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The underlying mechanisms of plasma metabolite signatures of human aging and age-related diseases are not clear but telomere attrition and dysfunction are central to both. Dyskeratosis congenita (DC) is associated with mutations in the telomerase enzyme complex (TERT, TERC, and DKC1) and progressive telomere attrition. We analyzed the effect of telomere attrition on senescence-associated metabolites in fibroblast-conditioned media and DC patient plasma. Samples were analyzed by gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. We showed extracellular citrate was repressed by canonical telomerase function in vitro and associated with DC leukocyte telomere attrition in vivo, leading to the hypothesis that altered citrate metabolism detects telomere dysfunction. However, elevated citrate and senescence factors only weakly distinguished DC patients from controls, whereas elevated levels of other tricarboxylic acid cycle (TCA) metabolites, lactate, and especially pyruvate distinguished them with high significance. The DC plasma signature most resembled that of patients with loss of function pyruvate dehydrogenase complex mutations and that of older subjects but significantly not those of type 2 diabetes, lactic acidosis, or elevated mitochondrial reactive oxygen species. Additionally, our data are consistent with further metabolism of citrate and lactate in the liver and kidneys. Citrate uptake in certain organs modulates age-related disease in mice and our data have similarities with age-related disease signatures in humans. Our results have implications for the role of telomere dysfunction in human aging in addition to its early diagnosis and the monitoring of anti-senescence therapeutics, especially those designed to improve telomere function.

Telomere biology disorders (TBDs) are a group of rare diseases caused by mutations that impair telomere maintenance. Mutations that cause reduced levels of TERC/hTR, the telomerase RNA component, are found in most TBD patients and include loss-of-function mutations in hTR itself, in hTR-binding proteins [NOP10, NHP2, NAF1, ZCCHC8, and dyskerin (DKC1)], and in proteins required for hTR processing (PARN). These patients show diverse clinical presentations that most commonly include bone marrow failure (BMF)/aplastic anemia (AA), pulmonary fibrosis, and liver cirrhosis. There are no curative therapies for TBD patients. An understanding of hTR biogenesis, maturation, and degradation has identified pathways and pharmacological agents targeting the poly(A) polymerase PAPD5, which adds 3'-oligoadenosine tails to hTR to promote hTR degradation, and TGS1, which modifies the 5'-cap structure of hTR to enhance degradation, as possible therapeutic approaches. Critical next steps will be clinical trials to establish the effectiveness and potential side effects of these compounds in TBD patients.

Despite the inclusion of inherited myeloid malignancies as a separate entity in the World Health Organization Classification, many established predisposing loci continue to lack functional characterization. While germline mutations in the DNA repair factor ERCC excision repair 6 like 2 (ERCC6L2) give rise to bone marrow failure and acute myeloid leukaemia, their consequences on normal haematopoiesis remain unclear. To functionally characterise the dual impact of germline ERCC6L2 loss on human primary haematopoietic stem/progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs), we challenged ERCC6L2-silenced and patient-derived cells ex vivo. Here, we show for the first time that ERCC6L2-deficiency in HSPCs significantly impedes their clonogenic potential and leads to delayed erythroid differentiation. This observation was confirmed by CIBERSORTx RNA-sequencing deconvolution performed on ERCC6L2-silenced erythroid-committed cells, which demonstrated higher proportions of polychromatic erythroblasts and reduced orthochromatic erythroblasts versus controls. In parallel, we demonstrate that the consequences of ERCC6L2-deficiency are not limited to HSPCs, as we observe a striking phenotype in patient-derived and ERCC6L2-silenced MSCs, which exhibit enhanced osteogenesis and suppressed adipogenesis. Altogether, our study introduces a valuable surrogate model to study the impact of inherited myeloid mutations and highlights the importance of accounting for the influence of germline mutations in HSPCs and their microenvironment.

Dyskeratosis congenita (DC) is a multisystem syndrome characterized by mucocutaneous abnormalities, bone marrow failure, and predisposition to cancer. Studies over the last 25 years have led to the identification of 18 disease genes. These have a principal role in telomere maintenance, and patients usually have very short/abnormal telomeres. The advances have also led to the unification of DC with a number of other diseases, now collectively referred to as the telomeropathies or telomere biology disorders.Clinical features, genetics, and biology of the different subtypes. Expert view on diagnosis, treatment of the hematological complications and future.As these are very pleotropic disorders affecting multiple organs, a high index of suspicion is necessary to make the diagnosis. Telomere length measurement and genetic analysis of the disease genes have become useful diagnostic tools. Although hematological defects can respond to danazol/oxymetholone, the only current curative treatment for these is hematopoietic stem cell transplantation (HSCT) using fludarabine-based conditioning protocols. New therapies are needed where danazol/oxymetholone is ineffective and HSCT is not feasible.

