4.18 years (range; 0 to 32.0 years) and median age at HSCT for UIBMFSs was 5.74 years (range; 0.17-66.67 years). Median time between diagnosis of UIBMFS and HSCT was 0.48 years (range; 0.12 - 34.67), this was significantly shorter than that of CIBMFS (1.77 years, range; 0.17 - 15 years, P=0.014). Six patients (27.3%) of UIBMFS and 9 patients (19.7%) with CIBMFS underwent HSCT for MDS-RCEB or AML (P=0.15). The overall 5-year survival of UIBMFS patients was significantly inferior to that of CIBMFS patients: 56±11.4% vs. 76±5.5%, respectively (P=0.047). 5-year overall survival of patients with UIBMFSs was significantly worse among those whose stem cell source was cord blood (15±13.3%) vs. those who received other stem cell sources (91±8.7%, P=0.04), while stem cell source did not affect prognosis of patients with CIBMFSs. Engraftment failure among UIBMFS patients who received cord blood was significantly higher than engraftment failure among those who received bone marrow (55.6% vs. 9.1%, P=0.024). No other factors reached statistical significance when the impact of stem cell source on overall survival was analyzed, including transfusion load, transplant indications, intensity of conditioning regimens, related/non-related donor, degree of human leukocyte antigen (HLA) matching or identifying a diagnosis after HSCT. Conclusion: Identifying the syndromic diagnosis of IBMFSs is critically important when considering HSCT. The worse HSCT outcome of UIBMFSs in this study might be related to an inability to tailor the transplant approach to the patient specific phenotype and genotype. Our data suggest that cord blood should be avoided as a stem cell source in patients with UIBMFSs. Disclosures No relevant conflicts of interest to declare.

Purpose: The current recommended practice for pediatric patients with metastatic rhabdomyosarcoma includes full-dose radiotherapy to each metastatic site. We wished to question this practice, which can cause side-effects and is often logistically challenging, by studying the pattern of failure in our pediatric and teenage patient population. Methods and Materials: Our institution’s cancer registry was queried for patients diagnosed with rhabdomyosarcoma aged 18 or less from January 1990 until January 2014. Twenty-nine patients were found and, of these, six had metastatic disease. Five of the six were treated with standard chemotherapy together with radiotherapy to the primary and metastatic sites with doses and fractionation according to the site. Progression-free survival was calculated from the end of radiotherapy until radiological or pathological evidence of disease progression or death. Results: Median age was 13 years (range: 12-18). Three were girls. All had alveolar histology and unfavorable primary sites. Twelve metastatic sites were treated with radiotherapy. Doses used were 41.4 - 50.4 Gy in 1.8 Gy fractions for most sites, and 15 Gy in 1.5 Gy fractions for whole lung radiotherapy. The median number of sites treated per patient was two (range: 1 - 6). Median time to progression was 10.1 months (range: 1.9 - 15.7). Local control was 100% for all metastatic sites. Median overall survival (OS) was 31.8 months (range: 20.4 – 95.4 months). Three patients developed progressive disease outside the treated field. One patient died from a secondary hematological malignancy without evidence of disease progression. One patient remains progression-free at 88.6 months post-radiotherapy. Conclusions: Radiotherapy to metastatic disease sites prevented in-field progression in all five patients with metastatic alveolar rhabdomyosarcoma. However, failure at sites outside of the radiotherapy volume occurred in three of five of patients and overall survival was very poor despite aggressive treatment to all sites of disease. Radiotherapy has a role in metastatic disease, although future studies evaluating dose and fractionation are needed.

Purpose Vertebral fractures due to osteoporosis are a potential complication of childhood acute lymphoblastic leukemia (ALL). To date, the incidence of vertebral fractures during ALL treatment has not been reported. Patient and Methods We prospectively evaluated 155 children with ALL during the first 12 months of leukemia therapy. Lateral thoracolumbar spine radiographs were obtained at baseline and 12 months. Vertebral bodies were assessed for incident vertebral fractures using the Genant semiquantitative method, and relevant clinical indices such as spine bone mineral density (BMD), back pain, and the presence of vertebral fractures at baseline were analyzed for association with incident vertebral fractures. Results Of the 155 children, 25 (16%; 95% CI, 11% to 23%) had a total of 61 incident vertebral fractures, of which 32 (52%) were moderate or severe. Thirteen (52%) of the 25 children with incident vertebral fractures also had fractures at baseline. Vertebral fractures at baseline increased the odds of an incident fracture at 12 months by an odds ratio of 7.3 (95% CI, 2.3 to 23.1; P = .001). In addition, for every one standard deviation reduction in spine BMD Z-score at baseline, there was 1.8-fold increased odds of incident vertebral fracture at 12 months (95% CI, 1.2 to 2.7; P = .006). Conclusion Children with ALL have a high incidence of vertebral fractures after 12 months of chemotherapy, and the presence of vertebral fractures and reductions in spine BMD Z-scores at baseline are highly associated clinical features.

In the version of this article originally published, the main-text sentence “In three patients of European ancestry, we identified the germline variant encoding p.Ile97Met in TIM-3, which was homozygous in two (P12 and P13) and heterozygous in one (P15) in the germline but with no TIM-3 plasma membrane expression in the tumor” misstated the identifiers of the two homozygous individuals, which should have been P13 and P14. The error has been corrected in the HTML, PDF and print versions of the paper.

