Classification of and risk factors for hematologic complications in a French national cohort of 102 patients with Shwachman-Diamond syndrome.

International audienceBACKGROUND: Patients with the Shwachman-Diamond syndrome often develop hematologic complications. No risk factors for these complications have so far been identified. The aim of this study was to classify the hematologic complications occurring in patients with Shwachman-Diamond syndrome and to investigate the risk factors for these complications. DESIGN AND METHODS: One hundred and two patients with Shwachman-Diamond syndrome, with a median follow-up of 11.6 years, were studied. Major hematologic complications were considered in the case of definitive severe cytopenia (i.e. anemia <7 g/dL or thrombocytopenia <20 × 10(9)/L), classified as malignant (myelodysplasia/leukemia) according to the 2008 World Health Organization classification or as non-malignant. RESULTS: Severe cytopenia was observed in 21 patients and classified as malignant severe cytopenia (n=9), non-malignant severe cytopenia (n=9) and malignant severe cytopenia preceded by non-malignant severe cytopenia (n=3). The 20-year cumulative risk of severe cytopenia was 24.3% (95% confidence interval: 15.3%-38.5%). Young age at first symptoms (<3 months) and low hematologic parameters both at diagnosis of the disease and during the follow-up were associated with severe hematologic complications (P<0.001). Fifteen novel SBDS mutations were identified. Genotype analysis showed no discernible prognostic value. CONCLUSIONS Patients with Shwachman-Diamond syndrome with very early symptoms or cytopenia at diagnosis (even mild anemia or thrombocytopenia) should be considered at a high risk of severe hematologic complications, malignant or non-malignant. Transient severe cytopenia or an indolent cytogenetic clone had no deleterious value

EFL1 mutations impair eIF6 release to cause Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is a recessive disorder typified by bone marrow failure and predisposition to hematological malignancies. SDS is predominantly caused by deficiency of the allosteric regulator Shwachman-Bodian-Diamond syndrome that cooperates with elongation factor-like GTPase 1 (EFL1) to catalyze release of the ribosome antiassociation factor eIF6 and activate translation. Here, we report biallelic mutations in EFL1 in 3 unrelated individuals with clinical features of SDS. Cellular defects in these individuals include impaired ribosomal subunit joining and attenuated global protein translation as a consequence of defective eIF6 eviction. In mice, Efl1 deficiency recapitulates key aspects of the SDS phenotype. By identifying biallelic EFL1 mutations in SDS, we define this leukemia predisposition disorder as a ribosomopathy that is caused by corruption of a fundamental, conserved mechanism, which licenses entry of the large ribosomal subunit into translation.Medical Research Council, Bloodwise, Wellcome Trust, Ted’s Gang, The Connor Wright Shwachman Diamond Projec

Granulopoïèse et leucémogenèse

Les neutropénies congénitales sont des maladies extrêmement rares, définies par une diminution permanente ou intermittente des neutrophiles circulants dans le sang. Les bases moléculaires de plusieurs de ces neutropénies ont récemment été déterminées, impliquant en particulier les gènes codant pour l’élastase neutrophile ELA2, le proto-oncogène GFI1, la protéine WASP et la protéine mitochondriale HAX1. Ces mutations, transmises selon un mode autosomique dominant (ELA2, GFI1), lié à l’X (WAS) ou autosomique récessif (HAX1) ont pour conséquence des modifications de la stabilité du contenu des granules - en particulier de l’élastase neutrophile -, des anomalies du cytosquelette et possiblement un excès d’apoptose. Les mutations ELA2 sont associées soit à une neutropénie profonde permanente, soit à une neutropénie intermittente, pseudo-sinusoïdale, suggérant que ces pathologies sont peut-être assez proches et que la variation temporelle des neutrophiles peut être modélisée par une fonction non linéaire. Les neutropénies congénitales, en particulier liées à ELA2, sont caractérisées par un risque leucémogène important (environ 15 % à 20 ans). Ce risque apparaît lié non pas à un effet oncogène des mutations, mais avant tout à la profondeur de la neutropénie, et par voie de conséquence à l’intensité du traitement par G-CSF qui est proposé à ces patients

Congenital neutropenia: diagnosis, molecular bases and patient management

<p>Abstract</p> <p>The term congenital neutropenia encompasses a family of neutropenic disorders, both permanent and intermittent, severe (<0.5 G/l) or mild (between 0.5-1.5 G/l), which may also affect other organ systems such as the pancreas, central nervous system, heart, muscle and skin. Neutropenia can lead to life-threatening pyogenic infections, acute gingivostomatitis and chronic parodontal disease, and each successive infection may leave permanent sequelae. The risk of infection is roughly inversely proportional to the circulating polymorphonuclear neutrophil count and is particularly high at counts below 0.2 G/l.</p> <p>When neutropenia is detected, an attempt should be made to establish the etiology, distinguishing between acquired forms (the most frequent, including post viral neutropenia and auto immune neutropenia) and congenital forms that may either be isolated or part of a complex genetic disease.</p> <p>Except for ethnic neutropenia, which is a frequent but mild congenital form, probably with polygenic inheritance, all other forms of congenital neutropenia are extremely rare and have monogenic inheritance, which may be X-linked or autosomal, recessive or dominant.</p> <p>About half the forms of congenital neutropenia with no extra-hematopoetic manifestations and normal adaptive immunity are due to neutrophil elastase (<it>ELANE</it>) mutations. Some patients have severe permanent neutropenia and frequent infections early in life, while others have mild intermittent neutropenia.</p> <p>Congenital neutropenia may also be associated with a wide range of organ dysfunctions, as for example in Shwachman-Diamond syndrome (associated with pancreatic insufficiency) and glycogen storage disease type Ib (associated with a glycogen storage syndrome). So far, the molecular bases of 12 neutropenic disorders have been identified.</p> <p>Treatment of severe chronic neutropenia should focus on prevention of infections. It includes antimicrobial prophylaxis, generally with trimethoprim-sulfamethoxazole, and also granulocyte-colony-stimulating factor (G-CSF). G-CSF has considerably improved these patients' outlook. It is usually well tolerated, but potential adverse effects include thrombocytopenia, glomerulonephritis, vasculitis and osteoporosis. Long-term treatment with G-CSF, especially at high doses, augments the spontaneous risk of leukemia in patients with congenital neutropenia.</p