Biallelic germline ERCC6L2 variants strongly predispose to bone marrow failure (BMF) and myeloid malignancies characterized by somatic TP53-mutated clones and erythroid predominance. We present a series of 52 subjects (35 families) with ERCC6L2 biallelic germline variants collected retrospectively in 11 centers globally, including follow-up of 1165 person-years. At initial investigations, 32 individuals were diagnosed with BMF and 15 with a hematological malignancy (HM). Subjects presented with 19 different variants across ERCC6L2, and we identified a founder mutation c.1424delT in the Finnish patients. The median age of subjects at baseline was 18 years (range 2-65). Changes in complete blood count (CBC) were mild despite severe bone marrow hypoplasia and somatic TP53 mutations, with no significant difference between subjects with or without (HM). Signs of a progressive disease were increasing TP53 variant allele frequency, dysplasia in megakaryocytes and/or erythroid lineage, and erythroid predominance in bone marrow morphology. The median age at onset of HM was 37.0 years (95% CI: 31.5-42.5; range 12-65). Overall survival (OS) at 3 years was 95% (95% CI: 85-100) and 19% (95% CI: 0-39) for patients with BMF and HM, respectively. Patients with myelodysplastic syndrome or acute myeloid leukemia with mutated TP53 undergoing hematopoietic stem cell transplantation had a poor outcome: 3-year OS is 28% (95% CI: 0-61). Our results demonstrate the importance of early recognition and active surveillance of patients with biallelic germline ERCC6L2 variants.

Gene expression profiling has long been used in understanding the contribution of genes and related pathways in disease pathogenesis and susceptibility. We have performed whole-blood transcriptomic profiling in a subset of patients with inherited bone marrow failure (IBMF) whose diseases are clinically and genetically characterized as Fanconi anemia (FA), Shwachman-Diamond syndrome (SDS), and dyskeratosis congenita (DC). We hypothesized that annotating whole-blood transcripts genome wide will aid in understanding the complexity of gene regulation across these IBMF subtypes. Initial analysis of these blood-derived transcriptomes revealed significant skewing toward upregulated genes in patients with FA when compared with controls. Patients with SDS or DC also showed similar skewing profiles in their transcriptional status revealing a common pattern across these different IBMF subtypes. Gene set enrichment analysis revealed shared pathways involved in protein translation and elongation (ribosome constituents), RNA metabolism (nonsense-mediated decay), and mitochondrial function (electron transport chain). We further identified a discovery set of 26 upregulated genes at stringent cutoff (false discovery rate < 0.05) that appeared as a unified signature across the IBMF subtypes. Subsequent transcriptomic analysis on genetically uncharacterized patients with BMF revealed a striking overlap of genes, including 22 from the discovery set, which indicates a unified transcriptional drive across the classic (FA, SDS, and DC) and uncharacterized BMF subtypes. This study has relevance in disease pathogenesis, for example, in explaining the features (including the BMF) common to all patients with IBMF and suggests harnessing this transcriptional signature for patient benefit.

Dyskeratosis congenita (DC) is an inherited bone-marrow-failure disorder characterized by a triad of mucocutaneous features that include abnormal skin pigmentation, nail dystrophy, and oral leucoplakia. Despite the identification of several genetic variants that cause DC, a significant proportion of probands remain without a molecular diagnosis. In a cohort of eight independent DC-affected families, we have identified a remarkable series of heterozygous germline variants in the gene encoding thymidylate synthase (TYMS). Although the inheritance appeared to be autosomal recessive, one parent in each family had a wild-type TYMS coding sequence. Targeted genomic sequencing identified a specific haplotype and rare variants in the naturally occurring TYMS antisense regulator ENOSF1 (enolase super family 1) inherited from the other parent. Lymphoblastoid cells from affected probands have severe TYMS deficiency, altered cellular deoxyribonucleotide triphosphate pools, and hypersensitivity to the TYMS-specific inhibitor 5-fluorouracil. These defects in the nucleotide metabolism pathway resulted in genotoxic stress, defective transcription, and abnormal telomere maintenance. Gene-rescue studies in cells from affected probands revealed that post-transcriptional epistatic silencing of TYMS is occurring via elevated ENOSF1. These cell and molecular abnormalities generated by the combination of germline digenic variants at the TYMS-ENOSF1 locus represent a unique pathogenetic pathway for DC causation in these affected individuals, whereas the parents who are carriers of either of these variants in a singular fashion remain unaffected.

