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Leber hereditary optic neuropathy (LHON) is a rare mitochondrial disease, responsible for blindness by bilateral involvement of central vision. It usually affects young men but can occur at any age and in women. Its diagnosis is suspected on the family history and the initial clinical picture, and the definitive diagnosis of LHON is obtained by genetic testing and the molecular identification of the mitochondrial genetic point mutation. The initial workup should include an assessment of visual structure and function. Its visual prognosis is severe, but depends on the causative mutation. Support should include genetic counseling, a therapeutic proposal and a support for visual impairment.

An ingenious system for generating thousands of point mutations in yeast genes and measuring their effect on fitness shows convincingly that, for the chosen subset of representative non-essential genes, silent mutations have as much effect on fitness as missense mutations. In other words, silent mutations are not neutral, at least under these conditions. This result has important implications for evolutionary biology.

Hutchinson-Gilford Progeria (acute premature aging) is caused by a de novo point mutation in the lamin A gene. Recently, this mutation has been accurately corrected by base editing in patient cell lines and in a mouse model, resulting in nearly complete reversal to a normal phenotype. This success opens the perspective for clinical applications in Progeria and other diseases.

In the context of chronic myeloid leukemia (CML) resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL1 tyrosine kinase domain (TKD) mutations still remain the sole biological marker that directly condition therapeutic decision. These recommendations aim at updating the use of BCR-ABL1 mutation testing with respect to new available therapeutic options and at repositioning different testing methods at the era of next generation sequencing (NGS). They have been written by a panel of experts from the French Study Group on CML (Fi-LMC), after a critical review of relevant publications. TKD mutation testing is recommended in case of treatment failure but not in case of optimal response. For patients in warning situation, mutation testing must be discussed depending on the type of TKI used, lasting of the treatment, kinetic evolution of BCR-ABL1 transcripts along time and necessity for switching treatment. The kind and the frequency of TKD mutations occasioning resistance mainly depend on the TKI in use and disease phase. Because of its better sensitivity, NGS methods are recommended for mutation testing rather than Sanger's. Facing a given TKD mutation, therapeutic decision should be taken based on in vitro sensitivity and clinical efficacy data. Identification by sequencing of a TKD mutation known to induce resistance must lead to a therapeutic change. The clinical value of testing methods more sensitive than NGS remains to be assessed.

Medullary thyroid cancer (MTC) is a rare thyroid tumor whose prevalence is 3–5% among all thyroid tumors. The pathogenesis of MTC is mainly related to germline or somatic RET activating point mutations that are causative of hereditary and sporadic cases, respectively. Hereditary MTC can occur as multiple endocrine neoplasia type 2A (MEN 2A), type 2B (MEN 2B) and familial MTC (FMTC) that differ for the association with other endocrine neoplasia. Germline RET point mutations are prevalently localized in exons 5, 8, 10–11, 13–16 and a significant genotype-phenotype correlation has been observed. RET genetic screening is mandatory in all patients with a diagnosis of MTC regardless from their apparent sporadic origin. The identification of RET germline mutation in an apparently sporadic case is of great clinical utility because it allows the identification of those subjects who will develop the tumor. RET positive relatives must undergo clinical and biochemical tests to verify if the MTC is already present and, according to the type of RET mutation, they have to be screened for the presence of pheochromocytoma and/or hyperparathyroidism. If a MTC is already present patients must be surgically treated. If MTC is not yet present subjects will be followed up with basal and stimulated calcitonin serum measurement, which is the serum marker of MTC. Indeed, RET negative subjects can be reassured that they do not run any risk to develop the disease as well as their children. In conclusions RET genetic screening allows the identification of the hereditary/sporadic nature of MTC and of a relevant percentage of hidden familial MTC. Furthermore, it favors the early diagnosis of MTC in RET positive subjects. RET positive patients and no clinical evidence of MTC can be followed and surgical treatment can be delayed. Finally RET negative relatives do not need to be further monitored.

We report the case of a 22-year-old patient with acute abdominopelvic pain. The diagnosis of hypercalcemic small cell carcinoma (SCCOHT)/ovarian rhabdoid tumor has been made. Small cell carcinoma of hypercalcemic type is a rare and aggressive tumor that occurs in young women. The diagnosis of this tumor and the management must be rapid in view of its aggressiveness. Through this observation, we specify the epidemiological, diagnostic, molecular aspects and discussions about its name.

We report the case of an 11-year-old patient diagnosed with a solid variant of papillary thyroid carcinoma. Papillary thyroid carcinoma (PTC) is the most common thyroid cancer, representing 80-90% of all newly diagnosed thyroid cancers. Among the many variants described, solid/trabecular variant of papillary thyroid carcinoma is a rare entity and account for 3% of thyroid cancers. It is more common in children and young adults, and it is seen in higher proportion in post radiation papillary thyroid carcinoma cases. Histologically, solid variant papillary carcinoma is characterized by a predominantly solid, trabecular or insular growth pattern, and the presence of cytological features typical of PTC. Its main differential diagnosis is poorly differentiated thyroid carcinoma. It has a less favorable prognosis than the classical papillary type, with a higher risk of distant metastasis, extrathyroidal extension and lympho-vascular invasion. It is associated with a slightly lower long-term survival in adult cases, but not in children. The management of solid variant PTC includes surgery, associated or not with postoperative radioiodine ablation, according to the aggressiveness criteria. Our patient had a DICER1 somatic mutation. Carriers of germline DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 syndrome, with a higher risk of numerous tumors and infrequently differentiated thyroid carcinomas.