Vertebral compression is a serious complication of childhood acute lymphoblastic leukemia (ALL). The prevalence and pattern of vertebral fractures, as well as their relationship to bone mineral density (BMD) and other clinical indices, have not been systematically studied. We evaluated spine health in 186 newly diagnosed children (median age 5.3 years, 108 boys) with ALL (precursor B cell: N=167; T-cell: N=19), who were enrolled in a national bone health research program. Patients were assessed within 30 days of diagnosis by lateral thoraco-lumbar spine radiograph, bone age (also used for metacarpal morphometry) and BMD. Vertebral morphometry was carried out by the Genant semi-quantitative method. Twenty-nine patients (16%) had a total of 75 grade 1 or higher prevalent vertebral compression fractures (53 thoracic, 71%; 22 lumbar). Grade 1 fractures as the worst grade were present in 14 children (48%), 9 patients (31%) had grade 2 fractures, and 6 children (21%) had grade 3 fractures. The distribution of spine fracture was bi-modal, with most occurring in the mid-thoracic and thoraco-lumbar regions. Children with grade 1 or higher vertebral compression had reduced lumbar spine (LS) areal BMD Z-scores compared to those without (mean±SD, −2.1±1.5 vs. −1.1±1.2; P < 0.001). LS BMD Z-score, second metacarpal percent cortical area Z-score, and back pain were associated with increased odds for fracture. For every 1 SD reduction in LS BMD Z-score, the odds for fracture increased by 80% (95% CI 10% to 193%); the presence of back pain had an odds ratio of 4.7 (95% CI, 1.5 to 14.5). These results show that vertebral compression is an under-recognized complication of newly diagnosed ALL. Whether the fractures will resolve through bone growth during or after leukemia chemotherapy remains to be determined.

PEComa of the gastrointestinal tract, composed of perivascular epithelioid cells with myomelanocytic differentiation, is rare with previous literature limited to 16 case reports. There is a marked female preponderance and approximately one-third of the cases occur in the pediatric age group. We report PEComa with lymph node involvement occurring in the rectum of a 15-year-old girl, treated by surgical resection and adjuvant chemotherapy. The patient is well at 9 months follow-up with neither radiologic nor endoscopic evidence of recurrence. We review the differential diagnosis of intestinal PEComa, which includes malignant melanoma, epithelioid gastrointestinal stromal tumors, clear cell sarcoma of soft parts, alveolar soft part sarcoma, leiomyosarcoma with HMB45 expression, and paraganglioma. Immunohistochemistry can rule out many of these morphologically similar tumors but differentiation from clear cell sarcoma may require reverse transcription-polymerase chain reaction. We discuss the determination of pathologic features indicative of malignancy in PEComa, which is complicated in the gastrointestinal tract due to the small number of cases, variability of pathologic features reported, and inconsistent reporting of outcome. All 4 tumors reporting early recurrence or progression were greater than 5 cm in size and had areas of coagulative tumor necrosis. In addition, high nuclear grade and lymphovascular invasion were seen in 2 of these 4 cases. We propose that a minimum dataset for gastrointestinal PEComa should include these features along with mitotic count, infiltrative border, and tumor stage analogous to that used in colorectal carcinoma.

OBJECTIVE. Unclassified inherited bone marrow failure syndromes are a heterogeneous group of genetic disorders that represent either new syndromes or atypical clinical courses of known inherited bone marrow failure syndromes. The relative prevalence of the unclassified inherited bone marrow failure syndromes and their characteristics and the clinical and economic challenges that they create have never been studied. METHODS. We analyzed cases of inherited bone marrow failure syndrome in the Canadian Inherited Marrow Failure Registry that were deemed unclassifiable at study entry. RESULTS. From October 2001 to March 2006, 39 of the 162 patients enrolled in the Canadian Inherited Marrow Failure Registry were registered as having unclassified inherited bone marrow failure syndromes. These patients presented at a significantly older age (median: 9 months) than the patients with classified inherited bone marrow failure syndrome (median: 1 month) and had substantial variation in the clinical presentations. The hematologic phenotype, however, was similar to the classified inherited bone marrow failure syndromes and included single- or multiple-lineage cytopenia, severe aplastic anemia, myelodysplasia, and malignancy. Grouping patients according to the affected blood cell lineage(s) and to the presence of associated physical malformations was not always sufficient to characterize a condition, because affected members from several families fit into different phenotypic groups. Compared with the classified inherited bone marrow failure syndromes, the patients with unclassified inherited bone marrow failure syndromes had 3.2 more specific diagnostic tests at 4.5 times higher cost per evaluated patient to attempt to categorize their syndrome. At last follow-up, only 20% of the unclassified inherited bone marrow failure syndromes were ultimately diagnosed with a specific syndrome on the basis of the development of new clinical findings or positive genetic tests. CONCLUSIONS. Unclassified inherited bone marrow failure syndromes are relatively common among the inherited bone marrow failure syndromes and present a major diagnostic and therapeutic dilemma.

