Smith S.B.,University of California at San Francisco |
Qu H.-Q.,McGill University |
Taleb N.,McGill University |
Kishimoto N.Y.,University of California at San Francisco |
And 22 more authors.
Nature | Year: 2010
Insulin from the Β-cells of the pancreatic islets of Langerhans controls energy homeostasis in vertebrates, and its deficiency causes diabetes mellitus. During embryonic development, the transcription factor neurogenin 3 (Neurog3) initiates the differentiation of the Β-cells and other islet cell types from pancreatic endoderm, but the genetic program that subsequently completes this differentiation remains incompletely understood. Here we show that the transcription factor Rfx6 directs islet cell differentiation downstream of Neurog3. Mice lacking Rfx6 failed to generate any of the normal islet cell types except for pancreatic-polypeptide-producing cells. In human infants with a similar autosomal recessive syndrome of neonatal diabetes, genetic mapping and subsequent sequencing identified mutations in the human RFX6 gene. These studies demonstrate a unique position for Rfx6 in the hierarchy of factors that coordinate pancreatic islet development in both mice and humans. Rfx6 could prove useful in efforts to generate Β-cells for patients with diabetes. © 2010 Macmillan Publishers Limited. All rights reserved.
Nizon M.,University of Paris Descartes |
Huber C.,University of Paris Descartes |
De Leonardis F.,University of Pavia |
Merrina R.,University of Paris Descartes |
And 25 more authors.
Human Mutation | Year: 2012
Desbuquois dysplasia (DD) is characterized by antenatal and postnatal short stature, multiple dislocations, and advanced carpal ossification. Two forms have been distinguished on the basis of the presence (type 1) or the absence (type 2) of characteristic hand anomalies. We have identified mutations in calcium activated nucleotidase 1 gene (CANT1) in DD type 1. Recently, CANT1 mutations have been reported in the Kim variant of DD, characterized by short metacarpals and elongated phalanges. DD has overlapping features with spondyloepiphyseal dysplasia with congenital joint dislocations (SDCD) due to Carbohydrate (chondroitin 6) Sulfotransferase 3 (CHST3) mutations. We screened CANT1 and CHST3 in 38 DD cases (6 type 1 patients, 1 Kim variant, and 31 type 2 patients) and found CANT1 mutations in all DD type 1 cases, the Kim variant and in one atypical DD type 2 expanding the clinical spectrum of hand anomalies observed with CANT1 mutations. We also identified in one DD type 2 case CHST3 mutation supporting the phenotype overlap with SDCD. To further define function of CANT1, we studied proteoglycan synthesis in CANT1 mutated patient fibroblasts, and found significant reduced GAG synthesis in presence of β-D-xyloside, suggesting that CANT1 plays a role in proteoglycan metabolism. © 2012 Wiley Periodicals, Inc.
Wilgenhof S.,Laarbeeklaan |
Four S.D.,Laarbeeklaan |
Everaert H.,Nuclear Medicine |
Salmon I.,Hopital Erasme ULB |
Journal of Immunotherapy | Year: 2013
Ipilimumab, a CTLA-4-blocking monoclonal antibody, improved the overall survival (OS) of advanced melanoma patients treated in prospective clinical trials. We here report a study on the outcome of patients with pretreated advanced melanoma offered ipilimumab (at its licensed dose of 3 mg/kg, every 3 wk for a total of 4 doses) in an expanded access program at a single-center university hospital. Of the 50 patients initiating ipilimumab, 31 patients completed induction therapy and 9 patients were offered reinduction therapy. Most immune-related adverse events were mild and reversible. The best objective response rate by mWHO-criteria included 1 complete response and 4 partial responses (best objective response rate of 10%). Two additional patients obtained a partial response by immune-related response criteria. Median OS was 7 months, with a 1- and 2-year survival rate of 45.2% and 28.8%, respectively. Long-term disease control with ipilimumab was observed in 7 patients of which 4 received reinduction. Baseline serum C-reactive protein (CRP) and the absolute lymphocyte count (ALC) measured on week 6 significantly correlated with OS. In conclusion, in this single-center experience with ipilimumab for advanced pretreated melanoma patients, clinical outcome was comparable with the results of published prospective studies. Reinduction therapy was of importance for maintaining long-term disease control in the majority of responding patients. Baseline CRP and ALC at week 6 deserve further prospective evaluation as prognostic and/or predictive (surrogate) markers. Copyright © 2013 by Lippincott Williams & Wilkins.
Le P.Q.,Hopital University Des Enfants Reine Fabiola Ulb |
Gulbis B.,Hopital Erasme U.L.B. |
Dedeken L.,Hopital University Des Enfants Reine Fabiola Ulb |
Dupont S.,Cliniques Universitaires Saint Luc |
And 9 more authors.
