43 research outputs found

    DNM1 encephalopathy: A new disease of vesicle fission.

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    ObjectiveTo evaluate the phenotypic spectrum caused by mutations in dynamin 1 (DNM1), encoding the presynaptic protein DNM1, and to investigate possible genotype-phenotype correlations and predicted functional consequences based on structural modeling.MethodsWe reviewed phenotypic data of 21 patients (7 previously published) with DNM1 mutations. We compared mutation data to known functional data and undertook biomolecular modeling to assess the effect of the mutations on protein function.ResultsWe identified 19 patients with de novo mutations in DNM1 and a sibling pair who had an inherited mutation from a mosaic parent. Seven patients (33.3%) carried the recurrent p.Arg237Trp mutation. A common phenotype emerged that included severe to profound intellectual disability and muscular hypotonia in all patients and an epilepsy characterized by infantile spasms in 16 of 21 patients, frequently evolving into Lennox-Gastaut syndrome. Two patients had profound global developmental delay without seizures. In addition, we describe a single patient with normal development before the onset of a catastrophic epilepsy, consistent with febrile infection-related epilepsy syndrome at 4 years. All mutations cluster within the GTPase or middle domains, and structural modeling and existing functional data suggest a dominant-negative effect on DMN1 function.ConclusionsThe phenotypic spectrum of DNM1-related encephalopathy is relatively homogeneous, in contrast to many other genetic epilepsies. Up to one-third of patients carry the recurrent p.Arg237Trp variant, which is now one of the most common recurrent variants in epileptic encephalopathies identified to date. Given the predicted dominant-negative mechanism of this mutation, this variant presents a prime target for therapeutic intervention

    De novo mutations of KIAA2022 in females cause intellectual disability and intractable epilepsy

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    Background Mutations in the KIAA2022 gene have been reported in male patients with X-linked intellectual disability, and related female carriers were unaffected. Here, we report 14 female patients who carry a heterozygous de novo KIAA2022 mutation and share a phenotype characterised by intellectual disability and epilepsy. Methods Reported females were selected for genetic testing because of substantial developmental problems and/or epilepsy. X-inactivation and expression studies were performed when possible. Results All mutations were predicted to result in a frameshift or premature stop. 12 out of 14 patients had intractable epilepsy with myoclonic and/or absence seizures, and generalised in 11. Thirteen patients had mild to severe intellectual disability. This female phenotype partially overlaps with the reported male phenotype which consists of more severe intellectual disability, microcephaly, growth retardation, facial dysmorphisms and, less frequently, epilepsy. One female patient showed completely skewed X-inactivation, complete absence of RNA expression in blood and a phenotype similar to male patients. In the six other tested patients, X-inactivation was random, confirmed by a non-significant twofold to threefold decrease of RNA expression in blood, consistent with the expected mosaicism between cells expressing mutant or normal KIAA2022 alleles. Conclusions Heterozygous loss of KIAA2022 expression is a cause of intellectual disability in females. Compared with its hemizygous male counterpart, the heterozygous female disease has less severe intellectual disability, but is more often associated with a severe and intractable myoclonic epilepsy

    Implementation and evaluation of a multi-level mental health promotion intervention for the workplace (MENTUPP): study protocol for a cluster randomised controlled trial

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    Background Well-organised and managed workplaces can be a source of wellbeing. The construction, healthcare and information and communication technology sectors are characterised by work-related stressors (e.g. high workloads, tight deadlines) which are associated with poorer mental health and wellbeing. The MENTUPP intervention is a flexibly delivered, multi-level approach to supporting small- and medium-sized enterprises (SMEs) in creating mentally healthy workplaces. The online intervention is tailored to each sector and designed to support employees and leaders dealing with mental health difficulties (e.g. stress), clinical level anxiety and depression, and combatting mental health-related stigma. This paper presents the protocol for the cluster randomised controlled trial (cRCT) of the MENTUPP intervention in eight European countries and Australia. Methods Each intervention country will aim to recruit at least two SMEs in each of the three sectors. The design of the cRCT is based on the experiences of a pilot study and guided by a Theory of Change process that describes how the intervention is assumed to work. SMEs will be randomly assigned to the intervention or control conditions. The aim of the cRCT is to assess whether the MENTUPP intervention is effective in improving mental health and wellbeing (primary outcome) and reducing stigma, depression and suicidal behaviour (secondary outcome) in employees. The study will also involve a process and economic evaluation. Conclusions At present, there is no known multi-level, tailored, flexible and accessible workplace-based intervention for the prevention of non-clinical and clinical symptoms of depression, anxiety and burnout, and the promotion of mental wellbeing. The results of this study will provide a comprehensive overview of the implementation and effectiveness of such an intervention in a variety of contexts, languages and cultures leading to the overall goal of delivering an evidence-based intervention for mental health in the workplace

    16p11.2 600 kb Duplications confer risk for typical and atypical Rolandic epilepsy

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    Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65 046 European population controls (5/393 cases versus 32/65 046 controls; Fisher's exact test P = 2.83 × 10−6, odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 × 10−4). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical R

    Novel Common Genetic Susceptibility Loci for Colorectal Cancer

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    BACKGROUND: Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10-8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. METHODS: We conducted a GWAS in European descent CRC cases and control subjects using a discovery-replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10-8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. RESULTS: The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10-8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. CONCLUSIONS: This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screenin