Ichthyosis prematurity syndrome is a rare syndromic form of ichthyosis caused by mutations in FATP4, which plays a central role in the transport and activation of fatty acids in the epidermis and in epidermal barrier function. Despite stereotypical clinical presentation in the neonatal period, the diagnosis is not well known by clinicians. Herein we report two new cases.Case no. 1: a boy born prematurely (33weeks of gestation) to non-consanguineous French parents presented at birth with respiratory distress necessitating admission to intensive care. His skin was covered by a thick caseous vernix, especially on the scalp, eyebrows and 4 limbs. At the age of 4years, the boy's skin appeared normal. Case no. 2: a boy born prematurely to consanguineous Moroccan parents (34weeks of gestation) presented at birth with respiratory distress requiring admission to intensive care. At clinical examination, he had a whitish thick skin giving an impression of vernix caseosa, with involvement of the scalp, forehead, 4 limbs and abdomen. At the age of 2 years, his skin was normal.The clinical presentation of this syndrome is typical. It is important to make the diagnosis to enable genetic counseling and planning of adequate neonatal care in the event of future pregnancies.

Griscelli syndrome (GS) is a rare autosomal-recessive genetic disease characterized by hypopigmentation of skin and hair. We report a case of GS type 3 with late diagnosis.A 31-year-old female patient had presented depigmentation of the hair and eyebrows as well as diffuse skin hypopigmentation during childhood. Microscopic analysis of a hair shaft revealed irregularly distributed clumps of melanin. DNA sequencing showed a homozygous C103T (R35W) transition in exon 1 of MLPH, confirming Griscelli syndrome type 3.Three clinical phenotypes of GS have been described based on the underlying genetic defect. GS type 1 and 2 are associated respectively with a central nervous system dysfunction and an immune defect. GS type 3 is an isolated cutaneous form. Diagnosis is confirmed on microscopic examination of hair shafts. 15 cases of GS type 3 have been reported: 9 in males and 6 in females. Mean age at diagnosis is around 12 years. Nine of the reported patients were of Arab origin, four of Turkish origin, and one of Indian origin. R35W mutation was described in 9 cases and E98X and R35Q mutations were each found in one case.GS should be suspected in patients presenting gray silvery hair, particularly when these patients are of Arab or Turkish origin.

Developmental genetics of congenital heart diseases has evolved from analysis of serial slices in embryos towards molecular genetics of cardiac morphogenesis with a dynamic view of cardiac development. Genetics of congenital heart diseases has also changed from formal genetic analysis of familial recurrences or population-based analysis to screening for mutations in candidates genes identified in animal models. Close cooperation between molecular embryologists, pathologists involved in heart development and pediatric cardiologists is crucial for further increase of knowledge in the field of cardiac morphogenesis and genetics of cardiac defects. The genetic model for congenital heart disease has to be revised to favor a polygenic origin rather than a monogenic one. The main mechanism is altered genic dosage that can account for heart diseases in chromosomal anomalies as well as in point mutations in syndromic and isolated congenital heart diseases. The use of big data grouping information from cardiac development, interactions between genes and proteins, epigenetic factors such as chromatin remodeling or DNA methylation is the current source for improving our knowledge in the field and to give clues for future therapies.

International audience; Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by mutations in the DMD gene that encodes the cytoskeletal protein, dystrophin. Dystrophinopathies are inherited in an X-linked recessive manner. Due to the tremendous size of the gene (2.2 megabases), the DMD locus has a high spontaneous mutation rate, and one third of sporadic cases of DMD are due to a de novo mutation. There are seven tissue-specific promoters in the gene. The skeletal muscular transcript contains 79 exons and encode the full-length protein (427-kDa) located at the inner face of the sarcolemma of muscle fibers. DMD gene mutations are highly heterogeneous. Large rearrangements (deletions or duplications of one or more exons) are most frequently involved while point mutations account for 20 %-30 % of cases. A survey of current strategies of molecular diagnosis is presented here. In particular, the role of muscle biopsy (for dystrophin and RNA analyses) in the diagnosis of dystrophinopathies is discussed. In more than 90 % of cases, the clinical severity is correlated with the impact of the mutations on the reading frame and the expression of the dystrophin (absence or residual amount of mutated protein). Various mechanisms contribute to the exceptions. Besides the clinical interest for the patient, the identification of the mutation allows accurate genetic counseling in the familles, and is a necessary prerequisite for the inclusion of the patient in the genotype-based clinical trials.