Background: Iron chelation therapy (ICT) with deferoxamine (DFO), the current standard for the treatment of iron overload in patients with transfusion-dependent disorders such as beta-thalassemia, requires regular subcutaneous or intravenous infusions. This can lead to reduced quality of life and poor adherence, resulting in increased morbidity and mortality in iron-overloaded patients with beta-thalassemia. Deferasirox is an orally administered iron chelator that has been approved for use in the United States, Switzerland, and other countries. Objective: This analysis was conducted to compare patient-reported outcomes (PROs) during receipt of DFO infusions or once-daily oral therapy with deferasirox (ICL670). Methods: PROs were prospectively evaluated as part of a randomized, Phase III study comparing the efficacy and safety profile of DFO 20 to 60 mg/kg per day with those of deferasirox 5 to 30 mg/kg per day in patients (age >= 2 years) with beta-thalassemia who were receiving regular transfusions and had a liver iron concentration of >= 2 mg/g dry weight. PRO questionnaires were completed by patients or a parent or legal guardian at baseline, week 4, week 24, and end of study (EOS). Patients assessed their level of satisfaction with study treatment (very satisfied, satisfied, neutral, dissatisfied, or very dissatisfied) and rated its convenience (very convenient, convenient, neutral, inconvenient, or very inconvenient). Time lost from normal activities due to ICT in the previous 4 weeks was recorded using a single global assessment. At week 4, patients who had previous experience with DFO were asked to indicate their preference for treatment JCT received before the study, ICT received during the study, no preference, or no response) and the reason for that preference. At EOS, all patients were asked if they would be willing to continue using the ICT they had received during the study. All study analyses were performed in all patients who received at least 1 dose of study medication. Results: Five hundred eighty-six patients (304 females, 282 males; age range, 2-53 years) received treatment with DFO (n = 290) or deferasirox (n = 296). Significantly more patients treated with deferasirox reported being very satisfied or satisfied with treatment compared with those treated with DFO (week 4: 92.0% vs 50.4%, respectively; week 24: 89.6% vs 44.0%; EOS: 85.1% vs 38.7%; all, P < 0.001). At the same time points, the majority of those treated with deferasirox reported that treatment was very convenient or convenient compared with those treated with DFO (95.5% vs 21.3%, 91.7% vs 17.4%, and 92.7% vs 11.3%, respectively; all, P < 0.001). Among patients who had previously taken DFO and were randomized to receive deferasirox during the study, 96.9% reported a preference for deferasirox over DFO. At EOS, the proportion of patients indicating a willingness to continue study therapy was significantly greater in those receiving deferasirox than in those receiving DFO (85.8% vs 13.8%; P < 0.001). Conclusions: In this study, patient-reported satisfaction and convenience were significantly higher for the once-daily, oral ICT deferasirox than for DFO infusions. Among patients who had received DFO before the study, the majority indicated a preference for deferasirox over DFO. Most patients receiving deferasirox indicated that they would be willing to continue taking it. These results suggest that deferasirox had a positive impact on patients' daily lives.

Inherited bone marrow failure syndromes are a group of rare, heterogeneous genetic disorders with a risk of clonal and malignant myeloid transformation including clonal marrow cytogenetic abnormalities, myelodysplastic syndrome and acute myeloid leukemia. The clinical characteristics, risk classification, prognostic factors and outcome of clonal and malignant myeloid transformation associated with inherited bone marrow failure syndromes are largely unknown. The aims of this study were to determine the impact of category, cytopathology and cytogenetics, the three components of the “Category Cytology Cytogenetics” classification of pediatric myelodysplastic syndrome, on the outcome of clonal and malignant myeloid transformation associated with inherited bone marrow failure. We used data from the Canadian Inherited Marrow Failure Registry. Among 327 patients with inherited bone marrow failure syndrome enrolled in the registry, the estimated risk of clonal and malignant myeloid transformation by the age of 18 years was 37%. The risk of clonal and malignant myeloid transformation varied according to the type of inherited bone marrow failure syndrome but was highest in Fanconi anemia. The development of clonal and malignant myeloid transformation significantly affected overall survival. Mortality varied based on cytopathological group. The largest group of patients had refractory cytopenia. Clonal marrow cytogenetic abnormalities were identified in 87% of patients with clonal and malignant myeloid transformation, and different cytogenetic groups had different impacts on disease progression. We conclude that category, cytopathology and cytogenetics in cases of clonal and malignant myeloid transformation associated with inherited bone marrow failure syndromes have an important impact on outcome and that the classification of such cases should incorporate these factors.

BACKGROUND: Cisplatin (Cis), carboplatin (Carb), and ifosfamide (Ifos) are common nephrotoxic chemotherapies. Biomarkers of tubular injury may allow for early acute kidney injury (AKI) diagnosis. PROCEDURE: We performed a two-center (Canada, United States) pilot study to prospectively measure serum creatinine (SCr), urine neutrophil gelatinase-associated lipocalin (NGAL), and interleukin-18 (IL-18) in children receiving Cis/Carb (27 episodes), Ifos (30 episodes), and in 15 hospitalized, nonchemotherapy patients. We defined AKI using the Kidney Disease Improving Global Outcomes (KDIGO) definition. We compared postchemotherapy infusion NGAL and IL-18 concentrations (immediate postdose to 3 days later) to pre-infusion concentrations. We calculated area under the receiver operating characteristic curve (AUC) for postinfusion biomarkers to discriminate for AKI. RESULTS: Prechemotherapy infusion NGAL and IL-18 concentrations were not higher than nonchemotherapy control concentrations. Increasing chemotherapy dose was associated with increasing postinfusion (0–4 hr after infusion) NGAL (P < 0.05). Post-Ifos, immediate postdose, and daily postdose NGAL and IL-18 were significantly higher than pre-infusion biomarker concentrations (P < 0.05), during AKI episodes. NGAL and IL-18 did not rise significantly after Cis–Carb infusion, relative to predose concentrations (P > 0.05). NGAL and IL-18 measured immediately after Ifos infusion discriminated for AKI with AUCs is 0.80 (standard error = 0.13) and 0.73 (standard error = 0.16), respectively. NGAL and IL-18 were not diagnostic of Cis–Carb-associated AKI. When AUCs were adjusted for age, all biomarker AUCs (Cis–Carb and Ifos) improved. CONCLUSION: Urine NGAL and IL-18 show promise as early AKI diagnostic tests in children treated with ifosfamide and may have a potential role in drug toxicity monitoring.

