Literature Watch

Evaluation of e-liquid toxicity using an open-source high-throughput screening assay.

Cystic Fibrosis - Wed, 2018-03-28 07:07

Evaluation of e-liquid toxicity using an open-source high-throughput screening assay.

PLoS Biol. 2018 Mar;16(3):e2003904

Authors: Sassano MF, Davis ES, Keating JE, Zorn BT, Kochar TK, Wolfgang MC, Glish GL, Tarran R

Abstract
The e-liquids used in electronic cigarettes (E-cigs) consist of propylene glycol (PG), vegetable glycerin (VG), nicotine, and chemical additives for flavoring. There are currently over 7,700 e-liquid flavors available, and while some have been tested for toxicity in the laboratory, most have not. Here, we developed a 3-phase, 384-well, plate-based, high-throughput screening (HTS) assay to rapidly triage and validate the toxicity of multiple e-liquids. Our data demonstrated that the PG/VG vehicle adversely affected cell viability and that a large number of e-liquids were more toxic than PG/VG. We also performed gas chromatography-mass spectrometry (GC-MS) analysis on all tested e-liquids. Subsequent nonmetric multidimensional scaling (NMDS) analysis revealed that e-liquids are an extremely heterogeneous group. Furthermore, these data indicated that (i) the more chemicals contained in an e-liquid, the more toxic it was likely to be and (ii) the presence of vanillin was associated with higher toxicity values. Further analysis of common constituents by electron ionization revealed that the concentration of cinnamaldehyde and vanillin, but not triacetin, correlated with toxicity. We have also developed a publicly available searchable website (www.eliquidinfo.org). Given the large numbers of available e-liquids, this website will serve as a resource to facilitate dissemination of this information. Our data suggest that an HTS approach to evaluate the toxicity of multiple e-liquids is feasible. Such an approach may serve as a roadmap to enable bodies such as the Food and Drug Administration (FDA) to better regulate e-liquid composition.

PMID: 29584716 [PubMed - in process]

Categories: Literature Watch

Rural Residence and COPD Exacerbations: Analysis of the SPIROMICS Cohort.

Cystic Fibrosis - Wed, 2018-03-28 07:07

Rural Residence and COPD Exacerbations: Analysis of the SPIROMICS Cohort.

Ann Am Thorac Soc. 2018 Mar 27;:

Authors: Burkes RM, Gassett AJ, Ceppe AS, Anderson W, O'Neal WK, Woodruff PG, Krishnan JA, Barr RG, Han MK, Martinez FJ, Comellas AP, Lambert AA, Kaufman JD, Dransfield MT, Wells JM, Kanner RE, Paine R, Bleecker ER, Paulin LM, Hansel NN, Drummond MB, SPIROMICS Investigators

Abstract
RATIONALE: Rural residence is associated with poor outcomes in several chronic diseases. The association between rural residence and chronic obstructive pulmonary disease (COPD) exacerbations remains unclear.
OBJECTIVE: To determine the independent association between rural residence and COPD-related outcomes including COPD exacerbations, airflow obstruction and symptom burden.
METHODS: A total of 1684 Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) participants with FEV1/FVC<0.70 had geocoding-defined rural-urban residence status determined (N=204 rural and N=1480 urban). Univariate and multivariate logistic and negative binomial regressions were performed to assess the independent association between rurality and COPD outcomes including exacerbations, lung function, and symptom burden. The primary exposure of interest was rural residence, determined by geocoding of home address to the block level at time of study enrollment. Additional covariates of interest included demographic and clinical characteristics, occupation, and occupational exposures.The primary outcome measures were exacerbations determined over the one-year course after enrollment by quarterly telephone calls and at an annual research clinic visit. Odds ratio and incidence rate of exacerbations that required treatment with medications including steroids or antibiotics (total exacerbations), and exacerbations leading to hospitalization (severe exacerbations) were determined after adjusting for relevant covariates.
RESULTS: Rural residence was independently associated with 70% increase in odds of total exacerbations [OR 1.70 (95% CI 1.13-2.56); p=0.012] and 46% higher incidence rate of total exacerbations [IRR 1.46 (95% CI 1.02-2.10); p=0.039]. There was no association between rural residence and severe exacerbations. Agricultural occupation was independently associated with increased odds and incidence of total and severe exacerbations. Inclusion of agricultural occupation to analysis attenuated the association between rural residence and odds and incidence rate of total exacerbations [OR 1.52 (95% CI 1.00-2.32; p=0.05) and IRR 1.39 (95% CI 0.97 - 1.99); p=0.07]. There was no difference in symptoms or airflow obstruction between rural and urban participants.
CONCLUSIONS: Rural residence is independently associated with increased odds and incidence of total, but not severe COPD exacerbations. These associations are not fully explained by agriculture-related exposures, highlighting the need for future research into potential mechanisms of increased risk of COPD exacerbations in the rural population.