Glutamate is the major excitatory neurotransmitter in the Central Nervous System (CNS) and is accumulated into synaptic vesicles by proton-dependent transporters named VGLUT1-3. VGLUT1 and VGLUT2-positive neurons are respectively found in cortical and subcortical glutamatergic neurons. In contrast, VGLUT3 is localized in a small population of neurons using other neurotransmitter than glutamate i.e.: cholinergic interneurons in the striatum, subpopulation of GABAergic interneurons in the hippocampus and cortex and serotoninergic neurons. Furthermore, VGLUT3 is also expressed by sensory inner hear cells (IHCs).In the cochlea, VGLUT3 accumulates glutamate into synaptic vesicles of the IHCs. A mutation of the gene that encodes VGLUT3 is responsible for a progressive, high-frequency deafness. It is the first mutation of a VGLUT that was demonstrated to be responsible for a human pathology.We investigated the effects of the p.A211V mutation on VGLUT3 in the CNS of a mouse line expressing this mutation. We observed that this mutation had complex effects on VGLUT3. The p.A211V mutation causes a 80% decrease of VGLUT3 in nerve endings. 20% residual expression of VGLUT3 is sufficient to fulfill most part of its functions. Contrary to prevailing views, VGLUT3 global activity is not linearly correlated to VGLUT3 quantity. Futhermore, VGLUT3 reduction seems to be associated with a diminution of VGLUT3-positive vesicles accompanied by an homogenous reduction of VGLUT3 copy number per vesicle.Overall, my thesis allowed to acquire a better understanding of the regulation of VGLUT3. This work will deepen our understanding of the involvement of VGLUTs in various pathologies.; Le glutamate est accumulé dans des vésicules synaptiques par des transporteurs vésiculaires du glutamate appelés VGLUT1-3. VGLUT1 et VGLUT2 sont utilisés par les neurones glutamatergiques «classiques» corticaux et sous-corticaux. VGLUT3 est présent dans des sous-populations de neurones utilisant d’autres neurotransmetteurs que le glutamate. Dans la cochlée, VGLUT3 permet la transmission glutamatergique entre les cellules ciliées internes et les neurones du nerf auditif. Le travail mené par l’équipe du Pr Puel a permis de découvrir l’implication de VGLUT3 dans une pathologie héréditaire de l’audition chez l’Homme. Une mutation p.A211V du gène codant VGLUT3 humain est responsable d’une surdité progressive à transmission autosomique. Il s’agit de la première mutation d’un VGLUT associé à une pathologie humaine. Mon travail de thèse a consisté à caractériser l’impact de cette mutation sur le SNC d’une lignée de souris exprimant cette mutation. Nous avons observé que cette mutation avait des effets complexes sur VGLUT3. La mutation p.A211V entraine une baisse marquée de l’expression de VGLUT3 dans les terminaisons nerveuses qui semble liée à une dégradation accélérée de VGLUT3. 20% d’expression résiduelle de VGLUT3 suffisent à assurer la majeure partie des fonctions du transporteur. L’activité de VGLUT3 ne semble donc pas être linéairement corrélée à son expression. De plus, la réduction de VGLUT3 au niveau des synapses semble s’accompagner d’une réduction du nombre de vésicules VGLUT3-positives et d’une réduction du nombre de copies de VGLUT3 par vésicule. Dans l’ensemble, mon travail de thèse a permis d’acquérir une meilleure connaissance de la régulation de VGLUT3.

Succinylcholine is a neuromuscular block whose duration of action depends on rapid hydrolysis by butyrylcholinesterase (BChE). In patients with common BChE activities, succinylcholine duration of action is short (10min). BChE deficiency induces a slower hydrolysis of the drug and consequently prolonged neuromuscular block, leading to apnea. We report a case of prolonged neuromuscular block after administration of succinylcholine in a 14-year-old boy. Biological investigations revealed a marked BChE deficiency (1099U/L) related to the presence of three point mutations in the BCHE gene in a compound heterozygous state: p.Asp70Gly (rs1799807), p.Ala539Tyr (rs1803274), and p.Phe118Valfs*12 (rs398124632). The diagnosis of genetic BChE deficiency (OMIM 177400) was retained. This case is intended to present the pathophysiology of genetic BChE deficiency, its management, and the diagnostic strategy to be implemented.

International audience

The understanding of the biology of pancreatic carcinoma has greatly benefited from studies of genetic/epigenetic alterations and molecular expression in experimental models as well as precancerous and cancerous tissues by mean of molecular amplification and large-scale transcriptoma analysis. P16, TP53, DPC4/Smad4 tumor suppressor pathways are genetically inactivated in the majority of pancreatic carcinomas, whereas oncogenic k-ras is activated. The activating point mutation of the KRAS oncogene on codon 12 is the major event and occurs early in pancreatic carcinogenesis. At a late stage of tumor development, an increase of telomerase activity, an over expression of growth factors and/or their receptors (EGF, Nerve Growth Factor, gastrin), of pro-angiogenic factors (VEGF, FGF, PDGF), of invasiveness factors (metalloproteinases, tissue plasminogen activators) occurs. The microenvironment plays also a key role in the invasive and metastatic process of pancreatic carcinoma with a strong relationship between cancerous cells and pancreatic stellate cells as well as extracellular matrix. This microenvironment strongly participates to the tumor fibrosis, hypoxia and hypovascularization inducing an inaccessibility of drugs. Nowadays, the targeting of microenvironment takes a special place in the new therapeutic strategies of pancreatic cancer in combination with chemotherapy.