Significance Bone marrow failure (BMF) syndromes are inherited life-threatening conditions characterized by low blood cell production and predisposition to cancer. In this study we report a germ line frameshift variant in the Sp1 transcription factor in a family of patients with BMF and acute leukemia. Sp1 is ubiquitously expressed in human tissues and regulates transcription for blood cell lineage specification. Dissecting the molecular function of this SP1 variant revealed a hypermorphic effect, triggering superactivation of Sp1-mediated transcription in the patients’ blood. To our knowledge, this is the first report of a naturally occurring germ line variant in SP1 that alters transcriptional networks and disrupts hematopoiesis in humans., Inherited bone marrow failure (BMF) syndromes are a heterogeneous group of diseases characterized by defective hematopoiesis and often predisposing to myelodysplastic syndrome (MDS) and acute myelogenous leukemia. We have studied a large family consisting of several affected individuals with hematologic abnormalities, including one family member who died of acute leukemia. By whole-exome sequencing, we identified a novel frameshift variant in the ubiquitously expressed transcription factor specificity protein 1 (SP1). This heterozygous variant (c.1995delA) truncates the canonical Sp1 molecule in the highly conserved C-terminal DNA-binding zinc finger domains. Transcriptomic analysis and gene promoter characterization in patients’ blood revealed a hypermorphic effect of this Sp1 variant, triggering superactivation of Sp1-mediated transcription and driving significant up-regulation of Sp1 target genes. This familial genetic study indicates a central role for Sp1 in causing autosomal dominant transmission of BMF, thereby confirming its critical role in hematopoiesis in humans.

SUMMARYUnderlying mechanisms of plasma metabolite signatures of human ageing and age-related diseases are not clear but telomere attrition and dysfunction are central to both. Dyskeratosis Congenita (DC) is associated with mutations in the telomerase enzyme complex (TERT, TERC, DKC1) and progressive telomere attrition. We show extracellular citrate is repressed by canonical telomerase function in vitro and associated with DC leukocyte telomere attrition in vivo; leading to the hypothesis that altered citrate metabolism detects telomere dysfunction. However, citrate and senescence factors only weakly distinguished DC patients from controls, whereas other tricarboxylic acid cycle metabolites, lactate and especially pyruvate distinguished them with high significance, consistent with further metabolism of citrate and lactate in the liver and kidneys. Citrate uptake in certain organs modulates age-related disease in mice and our data has similarities with age-related disease signatures in humans. Our results have implications for the early diagnosis of telomere dysfunction and anti-senescence therapeutics.HighlightsExtracellular citrate is regulated by telomere function in vitro and in vivo.Dyskeratosis Congenita (DC) is a human disease characterized by systemic telomere attrition, which showed an age-related plasma energetic profile, distinct from age-related disease and that of centenarians.The DC profile strikingly out-performed senescence factors in discriminating DC from controls, and pyruvate associated with a low lactate:pyruvate ratio is potentially a useful and cheap minimally invasive diagnostic aid for DC and telomere dysfunction.Mechanistically DC systemic metabolism is indicative of a shift to reduced pyruvate dehydrogenase activity, glycolysis and/or increased citrate and lactate production followed by further metabolism in the kidneys and liver.

Telomere biology disorders are complex clinical conditions that arise due to mutations in genes required for telomere maintenance. Telomere length has been utilised as part of the diagnostic work-up of patients with these diseases; here, we have tested the utility of high-throughput STELA (HT-STELA) for this purpose. HT-STELA was applied to a cohort of unaffected individuals (n = 171) and a retrospective cohort of mutation carriers (n = 172). HT-STELA displayed a low measurement error with inter- and intra-assay coefficient of variance of 2.3% and 1.8%, respectively. Whilst telomere length in unaffected individuals declined as a function of age, telomere length in mutation carriers appeared to increase due to a preponderance of shorter telomeres detected in younger individuals (p p p