PMID: 29584453 [PubMed - as supplied by publisher]

Categories: Literature Watch

Genetic and pharmacological inhibition of Cdk1 provides neuroprotection towards ischemic neuronal death.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Genetic and pharmacological inhibition of Cdk1 provides neuroprotection towards ischemic neuronal death.

Cell Death Discov. 2018;4:43

Authors: Marlier Q, Jibassia F, Verteneuil S, Linden J, Kaldis P, Meijer L, Nguyen L, Vandenbosch R, Malgrange B

Abstract
Cell cycle proteins are mainly expressed by dividing cells. However, it is well established that these molecules play additional non-canonical activities in several cell death contexts. Increasing evidence shows expression of cell cycle regulating proteins in post-mitotic cells, including mature neurons, following neuronal insult. Several cyclin-dependent kinases (Cdks) have already been shown to mediate ischemic neuronal death but Cdk1, a major cell cycle G2/M regulator, has not been investigated in this context. We therefore examined the role of Cdk1 in neuronal cell death following cerebral ischemia, using both in vitro and in vivo genetic and pharmacological approaches. Exposure of primary cortical neurons cultures to 4 h of oxygen-glucose deprivation (OGD) resulted in neuronal cell death and induced Cdk1 expression. Neurons from Cdk1-cKO mice showed partial resistance to OGD-induced neuronal cell death. Addition of R-roscovitine to the culture medium conferred neuroprotection against OGD-induced neuronal death. Transient 1-h occlusion of the cerebral artery (MCAO) also leads to Cdk1 expression and activation. Cdk1-cKO mice displayed partial resistance to transient 1-h MCAO. Moreover, systemic delivery of R-roscovitine was neuroprotective following transient 1-h MCAO. This study demonstrates that promising neuroprotective therapies can be considered through inhibition of the cell cycle machinery and particularly through pharmacological inhibition of Cdk1.

PMID: 29581894 [PubMed]

Categories: Literature Watch

Improving imputation in disease-relevant regions: lessons from cystic fibrosis.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Improving imputation in disease-relevant regions: lessons from cystic fibrosis.

NPJ Genom Med. 2018;3:8

Authors: Panjwani N, Xiao B, Xu L, Gong J, Keenan K, Lin F, He G, Baskurt Z, Kim S, Zhang L, Esmaeili M, Blackman S, Scherer SW, Corvol H, Drumm M, Knowles M, Cutting G, Rommens JM, Sun L, Strug LJ

Abstract
Does genotype imputation with public reference panels identify variants contributing to disease? Genotype imputation using the 1000 Genomes Project (1KG; 2504 individuals) displayed poor coverage at the causal cystic fibrosis (CF) transmembrane conductance regulator (CFTR) locus for the International CF Gene Modifier Consortium. Imputation with the larger Haplotype Reference Consortium (HRC; 32,470 individuals) displayed improved coverage but low sensitivity of variants clinically relevant for CF. A hybrid reference that combined whole genome sequencing (WGS) from 101 CF individuals with the 1KG imputed a greater number of single-nucleotide variants (SNVs) that would be analyzed in a genetic association study (r2 ≥ 0.3 and MAF ≥ 0.5%) than imputation with the HRC, while the HRC excelled in the lower frequency spectrum. Using the 1KG or HRC as reference panels missed the most common CF-causing variants or displayed low imputation accuracy. Designs that incorporate population-specific WGS can improve imputation accuracy at disease-specific loci, while imputation using public data sets can omit disease-relevant genotypes.