Negative BCR ABL myeloproliferative neoplasm (MPN) such as polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (MFP) are clonal hematological malignancies and may lead to a high risk of venous, arterial or microcirculatory thrombosis. Atypical sites of thrombosis can sometimes reveal the neoplasm disorder. Their diagnoses are a major issue because of the propensity to develop acute myeloid leukemia and/or myelofibrosis. The acquired JAK2V617F variant (Janus kinase 2; 9p24) is a prevalent MPN and also a sensitive marker for PV diagnosis (95% positive mutation), but not specific since found in approximately 50% of patients with ET and MFP.We present a diagnostic and a therapeutic approach based on one patient with microcirculatory ischemic manifestations in the toes, and who had strictly normal cell blood counts and was positive for JAK2V617F mutation: thrombotic risk factor evaluation; bone marrow biopsy; red cell adhesion assays. These experimental assays are promising for the development of new therapeutics in MPN; they assess red cell adherence to the vascular endothelium after the phosphorylation of Lu/BCAM subsequent to a positive JAK2V617F mutation.Compared with controls, our patient exhibited increased Lu/BCAM receptor phosphorylation and red blood cell adhesion.This development may lead to improved care for patients with thrombotic manifestations, normal blood cell counts, and a positive JAK2V617F mutation: multidisciplinary management, including regular hematological monitoring, could lead to the introduction of a cytoreductive treatment.

International audience; Melanomas have a high rate of brain metastases. Both the functional prognosis and the overall survival are poor in these patients. Until now, surgery and radiotherapy represented the two main modalities of treatment. Nevertheless, due to the improvement in the management of the extracerebral melanoma, the systemic treatment may be an option in patients with brain metastases. Immunotherapy with anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) - ipilimumab - or BRAF (serine/threonine-protein kinase B-raf) inhibitors - vemurafenib, dabrafenib - has shown efficacy in the management of brain metastases in a- or pauci-symptomatic patients. Studies are ongoing with anti-PD1 (programmed cell death 1) and combinations of targeted therapies associating anti-RAF (raf proto-oncogene, serine/threonine kinase) and anti-MEK (mitogen-activated protein kinase kinase).

The heterogeneity of tumours is now beginning to be documented precisely by single-cell new-generation sequencing. Recently published results on breast tumours show that each of the cells analysed displays a unique pattern of point mutations. This extensive genetic diversity is present before any treatment, and is likely to cause resistance to initially successful targeted therapies.

Somatic mutations in the calreticulin gene (CALR) were recently described in essential thrombocythemia (ET) and primary myelofibrosis with non-mutated JAK2 or MPL. The aim of this single-center study was to compare the clinical and biological features of ET patients according to their mutational status.We included 40 patients with ET followed in hematology consultation. The JAK2 V617F mutation was assessed by quantitative PCR. For the detection of CALR mutations, we performed a PCR amplification of CALR exon 9 followed by direct sequencing.Among 40 study patients, 23 (57.5%) harbored V617F JAK2, 12 of the 17 patients without JAK2 mutation harbored CALR, no patient expressed MPL mutation and 5 were negative for all three mutations. Five types of mutations were identified with predominance of 52bp deletion and 5bp insertion (7/12 and 2/12 respectively). The incidence of thrombotic events at diagnosis was significantly higher in JAK2 mutated patients (P0.05). Biologically, patients with CALR mutation had significantly higher platelet count (P0.01) and significantly lower hemoglobin level (P0.05) than those with V617F JAK2 mutation.JAK2 and CALR mutation screening in ET has a diagnostic value. Each mutation displays a distinct phenotype with uncertain impact on long-term outcome.

Soft tissue sarcomas (STS) are a set of very heterogeneous tumors with numerous histological categories. The development of the molecular biology allowed identifying recurring molecular anomalies in certain subgroups of sarcomas, being able to represent diagnostic, prognosis and therapeutic tools. The molecular classification of STS includes until today 5 main groups of abnormalities: sarcomas with "simple genomic profile" showing reciprocal (1) chromosomal translocations, (2) activating mutation, (3) inhibitive mutation or (4) simple amplification; (5) sarcomas with "complex genomic profile" can include several tens of molecular abnormalities. The development of new-targeted therapies is based on the identification of a target, specific of a tumors subgroup and involved in carcinogenesis mechanisms and/or tumoral growth. Then, the aim of clinical research is to establish the proof of the concept through clinical trials, demonstrating the benefit brought to the patient and ending in the marketing of the drug. This proof of the concept was clearly established for imatinib, sunitinib and regorafenib in gastrointestinal stromal tumors, for imatinib in dermatofibrosarcoma protuberans and pigmented vilo-nodular synovitis, for denosumab in giant cell tumors of the bone, ending in the authorization to use these new therapies in these indications. It is in progress and promising for anti-IGF-1R in Ewing sarcomas, for crizotinib in myofibroblastic inflammatory tumors, for mTOR inhibitor in PEComas... The role of molecular abnormalities identified in the mechanisms of tumoral progress for sarcomas and their potential therapeutic impact will be detailed.