Increased requirement for central venous catheter replacement in paediatric oncology patients with deep venous thrombosis: A multicentre study

We report a case of bone pain associated with primary hyperparathyroidism in a patient with sickle cell disease. A 17-year-old girl with sickle cell disease (SS phenotype) was seen for bilateral knee and back pain. She had had recurrent severe vaso-occlusive crises and acute chest syndrome in the course of her disease. In the last 2 years, she had frequent visits to the emergency department for severe bone pain. She complained of long-standing fatigue and lethargy. Her physical examination was normal. Hydroxyurea treatment, as well as and long- and short-acting narcotics were given, with little improvement in symptoms. Poor compliance with medication, family dysfunction, and potential narcotic addiction were felt to be significant contributors to the patient's symptoms. She was incidentally found to have an extremely elevated total calcium level of 3.19 mmol/L (range: 2.25–2.76) with an ionized calcium level of 1.9 mmol/L (range: 1.15–1.35). Phosphorus level was 0.82 mmol/L (range: 0.90–1.50), alkaline phosphatase level was elevated at 519 U/L (range: 10–170), and parathyroid hormone level was extremely high at 1645 pg/mL (range: 10–60). Her renal function was normal. Ultrasonography of the neck and a Sestamibi scan revealed a single left inferior parathyroid adenoma adjacent to the thyroid lobe. There was no evidence of an underlying multiple endocrine neoplasia. The patient was diagnosed with primary hyperparathyroidism. Fluid hydration, hydrocortisone, calcitonin, and bisphosphonates were initiated for acute hypercalcemia management before surgical excision of the left parathyroid adenoma. On review of previous blood work, a borderline calcium level of 2.72 was present 18 months before this admission. Two years postsurgery, she has normal renal function, calcium, and parathyroid hormone levels. The weekly visits to the emergency department for pain episodes decreased to 1 every 2 months within the first few months after her surgery. The decrease in pain episodes, even if it coincided with the treatment of primary hyperparathyroidism, may still reflect the natural evolution of sickle cell disease in this patient. However, the high morbidity associated with primary hyperparathyroidism was successfully prevented in this patient. Primary hyperparathyroidism is rare in childhood. In a recent study, it occurred more commonly in female adolescents and was because of a single adenoma, as in our patient. Significant morbidity, mainly secondary to renal dysfunction, was because of the delay in diagnosis after the onset of symptoms (2.0–4.2 years), emphasizing the need for a rapid diagnosis. Sickle cell disease affects ∼1 of every 600 blacks in North America. Acute episodes of severe vaso-occlusive crisis account for >90% of sickle cell-related hospitalizations and are a significant cause of morbidity in patients. There is no known association between sickle cell disease and primary hyperparathyroidism, and this case is most probably a random occurrence. However, as emphasized by this case report, pain may also be a harbinger of other disease processes in sickle cell disease. Because management may vary, we suggest that care providers consider the diagnosis of vaso-occlusive crisis as the diagnosis of exclusion and that other etiologies for pain be envisaged in this patient population, especially in the presence of prolonged pain or unusual clinical, radiologic, or biological findings.

Constipation is a common problem in pediatric oncology patients and may lead to significant consequences. There is a paucity of the published literature on the prevention of constipation in this population. The primary purpose of this study was to explore the current practice of pediatric oncologists in preventing constipation in children receiving active chemotherapy treatment, specifically during periods of intensive vincristine therapy.A Web-based survey of pediatric oncologists and pediatric oncology trainees in Canadian centers was conducted.A 48% response rate was achieved. The majority of physicians had a lower threshold for defining constipation in oncology patients compared with the published literature. More than 90% of the respondents estimated the prevalence of constipation in pediatric oncology patients to be 30% or higher. The majority of respondents prescribed constipation prophylaxis in the presence of one or more of the following factors: history of constipation prior to or during previous phases of therapy, vincristine combined with either narcotics or immobility, multiple vincristine doses per month, spinal cord compression and immobility, and isolated narcotic therapy. Polyethylene glycol 3350, lactulose, and ducosate were the most commonly recommended first-line prophylactic therapies used.Constipation is a significant problem in patients during cancer treatment. Most oncologists suggest giving laxatives as prophylaxis in the presence of risk factors, as well as prompt treatment once any symptoms appear. Our results suggest a role for the introduction of guidelines in the prevention of constipation, especially for patients receiving frequent vincristine therapy.

We report on a child with microcephaly, small facial and body size, and immune deficiency. The phenotype is consistent with Nijmegen breakage syndrome (NBS), with additional clinical manifestations and laboratory findings not reported heretofore. Most investigations, including the results of radiation-resistant DNA synthesis, concurred with the diagnosis of NBS. Cytogenetic analysis documented abnormalities in virtually all cells examined. Along with the high frequency of breaks and rearrangements of chromosomes 7 and 14, we found breakage and monosomies involving numerous other chromosomes. Because of some variation in the clinical presentation and some unusual cytogenetic findings, we suggest that our patient may represent a new variant of Nijmegen breakage syndrome.

Individuals with severe forms of congenital neutropenia suffer from recurrent infections. The therapeutic use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) to increase the neutrophil count is associated with fewer infections and an improved quality of life. However, the long-term effects of this new therapy are largely unknown. In particular, it is unclear if myeloid leukemia, a known complication of some forms of congenital neutropenia, will occur with increased frequency among patients who receive long-term treatment with hematopoietic growth factors. We report 13 patients with congenital disorders of myelopoiesis who developed leukemic transformation with either myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML) and 1 who acquired a clonal cytogenetic abnormality without evidence of MDS or AML while receiving rhG-CSF. The bone marrows of 10 patients showed monosomy 7 and 5 had activating RAS mutations. These abnormalities were not detected in pretreatment bone marrows and cessation of rhG-CSF was not associated with either clinical improvement or cytogenetic remission. We conclude that patients with severe forms of congenital neutropenia are at relatively high risk of developing MDS and AML. The occurrence of monosomy 7 and RAS mutations in these cases suggests that the myeloid progenitors of some patients are genetically predisposed to malignant transformation. The relationship between therapeutic rhG-CSF and leukemogenesis in patients with severe chronic neutropenia is unclear.