Inherited bone marrow (BM) failure syndromes are a diverse group of disorders characterized by BM failure, usually in association with ≥1 extrahematopoietic abnormalities. BM failure, which can involve ≥1 cell lineages, often presents in the pediatric age group. Furthermore, some children initially labeled as having idiopathic aplastic anemia or myelodysplasia represent cryptic cases of inherited BM failure. Significant advances in the genetics of these syndromes have been made, identifying more than 100 disease genes, giving insights into normal hematopoiesis and how it is disrupted in patients with BM failure. They have also provided important information on fundamental biological pathways, including DNA repair: Fanconi anemia (FA) genes; telomere maintenance: dyskeratosis congenita (DC) genes; and ribosome biogenesis: Shwachman-Diamond syndrome and Diamond-Blackfan anemia genes. In addition, because these disorders are usually associated with extrahematopoietic abnormalities and increased risk of cancer, they have provided insights into human development and cancer. In the clinic, genetic tests stemming from the recent advances facilitate diagnosis, especially when clinical features are insufficient to accurately classify a disorder. Hematopoietic stem cell transplantation using fludarabine-based protocols has significantly improved outcomes, particularly in patients with FA or DC. Management of some other complications, such as cancer, remains a challenge. Recent studies have suggested the possibility of new and potentially more efficacious therapies, including a renewed focus on hematopoietic gene therapy and drugs [transforming growth factor-β inhibitors for FA and PAPD5, a human poly(A) polymerase, inhibitors for DC] that target disease-specific defects.

The inclusion of familial myeloid malignancies as a separate disease entity in the revised WHO classification has renewed efforts to improve the recognition and management of this group of at risk individuals. Here we report a cohort of 86 acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) families with 49 harboring germline variants in 16 previously defined loci (57%). Whole exome sequencing in a further 37 uncharacterized families (43%) allowed us to rationalize 65 new candidate loci, including genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1 and SEC23B), reported in prior MDS/AML or inherited bone marrow failure series (DNAH9, NAPRT1 and SH2B3) or variants at novel loci (DHX34) that appear specific to inherited forms of myeloid malignancies. Altogether, our series of MDS/AML families offer novel insights into the etiology of myeloid malignancies and provide a framework to prioritize variants for inclusion into routine diagnostics and patient management., Familial myeloid malignancies have recently been classified as separate disease entities. Here, using whole-exome sequencing of affected pedigrees - the authors highlight genetic variants associated with these conditions.

Inherited bone marrow failure is caused by mutations in genes that are critical for normal cell development or intrinsic cell function. Because of the protean effects of the mutations, multi-organ involvement is common. Compromised growth and early senescence drive strong selective pressure to acquire oncogenic somatic abnormalities. Thus, testing should be performed on non-hematopoietic cells such as fibroblasts.

Biallelic variants in the ERCC excision repair 6 like 2 gene (ERCC6L2) are known to cause bone marrow failure (BMF) due to defects in DNA repair and mitochondrial function. Here, we report on eight cases of BMF from five families harboring biallelic variants in ERCC6L2, two of whom present with myelodysplasia. We confirm that ERCC6L2 patients' lymphoblastoid cell lines (LCLs) are hypersensitive to DNA-damaging agents that specifically activate the transcription coupled nucleotide excision repair (TCNER) pathway. Interestingly, patients' LCLs are also hypersensitive to transcription inhibitors that interfere with RNA polymerase II (RNA Pol II) and display an abnormal delay in transcription recovery. Using affinity-based mass spectrometry we found that ERCC6L2 interacts with DNA-dependent protein kinase (DNA-PK), a regulatory component of the RNA Pol II transcription complex. Chromatin immunoprecipitation PCR studies revealed ERCC6L2 occupancy on gene bodies along with RNA Pol II and DNA-PK. Patients' LCLs fail to terminate transcript elongation accurately upon DNA damage and display a significant increase in nuclear DNA-RNA hybrids (R loops). Collectively, we conclude that ERCC6L2 is involved in regulating RNA Pol II-mediated transcription via its interaction with DNA-PK to resolve R loops and minimize transcription-associated genome instability. The inherited BMF syndrome caused by biallelic variants in ERCC6L2 can be considered as a primary transcription deficiency rather than a DNA repair defect.

Congenital radioulnar synostosis (RUS) is a rare developmental abnormality involving fusion of the bones of the forearms (radius and ulna) preventing normal supination of the affected forearm and has been recognized in orthopaedic literature since the mid-1800s. It is apparent that there is a