Pulmonary Langerhans cell histiocytosis is a rare diffuse cystic interstitial pneumonia of unknown etiology that occurs selectively in young smokers of both genders. The multicenter studies conducted by the reference center have better defined the short and medium terms natural history of the disease and the clinical management of patients. A substantial proportion of patients experience a dramatic decline in their lung function soon after diagnosis. Importantly, smoking cessation is associated with a decreased risk of subsequent deterioration. Cladribine, a purine analogue, chemotherapy may dramatically improve lung function in patients with progressive pulmonary Langerhans cell histiocytosis, but this treatment should be used only in the setting of clinical research. Specific pulmonary hypertension therapies (anti-endothelin receptors, inhibitors of phosphodiesterases) may be used with caution in specialized centres for patients with severe pulmonary hypertension, and seem to be well tolerated. The recent identification of the V600E mutation of the BRAF oncogene in approximately half of the Langerhans cell histiocytosis lesions, including pulmonary granulomas, represents an important step forward in the understanding of the pathogenesis of Langerhans cell histiocytosis. Potentially it opens the way to targeted therapies.

Cutaneous melanoma is a malignant tumor with a high metastatic potential. If an early treatment is associated with a favorable outcome, the prognosis of metastatic melanoma remains poor. Advances in molecular characterization of cancers, notably the discovery of BRAF gene mutations in metastatic melanoma, allowed to the recent development of targeted therapies against mutated BRAF protein. Despite high tumor response rates observed in clinical trials, these new drugs are associated with frequent secondary tumor resistance occurrence and paradoxical carcinogenic side effects. The cellular and molecular mechanisms of these carcinogenic side effects and secondary resistance are not yet fully elucidated and are actually intensely studied. This review of the literature focus on the mechanisms of these carcinogenic side effects and on the tumor resistance associated with anti-BRAF targeted therapies.

A patient presenting with paramyotonia congenita (Eulenburg's paramyotonia) was seen at the preanaesthetic visit during pregnancy. The underlying disease was known for years. Analysis of the literature and advice taken from specialists emphasized the safe use of regional anaesthesia and analgesia which was indeed used for labour and delivery without any complication. By contrast, the limited information available on the use of general anaesthesia suggests the risks associated with the use of succinylcholine and possibly with halogenated agents. Additional and useful factors that may limit the occurrence of myotonic crises such as maintenance of normal temperature and plasma potassium concentration, should be undertaken simultaneously.

International audience; Cancer is a known risk factor for the development of venous thromboembolism (VTE) and in particular, adenocarcinoma of the lung is known to be associated with a higher risk of thromboembolic event. EGFR activating mutations are more frequently found in this histological subtype than in other lung cancers. We report three cases of VTE in patients with adenocarcinoma of the lung and EGFR activating mutation. Our reported case series is atypical because the VTE event occurred early in the adenocarcinoma history: either leading to the diagnosis of cancer, or appearing very early in the management of the neoplasm.

Two major pathways are described in bladder carcinogenesis: one for invasive or high grade tumors characterized by alteration of the p53 tumor suppressor gene and the other for non-invasive tumors or low grade involving mutations FGFR3. The objective of our study was to validate the research in the urine of mutations in these two genes in patients with a bladder tumor.In our preliminary study, we investigated 36 patients the FGFR3 and p53 mutations in tumors and urine collected during endoscopic resection. The p53 mutations were sought in FASAY, which allows a functional analysis of the protein P53. The FGFR3 mutations were sought in SNaPshot that searches the eight most frequent mutation points of this gene.For 24 patients (66% of cases), we found at least one of the two mutations in the tumor. This mutation was present in the urine in 15 patients (sensitivity=62.5%). In only one patient, we found a mutation in the urinary sediment that did not exist in the tumor (specificity=91.7%).The search for mutations of p53 and FGFR3 in the urine was a simple and non-invasive assay, which seems superior to urinary cytology for the detection of bladder tumors, raising hopes of an interest in this bio-assay for surveillance of bladder tumors and screening risk populations.

Nontraumatic subarachnoid hemorrhage is a relatively rare disease, typically secondary to a ruptured aneurysm. We report the case of a 23-year-old patient who developed a subarachnoid hemorrhage caused by extensive cerebral venous thrombosis due to a factor V Leiden mutation. Cerebral venous thrombosis is an uncommon etiology of subarachnoid hemorrhage. This raises diagnostic difficulties and a therapeutic dilemma regarding the use of anticoagulants.

ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 repeats) is the specific von Willebrand factor (VWF)-cleaving protease. ADAMTS13 was partially purified from human plasma in 1996 and its gene was cloned in 2001. In case of vascular injury, multimeric VWF is the mediator of both platelet adhesion to the sub-endothelium and platelet aggregation within the microvessels at high shear rates of blood flow. ADAMTS13 regulates VWF adhesive capacity by reducing the size of VWF multimers. A severe functional deficiency of ADAMTS13 (activity lower than 10%) is associated with most cases of thrombotic thrombocytopenic purpura (TTP), a thrombotic microangiopathy characterized by the spontaneous formation, within the microcirculation, of VWF-rich platelet thrombi responsible for a mechanical hemolytic anemia, a consumption thrombocytopenia and a multivisceral ishemia. TTP is a rare disease (4 cases/10(6)/year) with a life-threatening prognosis in the absence of an appropriate treatment in emergency (plasmatherapy). In 90% of cases, TTP is acquired and related to the development of auto-antibodies to ADAMTS13. In the other cases, TTP is inherited via bi-allelic autosomic recessive mutations of ADAMTS13 gene (Upshaw-Schulman syndrome). A better characterization of ADAMTS13 structure/function combined to clinical trials led in TTP patients is crucial to evaluate the relevance of either a -plasma-purified or a -recombinant ADAMTS13 as a therapeutic agent.

Distinct clinicopathologic acute lymphoblastic leukemia (ALL) entities have been identified, resulting in the adoption of risk-oriented treatment approaches. In Philadelphia chromosome-positive (Ph(+)) ALL, the optimal treatment requires the addition of BCR-ABL tyrosine kinase inhibitors, as imatinib. However, the outcome remains poor in absence of allogeneic stem cell transplantation, and novel agents are desperately required. Resistance attributable to kinase domain mutations can lead to relapse despite the development of second-generation compounds, including dasatinib and nilotinib. Despite these therapeutic options, the cross-resistant BCR-ABL (T315I) mutation remains a major clinical challenge. The first evaluations of AP24534 present this drug as a potent multi-targeted kinase inhibitor active against T315I and all other BCR-ABL mutants. AP24534 could be the next treatment of choice in hematological malignancies with Philadelphia-positive chromosome, particularly Ph(+) ALL known for its frequent occurrence of T315I mutation.

The HNPCC syndrome (hereditary non polyposis colon cancer) or Lynch syndrome stands for an autosomic dominant condition leading to the most prevalent hereditary colo-rectal cancers (CCR). MMR (mismatch repair)'s genes are involved in carcinogenesis as they play a role in ADNA mismatch repair. Microsatellite instability (MSI+ phenotype) induced by germline mutations is characteristic of such tumors and is necessary to assert the diagnosis. The HNPCC syndrome is associated with a significant increased risk of CCR altogether with endometrium, upper urinary tract and small bowel carcinomas as well as ovarian, biliary system and gastric cancers although of lesser extent. It is of importance to diagnose HNPCC syndrome prior to the treatment starts because it may influence patient's (as well as her/his relatives) disease management (type of surgery, surveillance and screening exams). New French recommendations, developed in 2009, about prophylactic colo-rectal and gynecologic surgeries and monitoring update latest ones published on 2004.

International audience; The purpose of the survey was the routine assessment of the MTBDRplus(®) kit performance in the determination and characterization of Mycobacterium tuberculosis resistance to rifampicin. The survey was carried out on a collection of 144 strains (126 of which were resistant to rifampicin) isolated on patients from 15 countries. Sensitivity to antituberculosis drugs was determined by a liquid culture system and the reference method was the amplification and sequencing of a target region of the rpoB gene whose mutations are responsible for rifampicin resistance (codons 507 to 533). The assessed kit was based on a reverse hybridization technique using eight overlapping probes covering the target region and four probes representing the most-frequently observed mutations. The assay performance was found excellent, specificity: 100%, sensitivity: 99.2%; 17 mutations affecting 10 codons were reported, two of which were newly identified.

BRAF mutations, present in 5 to 10% of colorectal cancers, have a proved oncogenic effect which is linked to their implication in the RAS/MAPK intracellular signalling pathway and they occurred at early stage of colorectal carcinogenesis. Many studies have therefore assessed their clinical significance as diagnostic and prognostic marker in colorectal cancers. More recently, their location downstream to EGFR and KRAS in the RAS/MAPK pathway have led to their evaluation as predictive marker of resistance to anti-EGFR monoclonal antibodies. This article aims to review the role of BRAF mutations in the diagnostic strategy of Lynch syndrome, their prognostic value in colorectal cancers and their potential value as predictive marker of resistance to anti-EGFR antibodies.