BackgroundAdrenal suppression (AS) is an under-recognised side effect of glucocorticoid (GC) use. AS may go undetected until a physiological stress precipitates an adrenal crisis. The incidence of AS has not been established. We sought to estimate the minimum national incidence and presenting features of paediatric symptomatic AS.MethodsThrough the established methodology of the Canadian Paediatric Surveillance Program, over 2500 paediatricians were surveyed monthly for 2 years (April 2010–March 2012) to report new cases of symptomatic AS.ResultsForty-six cases of symptomatic AS were confirmed. The estimated annual incidence is 0.35/100 000 children aged 0–18 years (95% CI 0.26 to 0.47). The most common presentations were growth failure (35%), non-specific symptoms (28%) or both (13%). Adrenal crisis occurred in six cases (13%). Thirty-seven children (80%) had received inhaled corticosteroid (ICS) alone or in combination with other GC forms. Many children received high but commonly prescribed doses of ICS.ConclusionsAS is responsible for significant morbidity in children, including susceptibility to adrenal crisis. The minimal estimated incidence reported is for the entire paediatric population and would be much higher in the at-risk group (ie, children treated with GCs). Close monitoring of growth and possible symptoms of AS, which may be non-specific, are important in children on all forms of GC therapy including ICS. To reduce the risk of AS, physicians must be aware of the risk of AS, revisit GC doses frequently and use the lowest effective dose.

Background. Inherited bone marrow failure syndromes (IBMFSs) comprise a genetically heterogeneous group of diseases with hematopoietic failure and varying degrees of physical malformations. The diagnosis of an IBMFS and categorizing the specific syndrome critically impact on clinical care; however, these are commonly challenging and rely on genetic testing. Since over 80 genes have been associated with IBMFSs and might be affected by different types of DNA aberrations, the best strategy to establish a diagnosis in a timely and cost effective manner is unknown. The aims of this study were to evaluate the role of genome-wide copy number variant (CNV) analysis in unraveling causal genetic alterations in IBMFS patients with unknown genotype and determine whether correlation exists between large CNVs and more severe phenotype. Methods. Patients from the Canadian Inherited Marrow Failure Registry (CIMFR) who were genetically investigated were included in this analysis. Genetic and clinical data were extracted and analyzed. Mann-Whitney test and Fisher's exact test were used to assess statistical significance. Results. Among 328 patients from the CIMFR who underwent molecular investigation, a causal genotype was identified in 185 cases (56.4%). 69 patients had genome-wide CNV analysis by SNP/CGH arrays, among which ten (14.5%) had positive results. In four out of ten cases who were genotyped by SNP/CGH array, genome-wide CNV analysis was critical for establishing the diagnosis. Among 308 patients who were tested for nucleotide-level mutations by either targeted gene analysis or next generation sequencing panels, casual mutations were found in 169 (54.9%). Three patients had compound heterozygosity for a CNV and nucleotide-level mutation. To determine whether large deletions are correlated with more severe phenotype we included nine additional patients with causal CNVs whose genotype was identified by MLPA (n=1), targeted FISH (n=1), DNA-qPCR analysis (n=1), Southern blotting (n=1) or metaphase cytogenetics (n=5). The causal CNVs among patients in our cohort ranged from 0.02 to 145.5 Mb in size. The most common disease associated with causal CNVs was Diamond-Blackfan anemia (four patients). Patients with CNVs tended to have significantly more non-hematological organ system involvement (p=0.03), developmental delay (mean=56% vs. 28%, p=0.03) and short stature (mean=67% vs. 40%, p=0.04) than patients with nucleotide-level mutations. The difference remained significant when we compared all patients with mutations that are predicted to result in truncation or lack of protein from the respective allele (large CNV, nonsense, and indel/ frameshift) to patients with mutations that are predicted to be hypomorphic or affect function (splicing, indel/ inframe and missense). There was no correlation between CNVs and the severity of the hematological disease. Conclusions. Most patients with IBMFSs have nucleotide-level mutations. However, a significant proportion of patients without such mutations have large CNVs that are not efficiently detected by current nucleotide-level testing methods. Therefore, genome-wide CNV analysis should be considered in IBMFS cases, where nucleotide-level sequencing does not reveal the causal mutation. Patients with IBMFSs and large CNVs had more non-hematological organ system involvement, a higher prevalence of developmental delay and short stature. This might be related to an additional impact of the CNVs on other genes close to the affected IBMFS gene or the severe damaging effect of the CNVs. Disclosures Lipton: Teva: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Novartis Pharmaceuticals: Consultancy, Research Funding.

Background/Objectives: Diamond Blackfan anemia (DBA) is an inherited disorder characterized by chronic hypoproductive anemia, physical malformations, and an increased risk of malignancies. At least 12 DBA genes have been identified, which include various ribosomal protein genes and the transcription factor GATA1. The aims of our study were (1) to identify the mutation spectrum of DBA patients, utilizing a cohort of patients enrolled on the Canadian Inherited Marrow Failure Registry (CIMFR) and (2) to determine whether specific hematological abnormalities, malformations, and outcomes are associated with specific mutations. Methods: Patients were enrolled on the CIMFR, which is a multicenter cohort study of inherited bone marrow failure syndromes (IBMFS). Genetic testing was performed using one or more of the following tests: Sanger sequencing, next generation sequencing (NGS) DBA gene panel, a comprehensive NGS IBMFS gene panel developed in our laboratory, or comparative genetic hybridization (CGH). Severity of the hematological disease was dichotomized according to a patient's requirement for chronic treatment: those who were maintained on corticosteroids, blood transfusions, or received a hematopoietic stem cell transplantation were considered to have a more severe phenotype than those who did not require hematological treatment. Chi-square tests with a Fisher's exact test correction were used to compare genetic groups with at least 5 patients on observed phenotypes. Results: 71 patients with DBA have been enrolled in our registry. A causal mutation has been identified in 36 of these patients, with the following rates: RPS19 (n=11), RPL11 (n=7), RPL5 (n=6), RPS26 (n=5), RPL35a (n=2), RPS24 (n=2), and one of each RPS7, RPS29, RPS17. Remarkably, a substantial number of patients in our population-based cohort (19.4%) had mild hematological phenotype requiring no therapy. Patients with RPL11 mutations tended to have a less severe DBA phenotype, while patients with RPS19 mutations tended to have a more severe phenotype (p=0.04). In terms of non-hematological malformations, we found no differences in cardiac, stature and craniofacial malformations across the groups compared (all p>0.1). However, patients with RPL5 mutations had significantly more hand malformations (p=0.02), and patients with RPS26 mutations had more genitourinary malformations (p=0.04). To control for the impact of mutation severity on the observed phenotype, we compared the prevalence of mutations that are predicted to result in truncated or lack of protein from the respective allele (large copy-number variation, nonsense, or indel frameshift) to mutations that are predicted to be hypomorphic or affect function (splicing, indel/inframe and, missense) between mutation categories. There were no differences among genetic groups in the severity of their mutations (p=0.58). Conclusions: Mutations in a wide spectrum of ribosomal protein genes underlie DBA cases in Canada, which approximate those observed by other registries in Western countries. Patients with DBA caused by RPL11 mutations tended to have a milder hematological phenotype, while patients with RPS19 mutation tended to have a more severe phenotype. Mutations in RPS26 and RPL5 are associated with genitourinary and hand malformations, respectively. Our findings may help improve counseling of DBA patients and their family. Future studies are needed to replicate our results and determine whether these findings can help personalize care. Disclosures Lipton: Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Novartis Pharmaceuticals: Consultancy, Research Funding.