    Synthesis and Reactivity of an Isolable Cobalt(I) Complex Containing a β-Diketiminate-Based Acyclic Tetradentate Ligand

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    A model for cobalamin was synthesized using a new monoanionic tetradentate nitrogen donor ligand; 2-(4-tolyl)-1,3-bis­(2-isopropylpyridyl)­propenediimine (Tol-BDI<sup>(2‑pp)2</sup>H) (<b>1</b>), which utilizes isopropylpyridines as pendant arms on a β-diketiminate (BDI) backbone. During the synthesis of <b>1</b>, the rearrangement product, Tol-BDI<sup>(2‑pp)(4‑pp)</sup>H (<b>2</b>) was observed. Metalation of <b>1</b> with zinc iodide and cobalt chloride yielded the corresponding Tol-BDI<sup>(2‑pp)2</sup>ZnI (<b>3</b>) and Tol-BDI<sup>(2‑pp)2</sup>CoCl (<b>4</b>) complexes. The redox properties of <b>4</b> in comparison to cobalamin were examined through electrochemical studies. Electrochemical and bulk reduction of complex <b>4</b> gave a diamagnetic cobalt­(I) complex, Tol-BDI<sup>(2‑pp)2</sup>Co (<b>5</b>). Reactivity of <b>5</b> toward C-X bonds was investigated using methyl iodide and 1-iodo-2-(trimethylsilyl)­acetylene, yielding Tol-BDI<sup>(2‑pp)2</sup>Co­(CH<sub>3</sub>)I and Tol-BDI<sup>(2‑pp)2</sup>Co­(C<sub>2</sub>Si­(CH<sub>3</sub>)<sub>3</sub>)I respectively. Synthesis and characterization details for these complexes, including the crystal structure of <b>3</b>, are reported

    Synthesis and Reactivity of an Isolable Cobalt(I) Complex Containing a β-Diketiminate-Based Acyclic Tetradentate Ligand

    No full text
    A model for cobalamin was synthesized using a new monoanionic tetradentate nitrogen donor ligand; 2-(4-tolyl)-1,3-bis­(2-isopropylpyridyl)­propenediimine (Tol-BDI<sup>(2‑pp)2</sup>H) (<b>1</b>), which utilizes isopropylpyridines as pendant arms on a β-diketiminate (BDI) backbone. During the synthesis of <b>1</b>, the rearrangement product, Tol-BDI<sup>(2‑pp)(4‑pp)</sup>H (<b>2</b>) was observed. Metalation of <b>1</b> with zinc iodide and cobalt chloride yielded the corresponding Tol-BDI<sup>(2‑pp)2</sup>ZnI (<b>3</b>) and Tol-BDI<sup>(2‑pp)2</sup>CoCl (<b>4</b>) complexes. The redox properties of <b>4</b> in comparison to cobalamin were examined through electrochemical studies. Electrochemical and bulk reduction of complex <b>4</b> gave a diamagnetic cobalt­(I) complex, Tol-BDI<sup>(2‑pp)2</sup>Co (<b>5</b>). Reactivity of <b>5</b> toward C-X bonds was investigated using methyl iodide and 1-iodo-2-(trimethylsilyl)­acetylene, yielding Tol-BDI<sup>(2‑pp)2</sup>Co­(CH<sub>3</sub>)I and Tol-BDI<sup>(2‑pp)2</sup>Co­(C<sub>2</sub>Si­(CH<sub>3</sub>)<sub>3</sub>)I respectively. Synthesis and characterization details for these complexes, including the crystal structure of <b>3</b>, are reported

    Sorption of Poly- and Perfluoroalkyl Substances (PFASs) Relevant to Aqueous Film-Forming Foam (AFFF)-Impacted Groundwater by Biochars and Activated Carbon

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    Despite growing concerns about human exposure to perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS), other poly- and perfluoroalkyl substances (PFASs) derived from aqueous film-forming foams (AFFFs) have garnered little attention. While these other PFASs may also be present in AFFF-impacted drinking water, their removal by conventional drinking-water treatment is poorly understood. This study compared the removal of 30 PFASs, including 13 recently discovered PFASs, from an AFFF-impacted drinking water using carbonaceous sorbents (i.e., granular activated carbon, GAC). The approach combined laboratory batch experiments and modeling: batch sorption data were used to determine partition coefficients (<i>K</i><sub>d</sub>) and calibrate a transport model based on intraparticle diffusion-limited sorption kinetics, which was used to make forward predictions of PFAS breakthrough during GAC adsorption. While strong retention was predicted for PFOS and PFOA, nearly all of the recently discovered polyfluorinated chemicals and PFOS-like PFASs detected in the AFFF-impacted drinking water were predicted to break through GAC systems before both PFOS and PFOA. These model breakthrough results were used to evaluate a simplified approach to predicting PFAS removal by GAC using compound-specific retention times on a C18 column (RT<sub>C18</sub>). Overall, this study reveals that GAC systems for the treatment of AFFF-impacted sources of water for PFOA and PFOS likely achieve poor removal, when operated only for the treatment of PFOS and PFOA, of many unmonitored PFASs of unknown toxicity
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