Molecular characterisation of congenital myasthenic syndromes in Southern Brazil

Objective To perform genetic testing of patients with congenital myasthenic syndromes (CMS) from the Southern Brazilian state of Parana. Patients and methods Twenty-five CMS patients from 18 independent families were included in the study. Known CMS genes were sequenced and restriction digest for the mutation RAPSN p.N88K was performed in all patients. Results We identified recessive mutations of CHRNE in ten families, mutations in DOK7 in three families and mutations in COLQ, CHRNA1 and CHRNB1 in one family each. The mutation CHRNE c. 70insG was found in six families. We have repeatedly identified this mutation in patients from Spain and Portugal and haplotype studies indicate that CHRNE c. 70insG derives from a common ancestor. Conclusions Recessive mutations in CHRNE are the major cause of CMS in Southern Brazil with a common mutation introduced by Hispanic settlers. The second most common cause is mutations in DOK7. The minimum prevalence of CMS in Parana is 0.18/100 000

Molecular characterisation of congenital myasthenic syndromes in Southern Brazil

Objective To perform genetic testing of patients with congenital myasthenic syndromes (CMS) from the Southern Brazilian state of Parana. Patients and methods Twenty-five CMS patients from 18 independent families were included in the study. Known CMS genes were sequenced and restriction digest for the mutation RAPSN p.N88K was performed in all patients. Results We identified recessive mutations of CHRNE in ten families, mutations in DOK7 in three families and mutations in COLQ, CHRNA1 and CHRNB1 in one family each. The mutation CHRNE c. 70insG was found in six families. We have repeatedly identified this mutation in patients from Spain and Portugal and haplotype studies indicate that CHRNE c. 70insG derives from a common ancestor. Conclusions Recessive mutations in CHRNE are the major cause of CMS in Southern Brazil with a common mutation introduced by Hispanic settlers. The second most common cause is mutations in DOK7. The minimum prevalence of CMS in Parana is 0.18/100 000

Dysferlinopathy in Switzerland: clinical phenotypes and potential founder effects.

BACKGROUND: Dysferlin is reduced in patients with limb girdle muscular dystrophy type 2B, Miyoshi myopathy, distal anterior compartment myopathy, and in certain Ethnic clusters. METHODS: We evaluated clinical and genetic patient data from three different Swiss Neuromuscular Centers. RESULTS: Thirteen patients from 6 non-related families were included. Age of onset was 18.8 ± 4.3 years. In all patients, diallelic disease-causing mutations were identified in the DYSF gene. Nine patients from 3 non-related families from Central Switzerland carried the identical homozygous mutation, c.3031 + 2 T>C. A possible founder effect was confirmed by haplotype analysis. Three patients from two different families carried the heterozygous mutation, c.1064_1065delAA. Two novel mutations were identified (c.2869 C>T (p.Gln957Stop), c.5928 G>A (p.Trp1976Stop)). CONCLUSIONS: Our study confirms the phenotypic heterogeneity associated with DYSF mutations. Two mutations (c.3031 + 2 T>C, c.1064_1065delAA) appear common in Switzerland. Haplotype analysis performed on one case (c. 3031 + 2 T>C) suggested a possible founder effect

Obesity-associated melanocortin-4 receptor mutations are associated with changes in the brain response to food cues.

CONTEXT: Mutations in the melanocortin-4 receptor (MC4R) represent the commonest genetic form of obesity and are associated with hyperphagia. OBJECTIVE: The aim of this study was to investigate whether melanocortin signaling modulates anticipatory food reward by studying the brain activation response to food cues in individuals with MC4R mutations. Design/Setting/Participants/Main Outcome Measure: We used functional magnetic resonance imaging to measure blood oxygen level-dependent responses to images of highly palatable, appetizing foods, bland foods, and non-food objects in eight obese individuals with MC4R mutations, 10 equally obese controls, and eight lean controls with normal MC4R genotypes. Based on previous evidence, we performed a region-of-interest analysis centered on the caudate/putamen (dorsal striatum) and ventral striatum. RESULTS: Compared to non-foods, appetizing foods were associated with activation in the dorsal and ventral striatum in lean controls and in MC4R-deficient individuals. Surprisingly, we observed reduced activation of the dorsal and ventral striatum in obese controls relative to MC4R-deficient patients and lean controls. There were no group differences for the contrast of disgusting foods with bland foods or non-foods, suggesting that the effects observed in response to appetizing foods were not related to arousal. CONCLUSION: We identified differences in the striatal response to food cues between two groups of obese individuals, those with and those without MC4R mutations. These findings are consistent with a role for central melanocortinergic circuits in the neural response to visual food cues.This is the final published version. It first appeared at http://press.endocrine.org/doi/abs/10.1210/jc.2014-1651

Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants

Purpose: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases. Methods: We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score &gt; 15 and frequency in GnomAD &lt; 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance. Results: We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients.Discussion: We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications.</p

Protocol for the Cognitive Interventions and Nutritional Supplements (CINS) trial: A randomized controlled multicenter trial of a brief intervention (BI) versus a BI plus cognitive behavioral treatment (CBT) versus nutritional supplements for patients with long-lasting muscle and back pain