Introduction Inherited bone marrow failure syndromes (IBMFSs) often have substantial phenotypic overlap, thus genotyping is often critical for establishing a diagnosis. Objectives and methods To determine the genetic characteristics and mutation profiles of IBMFSs, a comprehensive population-based study that prospectively enrols all typical and atypical cases without bias is required. The Canadian Inherited Marrow Failure Study is such a study, and was used to extract clinical and genetic information for patients enrolled up to May 2010. Results Among the 259 primary patients with IBMFS enrolled in the study, the most prevalent categories were DiamondeBlackfan anaemia (44 patients), Fanconi anaemia (39) and ShwachmaneDiamond syndrome (35). The estimated incidence of the primary IBMFSs was 64.5 per 10 6 births, with Fanconi anaemia having the highest incidence (11.4 cases per 10 6 births). A large number of patients (70) had haematological and non-haematological features that did not fulfil the diagnostic criteria of any specific IBMFS category. Disease-causing mutations were identified in 53.5% of the 142 patients tested, and in 16 different genes. Ten novel mutations in SBDS, RPL5, FANCA, FANCG, MPL and G6PT were identified. The most common mutations were nonsense (31 alleles) and splice site (28). Genetic heterogeneity of most IBMFSs was evident; however, the most commonly mutated gene was SBDS ,f ollowed byFANCA and RPS19. Conclusion From this the largest published comprehensive cohort of IBMFSs, it can be concluded that recent advances have led to successful genotyping of about half of the patients. Establishing a genetic diagnosis is still challenging and there is a critical need to develop novel diagnostic tools.

Our knowledge of the phenotypes of inherited bone marrow failure syndromes (IBMFSs) derives from case reports or case series in which only one IBMFS was studied. However, the substantial phenotypic overlap necessitates comparative analysis between the IBMFSs. Shwachman-Diamond syndrome (SDS) is an IBMFS that the appreciation of what comprises its clinical phenotype is still evolving. In this analysis we used data on 125 patients from the Canadian Inherited Marrow Failure Study (CIMFS), which is a prospective multicenter population-based study. Thirty-four cases of SDS patients were analyzed and compared to other patients with the four most common IBMFSs on the CIMFS: Diamond Blackfan anemia, Fanconi anemia (FA), Kostmann/severe congenital neutropenia and dyskeratosis congenita (DC). The diagnosis of SDS, FA and DC was often delayed relative to symptoms onset; indicating a major need for improving tools to establish a rapid diagnosis. We identified multiple phenotypic differences between SDS and other IBMFSs, including several novel differences. SBDS biallelic mutations were less frequent than in previous reports (81%). Importantly, compared to patients with biallelic mutations, patients with wild type SBDS had more severe hematological disease but milder pancreatic disease. In conclusion, comprehensive study of the IBMFSs can provide useful comparative data between the disorders. SBDS-negative SDS patients may have more severe hematological failure and milder pancreatic disease.

Background:. Inherited bone marrow failure syndromes (IMFSs) are genetic disorders characterized by defective single-lineage or multi-lineage hematopoiesis. IMFS patients are at risk for severe cytopenias, development of marrow cytogenetic abnormalities (MCA), myelodysplasia (MDS), and malignancy. The rate of disease progression and proportion of patients at risk for these complications is currently unclear. We examined recently diagnosed IMFS patients to determine distribution of diagnoses, disease progression and development of significant outcomes. Methods:. The CIMFR is a prospective multi-center study established in 2001 to register all IMFS patients in Canada. Analysis was restricted to patients diagnosed after November 30, 1997. Summary statistics were used to depict the study population while survival was described using the Kaplan‐Meier method. Results:. 74 CIMFR patients were considered recently diagnosed. Median age at diagnosis was 2.7 years (range, birth to 40.6). Annual follow-up data were available for 53 (72%) patients. The five most prevalent diagnoses were Fanconi anemia (FA), Shwachman‐Diamond syndrome (SDS), Diamond‐Blackfan anemia (DBA), dyskeratosis congenita (DKC), and Kostmann’s neutropenia (KS). Eighteen (24%) patients were unclassifiable. Twenty-eight (53%) follow-up patients had disease progression as indicated by new or worsening cytopenias, new marrow changes, or initiation of transfusion support and/or medical therapy. Fourteen (19%) fulfilled minimal diagnostic criteria for myelodysplasia. Eleven patients had hematopoietic stem cell transplantation (HSCT) by first follow-up. Five patients have died. Survival at 36 months is 89.8 � 5.7%. Conclusions:. IMFS patients are often diagnosed at a young age. The relative distribution of diagnoses is similar to previous reviews of published cases; however, 25% of patients are currently unclassifiable. Disease progression has occurred in approximately 50% of follow-up patients. Early mortality is noted. Continued prospective observation of these patients is warranted. Pediatr Blood Cancer 2006;47:918‐925. 2006 Wiley-Liss, Inc.