PMID: 29581887 [PubMed]

Categories: Literature Watch

Structural mechanisms of CFTR function and dysfunction.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Structural mechanisms of CFTR function and dysfunction.

J Gen Physiol. 2018 Mar 26;:

Authors: Hwang TC, Yeh JT, Zhang J, Yu YC, Yeh HI, Destefano S

Abstract
Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel plays a critical role in regulating transepithelial movement of water and electrolyte in exocrine tissues. Malfunction of the channel because of mutations of the cftr gene results in CF, the most prevalent lethal genetic disease among Caucasians. Recently, the publication of atomic structures of CFTR in two distinct conformations provides, for the first time, a clear overview of the protein. However, given the highly dynamic nature of the interactions among CFTR's various domains, better understanding of the functional significance of these structures requires an integration of these new structural insights with previously established biochemical/biophysical studies, which is the goal of this review.

PMID: 29581173 [PubMed - as supplied by publisher]

Categories: Literature Watch

Unconventional Secretion of Transmembrane Proteins.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Unconventional Secretion of Transmembrane Proteins.

Semin Cell Dev Biol. 2018 Mar 23;:

Authors: Gee HY, Kim J, Lee MG

Abstract
Over the past 20 years it has become evident that eukaryotic cells utilize both conventional and unconventional pathways to deliver proteins to their target sites. Most proteins with a signal peptide and/or a transmembrane domain are conventionally transported through the endoplasmic reticulum to the Golgi apparatus and then to the plasma membrane. However, an increasing number of both soluble cargos (Type I, II, and III) and integral membrane proteins (Type IV) have been found to reach the plasma membrane via unconventional protein secretion (UPS) pathways that bypass the Golgi apparatus under certain conditions, such as cellular stress or development. Well-known examples of transmembrane proteins that undergo Type IV UPS pathways are position-specific antigen subunit alpha 1 integrin, cystic fibrosis transmembrane conductance regulator, myeloproliferative leukemia virus oncogene, and pendrin. Although we collectively refer to all Golgi-bypassing routes as UPS, individual trafficking pathways are diverse compared to the conventional pathways, and the molecular mechanisms of UPS pathways are not yet completely defined. This review summarizes the intracellular trafficking pathways of UPS cargo proteins, particularly those with transmembrane domains, and discusses the molecular machinery involved in the UPS of transmembrane proteins.

PMID: 29580969 [PubMed - as supplied by publisher]

Categories: Literature Watch

Sweat test for cystic fibrosis: Wearable sweat sensor vs. standard laboratory test.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Sweat test for cystic fibrosis: Wearable sweat sensor vs. standard laboratory test.

J Cyst Fibros. 2018 Mar 23;:

Authors: Choi DH, Thaxton A, Jeong IC, Kim K, Sosnay PR, Cutting GR, Searson PC

Abstract
BACKGROUND: Sweat chloride testing for diagnosis of cystic fibrosis (CF) involves sweat induction, collection and handling, and measurement in an analytical lab. We have developed a wearable sensor with an integrated salt bridge for real-time measurement of sweat chloride concentration. Here, in a proof-of-concept study, we compare the performance of the sensor to current clinical practice in CF patients and healthy subjects.
METHOD: Sweat was induced on both forearms of 10 individuals with CF and 10 healthy subjects using pilocarpine iontophoresis. A Macroduct sweat collection device was attached to one arm and sweat was collected for 30 min and then sent for laboratory analysis. A sensor was attached to the other arm and the chloride ion concentration monitored in real time for 30 min using a Bluetooth transceiver and smart phone app.
RESULTS: Stable sweat chloride measurements were obtained within 15 min following sweat induction using the wearable sensor. We define the detection time as the time at which the standard deviation of the real-time chloride ion concentration remained below 2 mEq/L for 5 min. The sweat volume for sensor measurements at the detection time was 13.1 ± 11.4 μL (SD), in many cases lower than the minimum sweat volume of 15 μL for conventional testing. The mean difference between sweat chloride concentrations measured by the sensor and the conventional laboratory practice was 6.2 ± 9.5 mEq/L (SD), close to the arm-to-arm variation of about 3 mEq/L. The Pearson correlation coefficient between the two measurements was 0.97 highlighting the excellent agreement between the two methods.
CONCLUSION: A wearable sensor can be used to make real-time measurements of sweat chloride within 15 min following sweat induction, requiring a small sweat volume, and with excellent agreement to standard methods.