Biallelic mutations in ERCC6L2 were first reported to cause bone marrow failure (BMF). Additionally, we recently described a strong predisposition to erythroid lineage-restricted acute myeloid leukemia (AML-M6). Today, 31 ERCC6L2-mutated cases have been reported. This study aims to further explore the clinical and molecular features, as well as outcomes, of the ERCC6L2 patients. By June 2021, we have gathered clinical and genetic characteristics of 46 subjects in 31 families with biallelic germ line ERCC6L2 mutations from Finland (n = 21), France (n = 8), Israel (n = 1), Sweden (n = 4), and referred to a center in the United Kingdom (n = 12). Extension of the data collection from additional countries is ongoing. According to our data, ERCC6L2-disease often presents first as mild and fluctuating cytopenias with underlying bone marrow (BM) hypoplasia. With increasing age, patients develop clonal hematopoiesis with somatic mutations in TP53, and ultimately myelodysplastic syndrome (MDS) leading to a very high-risk acute myeloid leukemia. The median age of the patients at first referral to a hematologist was 18 years (range 6-65 years old). Characteristic changes in complete blood count (CBC) were mild thrombocytopenia, leukopenia, and sometimes macrocytosis. In individual pediatric or adolescent cases, more pronounced pancytopenia has also been noted. Severe BM hypoplasia was detected in many patients despite only mild changes in the CBC indicating that examining the histology of the BM biopsy, in addition to BM aspirate and CBC, is crucial. Also spontaneous, possibly transient, recovery of CBC in a few patients has occurred. All but one patient above 10 years of age, and with data from somatic mutation analysis (n = 17), carried one to four somatic TP53 mutations in their bone marrow. Among the 46 subjects, nine have been diagnosed with MDS and nine with AML (six with The French-American-British subtype M6, erythroleukemia; three with non-specific subtypes). Interestingly, increased reticulin fibrosis in the BM has been identified in at least three out of nine patients with MDS. In the nine patients diagnosed with AML, the median age of the appearance of leukemia was 37 years (range 20-65). Characteristic of TP53-mutated AML, all leukemia patients had complex hematologic karyotype and have deceased, despite intensive therapy, within one year of diagnosis. Approximately half of the patients with ERCC6L2-disease have been identified in Finland. The great majority of the patients (20/21) carry the same biallelic ERCC6L2 mutation (NM_020207.7) c.1424delT (p.Ile475ThrfsTer36). None of the Finnish families (n = 14) are consanguineous, but according to them, the ancestries reside in North-Eastern Finland indicating a founder effect. A more detailed genealogical analysis is ongoing and we suggest ERCC6L2-disease to be added to the Finnish Disease Heritage as the first cancer predisposition syndrome. Like many of the conditions identified in genetic isolates, ERCC6L2-disease is not restricted to Finland. Thus the current global effort to define the phenotype, as well as further molecular studies, will bring guidance to clinicians for tailoring follow-up and therapies for patients with ERCC6L2-disease. As a novel entity in the field of inherited bone marrow syndromes, we want to increase the awareness of ERCC6L2 -disease and encourage clinics to integrate ERCC6L2 into their germ line testing. Disclosures Siitonen: celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; abbvie: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees; Brystol Myers Squibb: Consultancy; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Honoraria.

RNA modifications are emerging as key determinants of gene expression. However, compelling genetic demonstrations of their relevance to human disease are lacking. Here, we link ribosomal RNA 2'-O-methylation (2'-O-Me) to the etiology of dyskeratosis congenita. We identify nucleophosmin (NPM1) as an essential regulator of 2'-O-Me on rRNA by directly binding C/D box small nucleolar RNAs, thereby modulating translation. We demonstrate the importance of 2'-O-Me-regulated translation for cellular growth, differentiation and hematopoietic stem cell maintenance, and show that Npm1 inactivation in adult hematopoietic stem cells results in bone marrow failure. We identify NPM1 germline mutations in patients with dyskeratosis congenita presenting with bone marrow failure and demonstrate that they are deficient in small nucleolar RNA binding. Mice harboring a dyskeratosis congenita germline Npm1 mutation recapitulate both hematological and nonhematological features of dyskeratosis congenita. Thus, our findings indicate that impaired 2'-O-Me can be etiological to human disease.

Item does not contain fulltext Patient registries are instrumental for clinical research in rare diseases. They help to achieve a sufficient sample size for epidemiological and clinical research and to assess the feasibility of clinical trials. The European Society for Immunodeficiencies (ESID) registry currently comprises information on more than 25,000 patients with inborn errors of immunity (IEI). The prerequisite of a patient to be included into the ESID registry is an IEI either defined by a defect in a gene included in the disease classification of the international union of immunological societies, or verified by applying clinical criteria. Because a relevant number of patients, including those with common variable immunodeficiency (CVID), representing the largest group of patients in the registry, remain without a genetic diagnosis, consensus on classification of these patients is mandatory. Here, we present clinical criteria for a large number of IEI that were designed in expert panels with an external review. They were implemented for novel entries and verification of existing data sets from 2014, yielding a substantial refinement. For instance, 8% of adults and 27% of children with CVID (176 of 1704 patients) were reclassified to 22 different immunodeficiencies, illustrating progress in genetics, but also the previous lack of standardized disease definitions. Importantly, apart from registry purposes, the clinical criteria are also helpful to support treatment decisions in the absence of a genetic diagnosis or in patients with variants of unknown significance.