Introduction: Inherited bone marrow failure syndromes (IBMFS) are characterized by single or multi-lineage cytopenias as well as non-hematologic manifestations. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for the hematological abnormalities. However, high rates of mortality and morbidity from this procedure have been reported in patients with IBMFSs. Objective: The study aim was to investigate the impact of patient, donor and treatment-related variables on the outcome of HSCT in IBMFS patients. Methods: Data of patients who were prospectively enrolled in the Canadian Inherited Marrow Failure Registry (CIMFR) from 2001 to 2012 and underwent HSCT were analyzed. The CIMFR is a population-based multicenter study, which includes all 16 pediatric tertiary care centers across all provinces in Canada. These centers care for >95% of the eligible pediatric IBMFS population in Canada. Descriptive analyses, as well as univariate and multivariate analyses (using a Cox proportional hazards model) were performed to assess the impact of multiple factors on probability of survival following transplant. Results: Among 363 patients enrolled in CIMFR, 65 underwent allogeneic HSCT. Thiry-four patients were male and 30 were female (gender unknown for 1 patient). Median age at diagnosis with IBMFS was 3.0 years (range: prenatal diagnosis to 32.0 years) and median age at HSCT was 6.5 years (range: 0.25-20.1 years). Median follow-up time post-HSCT (time to death or last follow-up) was 2.8 years (range 0.01–15.9 years). Indications for transplant included severe cytopenia (n=44), myelodysplastic syndrome (n=18) acute myeloid leukemia (n=2) and unavailable cause (n=1). Cell type were bone marrow (n=40), cord blood (n=17), peripheral blood (n=5), unknown (n=3). Sixty-two percent of patients (n=40) received cells from an unrelated donor. Seventy-four percent (n=47) of patients had a full HLA-matched donor; 19 of those were related and 28 were unrelated donors. The most common conditioning regimen combined high dose cyclophosphamide, fludarabine and anti-thymocyte globulin (n=17). Incidence of graft failure, acute (grade II-IV) graft versus host disease (GVHD) and chronic GVHD was 14%, 30% and 22%, respectively. Five-year probability of survival for HSCT recipients was 73.4% ± 6.1% (SE). Causes of death included infections (CMV, fungal infections and bacterial), GVHD, lymphoproliferative disorder and congestive heart failure, pulmonary fibrosis, bronchiolitis obliterans. In the univariate analysis, factors significantly associated with increased mortality post-HSCT included ≥20 pre-HSCT platelet transfusions, pre-transplant administration of granulocyte colony-stimulating factor, 1 or more HLA mismatches, donor type (divided into four categories: matched related, partially matched related, matched unrelated, partially matched unrelated) and conditioning regimens combining high doses of cyclophosphamide with fludarabine and anti-thymocyte globulin (while comparing this combination against all others). The former 3 variables remained significant in the multivariate analysis. Conclusion: Number of pre-transplant platelet transfusions, use of granulocyte colony-stimulating factor and one or more donor-recipient HLA mismatches were shown to increase the risk of mortality in patients with IBMFSs undergoing HSCT. Novel strategies are needed to improve outcome in patients with a high risk of HSCT-related complications. Disclosures No relevant conflicts of interest to declare.

Background and Objectives. Phenotypic overlap among the inherited bone marrow failure syndromes (IBMFSs) frequently limits the ability to establish a diagnosis based solely on clinical manifestations. Since a large number of IBMFS genes (>70) have been identified, genetic testing is often prolonged and costly. Correct diagnosis, care and counseling often depend on identifying the mutated gene. Thus time-efficient and cost-effective strategies for genetic testing are essential. The aims of this study were to develop and evaluate the application of a next generation sequencing (NGS) IBMFS Gene Panel assay for genetic testing of patients with previously characterized categories of IBMFSs (e.g. Fanconi anemia and Diamond Blackfan anemia) but unknown genotype, as well as patients with unclassified IBMFSs. Methods. We designed a NGS assay to test a comprehensive panel of 72 known IBMFS genes. Genomic DNA from patients enrolled on the Canadian Inherited Marrow Failure Registry was analyzed using the Haloplex technology and Illumina Seq2000 platform. The average gene coverage was 99.12%. SureCall program was used to align, map, and identify variants. Polyphen, Sift and MutationTaster were used to predict the effect of variants on the protein. Human Splicing Finder program was used to analyze effect of splicing. The assay was validated by detecting all 50 mutations and polymorphic variants that were previously found by Sanger sequencing in 31 patients. Results. A total of 158 patients with unknown mutations were studied. Among 75 patients with known categories of IBMFSs but unknown genotypes, we found deleterious mutations in 43 patients (57.3%). These categories included Diamond Blackfan anemia, Fanconi anemia, dyskeratosis congenita, Shwachman-Diamond syndrome, TAR syndrome, familial thrombocytopenia and Kostmann/severe congenital neutropenia. Among 83 patients with unclassified IBMFSs, we found deleterious mutations and established the diagnosis in 16 patients (19.2%). Established diagnoses included dyskeratosis congenita, Diamond-Blackfan anemia, myelokathexis, GATA2-associated familial MDS, WAS-associated severe congenital neutropenia, G6PC3-associated severe congenital neutropenia, MYH9-associated disorder, MASTL-associated disorder and Wiskott-Aldrich syndrome. All identified mutations were validated. The assay allowed identification of mutant genes that had not been previously reported to be associated with the patient phenotypes in two cases. The assay led to amendment of established diagnoses in two other cases. The assay results directed a change in clinical care in multiple cases, including implementation of cancer surveillance program and consideration for prenatal diagnosis. The cost of the NGS was $470/patient compared to $4643/patient among those who underwent genetic testing by Sanger sequencing during the tenure of the study. Conclusion. Our novel assay is a rapid, accurate, and cost saving strategy for genetic investigation of patients with IBMFSs. It can identify mutations in classified and unclassified IBMFSs with high level of sensitivity and precision. Disclosures No relevant conflicts of interest to declare.