Background: Brief intervention programs are clinically beneficial, and cost efficient treatments for low back pain, when offered at 8-12 weeks, compared with treatment as usual. However, about 30% of the patients do not return to work. The European Guidelines for treatment of chronic low back pain recommends Cognitive Behavioral Therapy (CBT), but conclude that further research is needed to evaluate the effectiveness of CBT for chronic low back pain. Methods/Design: The aim of the multicenter CINS trial (Cognitive Interventions and Nutritional Supplements) is to compare the effectiveness of 4 different interventions; Brief Intervention, Brief Intervention and CBT, Brief Intervention and nutritional supplements of seal oil, and Brief Intervention and nutritional supplements of soy oil. All participants will be randomly assigned to the interventions. The nutritional supplements will be tested in a double blind design. 400 patients will be recruited from a population of chronic low back pain patients that have been sick listed for 2-10 months. Four outpatient clinics, located in different parts of Norway, will participate in recruitment and treatment of the patients. The Brief Intervention is a one session cognitive, clinical examination program based on a non-injury model, where return to normal activity and work is the main goal, and is followed by two booster sessions. The CBT is a tailored treatment involving 7 sessions, following a detailed manual. The nutritional supplements consist of a dosage of 10 grams of either soy or seal oil (capsules) per day for 3 months, administered in a double blind design. All patients will be followed up with questionnaires after 3, 6 and 12 months, while sick leave data will be collected up to at least 24 months after randomization. The primary outcome of the study is sick leave and will be based on register data from the National Insurance Administration. Secondary outcomes include self-reported data on disability, pain, and psychological variables. Conclusions: To our knowledge, the CINS trial will be the largest, randomized trial of psychological and nutritional interventions for chronic low back pain patients to date. It will provide important information regarding the effectiveness of CBT and seal oil for chronic low back pain patients

Self-consistent Green's function approaches

We present the fundamental techniques and working equations of many-body Green's function theory for calculating ground state properties and the spectral strength. Green's function methods closely relate to other polynomial scaling approaches discussed in chapters 8 and 10. However, here we aim directly at a global view of the many-fermion structure. We derive the working equations for calculating many-body propagators, using both the Algebraic Diagrammatic Construction technique and the self-consistent formalism at finite temperature. Their implementation is discussed, as well as the inclusion of three-nucleon interactions. The self-consistency feature is essential to guarantee thermodynamic consistency. The pairing and neutron matter models introduced in previous chapters are solved and compared with the other methods in this book.Comment: 58 pages, 14 figures, Submitted to Lect. Notes Phys., "An advanced course in computational nuclear physics: Bridging the scales from quarks to neutron stars", M. Hjorth-Jensen, M. P. Lombardo, U. van Kolck, Editor

Efficient generation of osteoclasts from human induced pluripotent stem cells and functional investigations of lethal CLCN7-related osteopetrosis

Human induced pluripotent stem cells (hiPSCs) hold great potential for modelling human diseases and the development of innovative therapeutic approaches. Here, we report on a novel, simplified differentiation method for forming functional osteoclasts from hiPSCs. The three-step protocol starts with embryoid body formation, followed by hematopoietic specification, and finally osteoclast differentiation. We observed continuous production of monocyte-like cells over a period of up to nine weeks, generating sufficient material for several osteoclast differentiations. The analysis of stage-specific gene and surface marker expression proved mesodermal priming, the presence of monocyte-like cells, and of terminally differentiated multinucleated osteoclasts, able to form resorption pits and trenches on bone and dentine in vitro. In comparison to peripheral blood mononuclear cell (PBMC)-derived osteoclasts hiPSC-derived osteoclasts were larger and contained a higher number of nuclei. Detailed functional studies on the resorption behaviour of hiPSC-osteoclasts indicated a trend towards forming more trenches than pits and an increase in pseudo-resorption. We used hiPSCs from an ARO patient (BIHi002-A, ARO hiPSCs) with compound heterozygous missense mutations p.(G292E) and p.(R403Q) in CLCN7, coding for the Cl(-)/H(+) -exchanger ClC-7, for functional investigations. The patient's leading clinical feature was a brain malformation due to defective neuronal migration. Mutant ClC-7 displayed residual expression and retained lysosomal co-localization with OSTM1, but only ClC-7 harboring the mutation p.(R403Q) gave strongly reduced ion currents. An increased autophagic flux in spite of unchanged lysosomal pH was evident in undifferentiated ARO hiPSCs. ARO hiPSC-derived osteoclasts showed an increased size compared to hiPSCs of healthy donors. They were not able to resorb bone, indicating a loss-of-function effect of the mutations. In summary, we developed a highly reproducible, straightforward hiPSC-osteoclast differentiation protocol. We demonstrated that osteoclasts differentiated from ARO-hiPSCs can be used as a disease model for ARO and potentially also other osteoclast-related diseases

Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants

Purpose: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases. Methods: We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score > 15 and frequency in GnomAD < 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance. Results: We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients. Discussion: We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications

Dwarf galaxy populations in present-day galaxy clusters: I. Abundances and red fractions

We compare the galaxy population in the Virgo, Fornax, Coma and Perseus cluster to a state-of-the-art semi-analytic model, focusing on the regime of dwarf galaxies with luminosities from approximately 10^8 L_sun to 10^9 L_sun. We find that the number density profiles of dwarfs in observed clusters are reproduced reasonably well, and that the red fractions of model clusters provide a good match to Coma and Perseus. On the other hand, the red fraction among dwarf galaxies in Virgo is clearly lower than in model clusters. We argue that this is mainly caused by the treatment of environmental effects in the model. This explanation is supported by our finding that the colours of central ("field") dwarf galaxies are reproduced well, in contrast to previous claims. Finally, we find that the dwarf-to-giant ratio in model clusters is too high. This may indicate that the current model prescription for tidal disruption of faint galaxies is still not efficient enough.Comment: 20 pages, 10 figures. Accepted by MNRAS. Includes the modifications after referee report. Main results unchanged, interpretation slightly change