International audience; AIM: To screen hepatitis B virus (HBV) genotypes and associated basal core promoter (BCP; T1762A/A1764) and precore (PC; A1896) mutations among the 100 HBV surface antigen (HBsAg) positive voluntary blood donors in France.METHODS: HBV genotypes were determined by using direct sequence analysis. Three methods were used to detect G1896A mutation: non-commercial real-time PCR (PCRTR°, line probe assay (InnoLiPA HBV PreCore, INNOGENETICS(®)) and direct sequencing of precore gene. HBV viral load was quantified with two commercial real-time PCR (COBAS(®) AmpliPrep/COBAS(®) TaqMan(®) HBV Test/Roche and Real Time HBV/M2000/Abbott).RESULTS: The mean age of donors was 30 (18-64). Patients were from Africa (42%), Europa (50%), and Asia (8%). HBV/D was the most predominant (37%) genotype followed by HBV/A (31%) and HBV/E (22%). PC and BCP mutants were found in 57% with Inno-LIPA HBV test and 59% with both PCRTR and sequencing methods. A significant difference in the viral load of blood donors with wild and PC mutants was observed with the Taqman Cobas real time PCR (3,19 Log(10) UI/ml versus 4,93 Log(10) UI/ml, pCONCLUSIONS: Non-Caucasian genotype E was present in the French blood donors. PC mutation was more common than BCP mutations in this study. As HBV infected blood donors were more often asymptomatic carriers, we could speculate that the G1896A mutation may favour the asymptomatic state, supporting previous observations.; Buts du travailPlusieurs études internationales ont décrit une prévalence élevée de la mutation précore G1896A (PC) chez les donneurs de sang. Nous avons mené un projet en collaboration avec l’Institut national de transfusion sanguine sur la prévalence des génotypes et des mutants précore chez les donneurs de sang en France.Patients et méthodesL’effectif comprenait 100donneurs de sang nouvellement dépistés AgHBs positifs. La mutation PC a été recherchée par trois méthodes différentes: une technique de PCR temps réel (PCR TR) développée dans notre laboratoire et ciblée sur la mutation PC, le séquençage direct et l’hybridation moléculaire inverse (Kit Inno-LIPA HBV Precore, INNOGENETICS®).RésultatsLa moyenne d’âge dans la population étudiée était de 30ans (extrêmes 18–64). L’origine géographique était africaine dans 42% des cas. La prévalence de la mutation G1896A isolée ou associée à du virus précore sauvage était de 57% en technique Inno-LIPA et de 59% par séquençage ou PCR TR. Les donneurs infectés par un virus précore muté avaient des charges virales VHB significativement plus basses que les patients porteurs d’un virus sauvage (3,19Log10UI/ml versus 4,93Log10UI/ml, pConclusionsNous confirmons les données de la littérature à savoir une prévalence relativement élevée de mutation PC chez les donneurs de sang français. Sachant que ces sujets sont la plupart du temps asymptomatiques et avec des charges virales VHB inférieures au seuil défini par l’EASL pour le portage inactif, la question du rôle de la mutation G1896A dans la sévérité des lésions hépatiques reste à préciser.

The high heterogeneity of clinical, histological, biological and genetic features in breast cancer is due in part to the extreme molecular complexity of these tumors. This review article presents the major technological advances of the past ten years, in particular the development of microarray approaches, which have enabled genome-wide ("Omics") analysis of these tumors. Numerous genetic and epigenetic alterations involving a small number of altered signalling pathways (PI3K, NK-κB, FGF, etc.) have been described. The next decade will be even more prolific in terms of discovery with the advent of next-generation sequencing (NGS) technologies that will provide fast and low cost constitutional and somatic genome sequences. The full catalogue of somatic genetic alterations will result in a completely new individual management for breast cancer patients.

Weekly phlebotomy schedule is commonly recommended to achieve iron depletion in hereditary hemochromatosis (HH). However, in patients with severe iron overload, more than 2 years may be required, leading to fatigue and lack of compliance. For more than 10 years, we have used erythrocytapheresis (EA) as an alternative treatment.To assess the number of EA to achieve iron depletion and the duration of the iron depletion therapy as well of the tolerance, we retrospectively analysed the data of newly diagnosed hemochromatosis patients, homozygote for the C282Y mutation, followed in our department between 2001 and 2007. EA were performed using a discontinuous or a continuous flow cell separators. The protocol consisted in a bimonthly EA until normalisation of the serum ferritin, with the aim of reducing the patient's hematocrit between 32-35% at the end of each session. Then we performed monthly EA until complete desaturation, defined as serum ferritin concentration below 50 μg/L and transferrin saturation below 40%.Thirty patients were included (23 male, mean age 52 years, range 25-78) and 625 procedures analyzed. The mean volume of removed erythrocytes in each procedure was 416.4 mL (range 150-948), which equals to 374 mg of removed iron. Iron depletion (ferritin50 μg/L) was achieved after 11 months with 20 sessions (range 14-78). No serious adverse reactions or citrate toxicity were observed during and after the apheresis procedures. No specific fatigue was reported during the iron depletion therapy. Patient compliance was 100%. Clinical improvement was noted in 12 out of 18 of symptomatic patients.We conclude that HH patients treated with bimonthly EA achieved iron depletion in less than 1 year under good condition of tolerance. These data support the use of EA in patients with a severe iron overload, since it may reduce the number of the procedures as well as the duration of the iron depletion therapy.