3400 Background: Central venous catheters (CVCs) have greatly improved the delivery of systemic chemotherapy to pediatric oncology patients and have significantly improved their quality of life. However, CVCs can cause serious venous thrombotic events (VTE), necessitating anticoagulation, CVC removal and reinsertion. There is paucity of data on clinical manifestations and impact of CVC associated VTE in pediatric cancer patients. In this study we describe the clinical presentation and impact of VTE on CVCs. Methods: We performed a multi-center case-control study in childhood cancer survivors. Survivors who experienced a symptomatic VTE during their therapy, and survivors who did not experience VTE (controls) were recruited. Additionally, controls in whom an asymptomatic VTE was detected were assessed separately. Data on location and number of CVCs and of VTE was analyzed. CVCs were categorized by method of insertion and included totally implanted devices (TID) such as ports, tunneled lines (TL) and peripherally insertion central catheters (PICC). Results: Seventy-seven survivors with a history of symptomatic VTE, 10 with asymptomatic VTE, and 178 controls were recruited ([Table 1][1]). The mean number of CVCs per individual cases and controls was 1.64±0.91 and 1.12±0.55, respectively (p=0.0001). In cases and controls, 44% and 12.3%, respectively, had >1 CVC (p=0.0001). In patients with asymptomatic VTE the mean number of CVCs per individual was 1.8±1.03 (p=0.069, tending towards significance as compared to controls); 50% had >1 CVC. Among cases with symptomatic VTE, right subclavian (RSCV) (35.1%), left subclavian (LSCV) (16.9%) and right internal jugular (RIJ) (14.3%) veins were the most common CVC sites. In controls, corresponding percentages were 32.6%, 20.8% and 9.6%, respectively. In patients with asymptomatic VTE, RIJ (40%) and RSCV (20%) were the most frequent CVC sites. TID, TL and PICC were used in 60.7%, 22.5% and 2.3% of the controls, respectively. The corresponding numbers in symptomatic VTE cases were 52%, 22.1% and 11.7%, respectively. The difference in distribution of CVCs in the 2 groups was statistically significant (p=0.017). TID were used more frequently in controls (60.7%) as compared to symptomatic VTE (52%) patients. Central venous catheters were inserted into the right-sided veins in 57.9%, 65% and 80% of the controls, symptomatic and asymptomatic VTE cases, respectively. Forty-nine patients had central venous VTE (CVVTE). CVC dysfunction (46.9%), swelling (34.7%) and pain (14.3%) were the most common symptoms of CVVTE. TID, TL and PICC were used in 50%, 34.8% and 6.5%, respectively, of the patients with CVVTE. Concordance in the location of CVC and CVVTE was seen in 27 (55.1%) cases. The most common sites of CVCs in these 27 patients were RIJ (25.9%), RSCV (25.9%) and LSCV (18.5%). Conclusions: In this cohort of pediatric cancer survivors, we made several novel observations indicating significant clinical impact of both symptomatic and asymptomatic VTE. The type of CVC used varied significantly between cases and controls. Use of TID appears protective, plausibly due to relatively shorter length of the central line (compared to other CVCs), non-exposed parts, and use of only non-coring needles to access the device. A concordance of over 50% in the location of CVCs and that of CVVTE was observed and has not previously been reported. These observations are of importance in identification of pediatric oncology patients at higher risk of CVC related complications. These observations can inform the design of appropriate preventive and therapeutic interventions in pediatric oncology patients who will continue to require CVCs. | Parameters | Symptomatic VTE (77) | Controls (178) | p value[*][2] | Asymptomatic VTE (10) | |:--------------------:| -------------------- | -------------- | ------------- | ------------------------- | | CVC (mean) | 1.64±0.91 | 1.12±0.55 | 0.0001 | 1.8±1.03 (p[**][3]=0.069) | | Patients with >1 CVC | 42.8% (33) | 11.8% (21) | 0.0001 | 50% (5) | | Location of CVC | | | | | | RIJ | 14.3% (11) | 9.6% (17) | – | 40% | | LIJ | 2.6% (2) | 2.3% (4) | | | RSCV | 35.1% (27) | 32.6% (58) | 20% | | LSCV | 16.9% (13) | 20.8% (37) | | | Others | 31.2% (24) | 34.8% (62) | 40% | | Type of CVC | | | | | | PICC | 11.7% (9) | 2.3% (4) | 0.017 | 10% | | TL | 22.1% (17) | 22.5% (40) | 40% | | TID | 52% (40) | 60.7% (108) | 40% | | Others | 7.8% (6) | 6.2% (11) | 10% | | Side of CVC | | | | | | Right | 65% (50) | 57.9% (103) | 0.223 | 80% | | Left | 23.4% (18) | 25.8% (46) | – | | Central | 7.8% (6) | 2.8% (5) | 10% | * Numbers in parenthesis indicate patient numbers, * [↵][4]* for comparison between symptomatic VTE and controls, * [↵][5]** comparison with controls. Table 1. Characteristics of the study patients Disclosures: No relevant conflicts of interest to declare. [1]: #T1 [2]: #fn-2 [3]: #fn-3 [4]: #xref-fn-2-1 [5]: #xref-fn-3-1