Profil neuropsychologique et capacitésmétapragmatiques dans le syndrome deSchachman-Diamond

International audienceThe main objective of this pilot study is to put forth innovative hypotheses on the neuropsychological profile of French children and adolescents with Shwachman-Diamond syndrome (SDS), a rare genetic disease. It also assesses the pragmatic abilities, by means of discursive comprehension tests of three non-literal forms of indirect requests specifically designed for this population. The originality of this work lies in the analysis of behavioural profiles and in the study of higher cognitive functions of 7 SDS children. In addition to their intellectual disability, over half of SSD children present socio-cognitive difficulties and all exhibit behavioural (notably social adaptation) and executive complaints. The results highlight specific performance profiles within the various tests assessing social cognition. The hypothesis of a specific impairment of certain aspects of the theory of mind is thus raised.L’objectif principal de cette étude pilote est d’avancer des hypothèses novatrices quant au profil neuropsychologique des enfants et adolescents français porteurs du Syndrome de Shwachman-Diamond (SSD), maladie génétique rare. Il s’agit également d’évaluer les capacités métapragmatiques à partir d'épreuves de compréhension de demandes en situation de dialogue. Ces demandes sont présentées sous trois formes non littérales spécifiquement aménagées pour cette population. L’originalité de ce travail réside ainsi dans l’analyse des profils comportementaux et dans l’étude des fonctions cognitives supérieures de 7 enfants SSD. Au-delà de l’affaiblissement intellectuel observé pour notre échantillon, plus de la moitié des enfants SSD présentent des difficultés de cognition sociale et tous manifestent des problèmes comportementaux (notamment d’adaptation sociale) et exécutifs. Les résultats obtenus mettent en évidence des profils de performances originaux au sein des différentes épreuves évaluant la cognition sociale. L’hypothèse d’une atteinte spécifique de certains aspects de la théorie de l’esprit est ainsi soulevée

Identification of biallelic germline variants of SRP68 in a sporadic case with severe congenital neutropenia

International audienc

Cardiomyopathies and congenital heart diseases in Shwachman-Diamond syndrome: a national survey

International audienceno abstrac

Biallelic CXCR2 loss-of-function mutations define a distinct congenital neutropenia entity

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Description and outcome of a cohort of 8 patients with WHIM syndrome from the French Severe Chronic Neutropenia Registry.

International audienceBACKGROUND: WHIM syndrome (WS), a rare congenital neutropenia due to mutations of the CXCR4 chemokine receptor, is associated with Human Papillomavirus (HPV)-induced Warts, Hypogammaglobulinemia, bacterial Infections and Myelokathexis. The long term follow up of eight patients highlights the clinical heterogeneity of this disease as well as the main therapeutic approaches and remaining challenges in the light of the recent development of new CXCR4 inhibitors. OBJECTIVE: This study aims to describe the natural history of WS based on a French cohort of 8 patients. METHODS: We have reviewed the clinical, biological and immunological features of patients with WS enrolled into the French Severe Chronic Neutropenia Registry. RESULTS: We identified four pedigrees with WS comprised of eight patients and one foetus. Estimated incidence for WS was of 0.23 per million births. Median age at the last visit was 29 years. Three pedigrees encompassing seven patients and the fetus displayed autosomal dominant heterozygous mutations of the CXCR4 gene, while one patient presented a wild-type CXCR4 gene. Two subjects exhibited congenital conotruncal heart malformations. In addition to neutropenia and myelokathexis, all patients presented deep monocytopenia and lymphopenia. Seven patients presented repeated bacterial Ears Nose Throat as well as severe bacterial infections that were curable with antibiotics. Four patients with late onset prophylaxis developed chronic obstructive pulmonary disease (COPD). Two patients reported atypical mycobacteria infections which in one case may have been responsible for one patient's death due to liver failure at the age of 40.6 years. HPV-related disease manifested in five subjects and progressed as invasive vulvar carcinoma with a fatal course in one patient at the age of 39.5 years. In addition, two patients developed T cell lymphoma skin cancer and basal cell carcinoma at the age of 38 and 65 years. CONCLUSIONS: Continuous prophylactic anti-infective measures, when started in early childhood, seem to effectively prevent further bacterial infections and the consequent development of COPD. Long-term follow up is needed to evaluate the effect of early anti-HPV targeted prophylaxis on the development of skin and genital warts