PMID: 29580829 [PubMed - as supplied by publisher]

Categories: Literature Watch

Continuous glucose monitoring abnormalities in cystic fibrosis youth correlate with pulmonary function decline.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Continuous glucose monitoring abnormalities in cystic fibrosis youth correlate with pulmonary function decline.

J Cyst Fibros. 2018 Mar 23;:

Authors: Chan CL, Vigers T, Pyle L, Zeitler PS, Sagel SD, Nadeau KJ

Abstract
BACKGROUND: To characterize glucose patterns with continuous glucose monitoring (CGM) in cystic fibrosis (CF) and assess relationships between CGM and clinical outcomes.
METHODS: 110 CF youth and healthy controls (HC), 10-18 years, wore CGM up to 7 days. Correlations between CGM and lung function and BMI z-score change over the prior year were determined.
RESULTS: Multiple CGM measures were higher in CF Normal Glycemic (CFNG) youth versus HC (peak glucose, excursions >140 mg/dl/day, %time > 140 mg/dl, standard deviation (SD) and mean amplitude of glycemic excursions (MAGE)). Hypoglycemia was no different among groups. In CF, decline in FEV1% and FVC% correlated with maximum CGM glucose, excursions >200 mg/dl/day, SD, and MAGE.
CONCLUSIONS: CFNG youth have higher glucoses and glucose variability than HC on CGM. Higher and more variable glucoses correlate with lung function decline. Whether earlier treatment of CGM abnormalities improves lung function in CF requires further study.

PMID: 29580828 [PubMed - as supplied by publisher]

Categories: Literature Watch

A multi-host approach to identify a transposon mutant of Pseudomonas aeruginosa LESB58 lacking full virulence.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

A multi-host approach to identify a transposon mutant of Pseudomonas aeruginosa LESB58 lacking full virulence.

BMC Res Notes. 2018 Mar 27;11(1):198

Authors: Gagné-Thivierge C, Kukavica-Ibrulj I, Filion G, Dekimpe V, Tan SGE, Vincent AT, Déziel É, Levesque RC, Charette SJ

Abstract
OBJECTIVE: Pseudomonas aeruginosa is an opportunistic bacterial pathogen well known to cause chronic lung infections in individuals with cystic fibrosis (CF). Some strains adapted to this particular niche show distinct phenotypes, such as biofilm hyperproduction. It is necessary to study CF clinical P. aeruginosa isolates, such as Liverpool Epidemic Strains (LES), to acquire a better understanding of the key genes essential for in vivo maintenance and the major virulence mechanisms involved in CF lung infections. Previously, a library of 9216 mutants of the LESB58 strain were generated by signature-tagged mutagenesis (STM) and screened in the rat model of chronic lung infection, allowing the identification of 163 STM mutants showing defects in in vivo maintenance.
RESULTS: In the present study, these 163 mutants were successively screened in two additional surrogate host models (the amoeba and the fruit fly). The STM PALES_11731 mutant was the unique non-virulent in the three hosts. A competitive index study in rat lungs confirmed that the mutant was 20-fold less virulent than the wild-type strain. This study demonstrated the pertinence to use a multi-host approach to study the genetic determinants of P. aeruginosa strains infecting CF patients.

PMID: 29580289 [PubMed - in process]

Categories: Literature Watch

Current and future molecular approaches in the diagnosis of cystic fibrosis.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

Current and future molecular approaches in the diagnosis of cystic fibrosis.