A substantial number of individuals with bone marrow failure (BMF) present with one or more extra-hematopoietic abnormality. This suggests a constitutional or inherited basis, and yet many of them do not fit the diagnostic criteria of the known BMF syndromes. Through exome sequencing, we have now identified a subgroup of these individuals, defined by germline biallelic mutations in DNAJC21 (DNAJ homolog subfamily C member 21). They present with global BMF, and one individual developed a hematological cancer (acute myeloid leukemia) in childhood. We show that the encoded protein associates with rRNA and plays a highly conserved role in the maturation of the 60S ribosomal subunit. Lymphoblastoid cells obtained from an affected individual exhibit increased sensitivity to the transcriptional inhibitor actinomycin D and reduced amounts of rRNA. Characterization of mutations revealed impairment in interactions with cofactors (PA2G4, HSPA8, and ZNF622) involved in 60S maturation. DNAJC21 deficiency resulted in cytoplasmic accumulation of the 60S nuclear export factor PA2G4, aberrant ribosome profiles, and increased cell death. Collectively, these findings demonstrate that mutations in DNAJC21 cause a cancer-prone BMF syndrome due to corruption of early nuclear rRNA biogenesis and late cytoplasmic maturation of the 60S subunit.

This research was originally published in Blood Online. Tummala, H., et al. (2018). "Homozygous OB-fold variants in telomere protein TPP1 are associated with dyskeratosis congenita–like phenotypes." Blood 132(12): 1349-1353. Title. Blood. Prepublished Sept 20 2018; DOI https://doi.org/10.1182/blood-2018-03-837799

Acute leukaemia: investigations - Platelet reactions and refractoriness - Prophylactic regimen for neutropenic patients - Guidelines for use of IV antibiotics in neutropenic patients - Treatment of neutropenic sepsis: source unknown - Treatment of neutropenic sepsis: source known/suspected - Prophylaxis for patients treated with purine analogues - Tumour lysis syndrome - Administration of chemotherapy - Antiemetics for chemotherapy - Intrathecal chemotherapy - Management of extravasation - Specific procedures after extravasation of cytotoxics commonly used in haematology - Anticoagulation therapy: heparin - Oral anticoagulation with VKA - Oral anticoagulation with NOAC - Management of needlestick injuries - Chemotherapy protocols - ABVD - BEACOPP/escalated BEACOPP - BEAM/LEAM - Bortezomib/dexamethasone - CHOP 21 and CHOP 14 - ChlVPP - CODOX-M/IVAC ± R - CTD and CTDa - DHAP ± R - ESHAP ± R - FC ± R - ICE ± R - Lenalidomide/dexamethasone - MPT - Mini-BEAM ± R - Nordic schedule (R-maxi-CHOP and R-high-dose cytarabine for MCL) - PMitCEBO - R-Bendamustine - R-CHOP - R-CVP and CVP - Rituximab: monotherapy and maintenance therapy - Stanford V

Acute myeloblastic leukaemia (AML) - Acute lymphoblastic leukaemia (ALL) - Chronic myeloid leukaemia (CML) - Chronic lymphocytic leukaemia (B-CLL) - Prolymphocytic leukaemia (PLL) - Hairy cell leukaemia and variant - Large granular lymphocyte leukaemia (LGLL) - Adult T-cell leukaemia-lymphoma (ATLL)

History taking in patients with haematological disease - Physical examination - Splenomegaly - Lymphadenopathy - Unexplained anaemia - Patient with elevated haemoglobin - Elevated white blood cell (WBC) count - Reduced WBC count - Elevated platelet count - Reduced platelet count - Easy bruising - Recurrent thromboembolism - Pathological fracture - Raised ESR - Serum or urine paraprotein - Anaemia in pregnancy - Thrombocytopenia in pregnancy - Prolonged bleeding after surgery - Positive sickle test (HbS solubility test)