Pediatric Blood and Cancer | Year: 2015
Objective: To evaluate the survival of patients with sickle cell disease (SCD) recorded in the Belgian SCD Registry and to assess the impact of disease-modifying treatments (DMT). Method: The Registry created in 2008 included patients of eight centers. All available data in 2008 were retrospectively encoded in the database. After 2008 and until 2012, all data were recorded prospectively for already registered patients as well as newly diagnosed subjects. Data were registered from neonatal screening or from diagnosis (first contact) until last follow-up or death. Data included diagnosis, demography, and outcome data. Results: We collected data from 469 patients over a 5,110 patient years (PY) follow-up period. The global mortality rate was low (0.25/100 PY), although 13 patients died (2.8%) and was similar between children, adolescents (10-18 years), and young adults (P=0.76). Out of the cohort, 185 patients received hydroxyurea at last follow-up (median duration of treatment: 10.3 years), 90 underwent hematopoietic stem cell transplantation (HSCT), 24 were chronically transfused, and 170 had never had any DMT. Hydroxyurea showed significant benefit on patients outcome as reflected by a lower mortality rate compared to transplanted individuals or people without DMT (0.14, 0.36, and 0.38 per 100 PY, respectively) and by higher Kaplan-Meier estimates of 15 year survival (99.4%) compared to HSCT (93.8%; P=0.01) or no DMT groups (95.4%; P=0.04). Conclusion: SCD mortality in Belgium is low with no increase observed in young adults. Patients treated with hydroxyurea demonstrate a significant benefit in survival when compared to those without DMT or transplanted. © 2015 Wiley Periodicals, Inc.
PubMed | Angers University Hospital Center, Leenaards Memory Center, University of Paris Descartes, Hopital Erasme ULB and 2 more.
Type: Clinical Trial, Phase II | Journal: PloS one | Year: 2015
The retest effect-improvement of performance on second exposure to a task-may impede the detection of cognitive decline in clinical trials for neurodegenerative diseases. We assessed the impact of the retest effect in Huntingtons disease trials, and investigated its possible neutralization. We enrolled 54 patients in the Multicentric Intracerebral Grafting in Huntingtons Disease (MIG-HD) trial and 39 in the placebo arm of the Riluzole trial in Huntingtons Disease (RIL-HD). All were assessed with the Unified Huntingtons Disease Rating Scale (UHDRS) plus additional cognitive tasks at baseline (A1), shortly after baseline (A2) and one year later (A3). We used paired t-tests to analyze the retest effect between A1 and A2. For each task of the MIG-HD study, we used a stepwise algorithm to design models predictive of patient performance at A3, which we applied to the RIL-HD trial for external validation. We observed a retest effect in most cognitive tasks. A decline in performance at one year was detected in 3 of the 15 cognitive tasks with A1 as the baseline, and 9 of the 15 cognitive tasks with A2 as the baseline. We also included the retest effect in performance modeling and showed that it facilitated performance prediction one year later for 14 of the 15 cognitive tasks. The retest effect may mask cognitive decline in patients with neurodegenerative diseases. The dual baseline can improve clinical trial design, and better prediction should homogenize patient groups, resulting in smaller numbers of participants being required.
Desir J.,Universitelibre Of Bruxelles Ulb |
Sznajer Y.,Hopital Erasme ULB |
Sznajer Y.,Clinical Genetics Unit |
Depasse F.,Hopital Erasme ULB |
And 5 more authors.
European Journal of Human Genetics | Year: 2010
The latent TGFΒ-binding proteins (LTBPs) and fibrillins are a superfamily of large, multidomain proteins with structural and TGFΒ-signalling roles in the extracellular matrix. Their importance is underscored by fibrillin-1 mutations responsible for Marfan syndrome, but their respective roles are still incompletely understood. We report here on two families where children from healthy, consanguineous parents, presented with megalocornea and impaired vision associated with small, round, dislocated lenses (microspherophakia and ectopia lentis) and myopia, as well as a high-arched palate, and, in older children, tall stature with an abnormally large arm span over body height ratio, that is, associated features of Marfan syndrome. Glaucoma was not present at birth, but was diagnosed in older children. Whole genome homozygosity mapping followed by candidate gene analysis identified homozygous truncating mutations of LTBP2 gene in patients from both families. Fibroblast mRNA analysis was consistent with nonsense-mediated mRNA decay, with no evidence of mutated exon skipping. We conclude that biallelic null LTBP2 mutations cause the ocular phenotype in both families and could lead to Marfan-like features in older children. We suggest that intraocular pressures should be followed-up in young children with an ocular phenotype consisting of megalocornea, spherophakia and/or lens dislocation, and recommend LTBP2 gene analysis in these patients. © 2010 Macmillan Publishers Limited All rights reserved.
PubMed | Hopital Erasme ULB, Ghent University, University Hospitals Leuven and University of Antwerp
Type: Journal Article | Journal: PloS one | Year: 2017
Autosomal dominant retinitis pigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition.Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations.Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5-30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%).Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular spectrum of PRPH2, PRPF8, RHO, RP1, SNRNP200, and TOPORS-associated adRP by the identification of 17 novel mutations.