Expert Rev Respir Med. 2018 Mar 27;:

Authors: Bergougnoux A, Taulan-Cadars M, Claustres M, Raynal C

Abstract
INTRODUCTION: Cystic Fibrosis is among the first diseases to have general population genetic screening tests and one of the most common indications of prenatal and preimplantation genetic diagnosis for single gene disorders. During the past twenty years, thanks to the evolution of diagnostic techniques, our knowledge of CFTR genetics and pathophysiological mechanisms involved in cystic fibrosis has significantly improved. Areas covered: Sanger sequencing and quantitative methods greatly contributed to the identification of more than 2,000 sequence variations reported worldwide in the CFTR gene. We are now entering a new technological age with the generalization of high throughput approaches such as Next Generation Sequencing and Droplet Digital PCR technologies in diagnostics laboratories. These powerful technologies open up new perspectives for scanning the entire CFTR locus, exploring modifier factors that possibly influence the clinical evolution of patients, and for preimplantation and prenatal diagnosis. Expert commentary: Such breakthroughs would, however, require powerful bioinformatics tools and relevant functional tests of variants for analysis and interpretation of the resulting data. Ultimately, an optimal use of all those resources may improve patient care and therapeutic decision-making.

PMID: 29580110 [PubMed - as supplied by publisher]

Categories: Literature Watch

The Standoff.

Cystic Fibrosis - Wed, 2018-03-28 07:07
Related Articles

The Standoff.

J Am Coll Radiol. 2017 04;14(4):547-548

Authors: Brown SD

PMID: 28274692 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Whole-Genome Linkage Analysis with Whole-Exome Sequencing Identifies a Novel Frameshift Variant in NEFH in a Chinese Family with Charcot-Marie-Tooth 2: A Novel Variant in NEFH for Charcot-Marie-Tooth 2.

Deep learning - Wed, 2018-03-28 07:07

Whole-Genome Linkage Analysis with Whole-Exome Sequencing Identifies a Novel Frameshift Variant in NEFH in a Chinese Family with Charcot-Marie-Tooth 2: A Novel Variant in NEFH for Charcot-Marie-Tooth 2.

Neurodegener Dis. 2018 Mar 27;18(2-3):74-83

Authors: Bian X, Lin P, Li J, Long F, Duan R, Yuan Q, Li Y, Gao F, Gao S, Wei S, Li X, Sun W, Gong Y, Yan C, Liu Q

Abstract
BACKGROUND: Charcot-Marie-Tooth disease (CMT) is the most common neurodegenerative disorder of the peripheral nervous system. More than 50 genes/loci were found associated with the disease. We found a family with autosomal-dominant CMT2.
OBJECTIVE: To reveal the pathogenic gene of the family and further investigate the function of the variant.
METHODS: DNA underwent whole-genome linkage analysis for all family members and whole-exome sequencing for 2 affected members. Neurofilament light polypeptide and wild-type or mutant neurofilament heavy polypeptide (NEFH) were co-transfected into SW13 (vim-) cells. The nefh-knockdown zebrafish model was produced by using morpholino antisense oligonucleotides.
RESULTS: We identified a novel insertion variant (c.3057insG) in NEFH in the family. The variant led to the loss of a stop codon and an extended 41 amino acids in the protein. Immunofluorescence results revealed that mutant NEFH disrupted the neurofilament network and induced aggregation of NEFH protein. Knockdown of nefh in zebrafish caused a slightly or severely curled tail. The motor ability of nefh-knockdown embryos was impaired or even absent, and the embryos showed developmental defects of axons in motor neurons. The abnormal phenotype and axonal developmental defects could be rescued by injection of human wild-type but not human mutant NEFH mRNA.
CONCLUSIONS: We identified a novel stop loss variant in NEFH that is likely pathogenic for CMT2, and the results provide further evidence for the role of an aberrant assembly of neurofilament in CMT.

PMID: 29587262 [PubMed - as supplied by publisher]

Categories: Literature Watch

[EXOME ANALYSIS - A GAME CHANGER IN PEDIATRICS].

Deep learning - Wed, 2018-03-28 07:07

[EXOME ANALYSIS - A GAME CHANGER IN PEDIATRICS].