Blood counts in children - Red cell transfusion and blood component therapy—special considerations in neonates and children - Polycythaemia in newborn and childhood - Neonatal anaemia - Anaemia of prematurity - Haemolytic anaemia in the neonate - Congenital red cell defects - Acquired red cell defects - Haemolytic disease of the newborn - Hyperbilirubinaemia - Neonatal haemostasis - Neonatal alloimmune thrombocytopenia - Congenital dyserythropoietic anaemias - Congenital red cell aplasia - Acquired red cell aplasia - Fanconi anaemia - Rare congenital marrow failure syndromes - Neutropenia in childhood - Disorders of neutrophil function - Childhood immune (idiopathic) thrombocytopenic purpura - Haemolytic uraemic syndrome - Childhood cancer and malignant blood disorders - Childhood lymphoblastic leukaemia - Childhood lymphomas - Childhood acute myeloid leukaemia - Childhood myelodysplastic syndromes and chronic leukaemias - Histiocytic syndromes - Haematological effects of systemic disease in children

Full blood count - Blood film - Plasma viscosity - ESR - Haematinic assays - Haemoglobin electrophoresis - Haptoglobin - Schumm’s test - Kleihauer test - Reticulocytes - Urinary haemosiderin - Ham’s test - Immunophenotyping - Cytogenetics - Human leucocyte antigen (HLA) typing

Assessing haemostasis - The coagulation system - Laboratory tests - Platelets - Bleeding - Bleeding: laboratory investigations - Bleeding: therapeutic products - von Willebrand disease - Haemophilia A and B - Rare congenital coagulation disorders - Congenital thrombocytopenias - Congenital platelet function defects - Congenital vascular disorders - Haemorrhagic disease of the newborn - Thrombocytopenia (acquired) - Specific thrombocytopenic syndromes - Disseminated intravascular coagulation - Liver disease - Renal disease - Acquired anticoagulants and inhibitors - Treatment of spontaneous FVIII inhibitor - Acquired disorders of platelet function - Henoch–Schönlein purpura - Perioperative bleeding and massive blood loss - Massive blood loss - Heparin - Heparin induced thrombocytopenia/with thrombosis (HIT/T) - Oral anticoagulant therapy (warfarin, VKAs) - New oral anticoagulant drugs - Thrombosis - Risk assessment and thromboprophylaxis - Example of VTE risk assessment - Heritable thrombophilia - Acquired thrombophilia - Thrombotic thrombocytopenic purpura (TTP) - Haemolytic uraemic syndrome (HUS) - Heparin-induced thrombocytopenia (HIT)

Neutrophilia - Neutropenia - Lymphocytosis and lymphopenia - Eosinophilia - Basophilia and basopenia - Monocytosis and monocytopenia - Mononucleosis syndromes

Introduction - Using the blood transfusion laboratory - Transfusion of red blood cells - Platelet transfusion - Fresh frozen plasma - Intravenous immunoglobulin - Transfusion transmitted infections - Irradiated blood products - Strategies for reducing blood transfusion in surgery - Maximum surgical blood ordering schedule (MSBOS) - Patients refusing blood transfusion for religious reasons, i.e. Jehovah’s Witnesses

Myelodysplastic syndromes (MDS) - Classification of MDS - Clinical features of MDS - Prognostic factors in MDS - Clinical variants of MDS - Management of MDS - Response criteria - Myelodysplastic/myeloproliferative diseases (MDS/MPD)

The peripheral blood film in anaemias - Anaemia in renal disease - Anaemia in endocrine disease - Anaemia in joint disease - Anaemia in gastrointestinal disease - Anaemia in liver disease - Iron (Fe) deficiency anaemia - Vitamin B12 deficiency - Folate deficiency - Other causes of megaloblastic anaemia - Anaemia in other deficiency states - Haemolytic syndromes - Genetic control of haemoglobin production - Sickling disorders - HbS—sickle-modifying therapies - Sickle cell trait (HbAS) - Other sickling disorders - Other haemoglobinopathies - Unstable haemoglobins - Thalassaemias - α‎ thalassaemia - β‎ thalassaemia - Other thalassaemias - Hereditary persistence of fetal haemoglobin - Hb patterns in haemoglobin disorders - Non-immune haemolysis - Hereditary spherocytosis - Hereditary elliptocytosis - Glucose-6-phosphate dehydrogenase (G6PD) deficiency - Pyruvate kinase deficiency - Other red cell enzymopathies - Drug-induced haemolytic anaemia - Methaemoglobinaemia - Microangiopathic haemolytic anaemia - Acanthocytosis - Autoimmune haemolytic anaemia - Cold haemagglutinin disease - Leucoerythroblastic anaemia - Aplastic anaemia - Paroxysmal nocturnal haemoglobinuria - Pure red cell aplasia - Iron (Fe) overload - Transfusion haemosiderosis