The genetic barrier for the antiretroviral describes the ability to select resistant viruses to this antiretroviral when the viral replication is not controlled. This includes combining several concepts: (1) the number of nucleotide changes required for a resistance mutation, (2) the impact of this mutation on the level of susceptibility to antiretroviral (3) the impact of this mutation on viral replication capacity; all theses conditions influencing the level of resistant variants. The antiretroviral concentration impact also the emergence of resistance. Finally, combine with other molecules, the selection of resistance mutations ton an antiretroviral may differ from one treatment to another. It is recognized that the genetic barrier to lamivudine/emtricitabine, efavirenz and nevirapine is low, and is intermediate for nucleoside such as zidovudine and tenofovir. However, ritonavir boosted protease inhibitor with high plasma concentration have a high genetic barrier. For integrase inhibitors such as raltegravir, the emergence of resistance is certainly faster than the ritonavir boosted protease inhibitors, but seems slower and less systematic than for efavirenz or lamivudine. Many factors could influence the raltegravir resistance such as the level of viral load and replication duration, genetic polymorphism of HIV (integrase gene and other, viral subtype) and the plasma and/or intra- cellular raltegravir concentration.

To screen hepatitis B virus (HBV) genotypes and associated basal core promoter (BCP; T1762A/A1764) and precore (PC; A1896) mutations among the 100 HBV surface antigen (HBsAg) positive voluntary blood donors in France.HBV genotypes were determined by using direct sequence analysis. Three methods were used to detect G1896A mutation: non-commercial real-time PCR (PCRTR°, line probe assay (InnoLiPA HBV PreCore, INNOGENETICS(®)) and direct sequencing of precore gene. HBV viral load was quantified with two commercial real-time PCR (COBAS(®) AmpliPrep/COBAS(®) TaqMan(®) HBV Test/Roche and Real Time HBV/M2000/Abbott).The mean age of donors was 30 (18-64). Patients were from Africa (42%), Europa (50%), and Asia (8%). HBV/D was the most predominant (37%) genotype followed by HBV/A (31%) and HBV/E (22%). PC and BCP mutants were found in 57% with Inno-LIPA HBV test and 59% with both PCRTR and sequencing methods. A significant difference in the viral load of blood donors with wild and PC mutants was observed with the Taqman Cobas real time PCR (3,19 Log(10) UI/ml versus 4,93 Log(10) UI/ml, p 0.05). Precore phenotype determination was in agreement with the three PC mutation detection methods in 56% of cases.Non-Caucasian genotype E was present in the French blood donors. PC mutation was more common than BCP mutations in this study. As HBV infected blood donors were more often asymptomatic carriers, we could speculate that the G1896A mutation may favour the asymptomatic state, supporting previous observations.

International audience; Purpose of review: The present review focuses on recent advances in the knowledge of hereditary optic neuropathies resulting from retinal ganglion cell degeneration, mostly due to mitochondrial dysfunctions.Recent findings: Autosomal dominant optic atrophy, the most common hereditary optic neuropathy, appears to have a more variable clinical presentation than previously thought. Acute visual loss, reversible visual loss, or visual loss associated with extraocular symptoms (deafness, extraocular ophthalmoplegia, multiple sclerosis-like disease) are infrequent, though possible presentations. In Leber's hereditary optic neuropathy, recent findings suggest that the large variability of the clinical expression could be modulated by several factors: genetic (downregulation of the OPA1 gene), environmental (smoking), and anatomic (predisposition of the optic nerve head to axonal loss). Globally, hereditary optic neuropathies may represent an underestimated cause of unexplained and sporadic optic atrophy. Recent advances, such as the discovery of a new gene involved in autosomal recessive optic neuropathy, reinforce the central role played by mitochondrial dysfunctions in the pathogenesis of optic neuropathies. Summary: Hereditary optic neuropathies may have a heterogenous presentation and serve as a paradigm for neurodegenerative diseases affecting mitochondrial structure, plasticity, and function.

A 35-year-old woman is referred for right upper quadrant abdominal pain and fever. She had a cholecystectomy for gallstones 4 years previously. An aunt has also had a cholecystectomy. Abdominal ultrasound examination shows numerous hyperechoic foci within the liver and some "comet tail" artifacts. Because of her age (less than 40), the recurrence of biliary symptoms after cholecystectomy, her family history and the intrahepatic hyperechoic foci, the diagnosis of low phospholipid-associated cholelithiasis (LPAC) syndrome is suspected and confirmed by the demonstration of a point mutation of the ABCB4 gene. Therapy by ursodeoxycholic acid (AUDC) is started. Symptoms improve and they disappear completely within a few weeks. The cause, pathophysiology, diagnosis and treatment are reviewed.