Septic shock/neutropenic fever - Acute transfusion reactions - Delayed transfusion reaction - Post-transfusion purpura - Hypercalcaemia - Hyperviscosity - Disseminated intravascular coagulation - Overdosage of thrombolytic therapy - Heparin overdosage - Heparin-induced thrombocytopenia - Warfarin overdosage - Massive blood transfusion - Paraparesis/spinal collapse - Leucostasis - Thrombotic thrombocytopenic purpura - Sickle crisis

Myeloproliferative neoplasms (MPNs) - Pathogenesis of the MPNs - Polycythaemia vera (PV) - Natural history of PV - Management of PV - Secondary erythrocytosis - Relative erythrocytosis - Idiopathic erythrocytosis - Essential thrombocythaemia - Reactive thrombocytosis - Primary myelofibrosis - Chronic neutrophilic leukaemia - Eosinophilic syndromes and neoplasms - Mastocytosis (mast cell disease) - Systemic mastocytosis - MPN—unclassifiable

Paraproteinaemias - Monoclonal gammopathy of undetermined significance (MGUS) - Asymptomatic multiple myeloma (‘smouldering’ myeloma) - Multiple myeloma - Variant forms of myeloma - Cryoglobulinaemia - POEMS syndrome (osteosclerotic myeloma) - Plasmacytoma - Waldenström macroglobulinaemia - Heavy chain disease - AL (1° systemic) amyloidosis

Congenital immunodeficiency syndromes - Acquired immune deficiencies - HIV infection and AIDS - Therapy of HIV infection

Significance Bone marrow failure (BMF) is an inherited life-threatening condition characterized by defective hematopoiesis, developmental abnormalities, and predisposition to cancer. BMF caused by ERCC6L2 mutations is considered to be a genome instability syndrome, because DNA repair is compromised in patient cells. In this study, we report BMF cases with biallelic disease-causing variants and provide evidence from patients’ cells that transcription deficiency can explain the genome instability. Specifically, we demonstrate that ERCC6L2 participates in RNA polymerase II-mediated transcription via interaction with DNA-dependent protein kinase (DNA-PK) and resolves DNA–RNA hybrids (R loops). Collectively, our data point to a causal mechanism in BMF in which patients with ERCC6L2 mutations are defective in the repair of transcription-associated DNA damage., Biallelic variants in the ERCC excision repair 6 like 2 gene (ERCC6L2) are known to cause bone marrow failure (BMF) due to defects in DNA repair and mitochondrial function. Here, we report on eight cases of BMF from five families harboring biallelic variants in ERCC6L2, two of whom present with myelodysplasia. We confirm that ERCC6L2 patients’ lymphoblastoid cell lines (LCLs) are hypersensitive to DNA-damaging agents that specifically activate the transcription coupled nucleotide excision repair (TCNER) pathway. Interestingly, patients’ LCLs are also hypersensitive to transcription inhibitors that interfere with RNA polymerase II (RNA Pol II) and display an abnormal delay in transcription recovery. Using affinity-based mass spectrometry we found that ERCC6L2 interacts with DNA-dependent protein kinase (DNA-PK), a regulatory component of the RNA Pol II transcription complex. Chromatin immunoprecipitation PCR studies revealed ERCC6L2 occupancy on gene bodies along with RNA Pol II and DNA-PK. Patients’ LCLs fail to terminate transcript elongation accurately upon DNA damage and display a significant increase in nuclear DNA–RNA hybrids (R loops). Collectively, we conclude that ERCC6L2 is involved in regulating RNA Pol II-mediated transcription via its interaction with DNA-PK to resolve R loops and minimize transcription-associated genome instability. The inherited BMF syndrome caused by biallelic variants in ERCC6L2 can be considered as a primary transcription deficiency rather than a DNA repair defect.

Sally B. Killick (Writing Group Chair), Nick Bown, Jamie Cavenagh, Inderjeet Dokal, Theodora Foukaneli, Peter Hillmen, Robin Ireland, Austin Kulasekararaj, Ghulam Mufti, John A Snowden, Sujith Samarasinghe, Anna Wood (BCSH Task Force Member), Judith C.W. Marsh on behalf of the British Society for Standards in Haematology. The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust, Bournemouth, Northern Genetics Service, Newcastle upon Tyne, St Bartholomew’s Hospital, Barts Health NHS Trust, London, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Barts Health NHS Trust, London, Addenbrooks Hospital, University of Cambridge, Cambridge, Leeds Teaching Hospitals, Leeds, Kings College Hospital NHS Foundation Trust, London, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Great Ormond Street Hospital for Children NHS Foundation Trust, London, West Hertfordshire NHS Trust, Watford.