Harefuah. 2018 Mar;157(3):188-191

Authors: Ta-Shma A, Edvardson S, Elpeleg O, Stepensky P

Abstract
INTRODUCTION: Thirteen years after the completion of the human genome project, the determination of the genomic sequence of the coding parts of the DNA (the exones, hence the exome), has turned into a primary diagnostic tool in daily use in clinical practice. The Department of Genetics at Hadassah was the first in Israel to introduce exome analysis as a robust diagnostic tool into the pediatric departments. Till now 2600 exomes were analyzed at Hadassah, 850 of them in 2016 alone. Exome analysis is cheap and fast, enabling precise and non-invasive diagnosis for a vast array of genetic disorders and congenital malformations. The unique composition of the population which the hospital serves (marked by a high rate of consanguinity) enabled reaching diagnosis in 65% of the cases, twice the rate in medical centers worldwide. The results of this analysis enable genetic counseling to patients' families and prevention of serious disorders. Moreover, the results contribute to the understanding of the biological basis of newly identified disorders and in certain cases assist in the management of the patients. The major limitation of exome analysis is the multitude of identified variants which exist in any individual and which challenge our ability to pick the disease-causing variant. In the case of a disease-causing variant in a new gene, experimental proof is required to validate the causality of the variant; occasionally, an incidental finding with possible clinical significance is identified, raising serious ethical concerns. In this article, we will review the use of this technology through the experience of three pediatric departments at Hadassah.

PMID: 29582952 [PubMed - in process]

Categories: Literature Watch

Whole exome sequencing reveals a novel missense mutation in the MARS gene related to a rare Charcot-Marie-Tooth neuropathy type 2U.

Deep learning - Wed, 2018-03-28 07:07
Related Articles

Whole exome sequencing reveals a novel missense mutation in the MARS gene related to a rare Charcot-Marie-Tooth neuropathy type 2U.

J Peripher Nerv Syst. 2018 Mar 26;:

Authors: Sagi-Dain L, Shemer L, Zelnik N, Zoabi Y, Sadeh O, Adir V, Schif A, Peleg A

Abstract
BACKGROUND: Charcot-Marie-Tooth (CMT) is a heterogeneous group of progressive disorders, characterized by chronic motor and sensory polyneuropathy. This hereditary disorder is related to numerous genes and varying inheritance patterns. Thus, many patients do not reach a final genetic diagnosis.
PATIENT: We describe a 13-years old girl presenting with progressive bilateral leg weakness and gait instability. Extensive laboratory studies and spinal Magnetic resonance imaging scan were normal. Nerve conduction studies revealed severe lower limb peripheral neuropathy with prominent demyelinative component. Following presumptive diagnosis of chronic inflammatory demyelinating polyneuropathy, the patient received treatment with steroids and intravenous immunoglobulins courses for several months, with no apparent improvement.
RESULTS: Whole exome sequencing revealed a novel heterozygous c.2209C>T (p.Arg737Trp) mutation in the MARS gene (OMIM 156560). This gene has recently been related to CMT type 2U. In-silico prediction programs classified this mutation as a probable cause for protein malfunction. Allele frequency data reported this variant in 0.003% of representative Caucasian population. Family segregation analysis study revealed that the patient had inherited the variant from her 60-years old mother, reported as healthy. Neurologic examination of the mother demonstrated decreased tendon reflexes, while nerve conduction studies were consistent with demyelinative and axonal sensory-motor polyneuropathy.
CONCLUSION: Our report highlights the importance of next generation sequencing approach to facilitate the proper molecular diagnosis of highly heterogeneous neurologic disorders. Amongst other numerous benefits, this approach might prevent unnecessary diagnostic testing and potentially harmful medical treatment. Charcot-Marie-Tooth disease (CMT); CMT2U; MARS.

PMID: 29582526 [PubMed - as supplied by publisher]

Categories: Literature Watch

Unexplained cardiac arrest: a tale of conflicting interpretations of KCNQ1 genetic test results.

Deep learning - Wed, 2018-03-28 07:07
Related Articles

Unexplained cardiac arrest: a tale of conflicting interpretations of KCNQ1 genetic test results.

Clin Res Cardiol. 2018 Mar 26;:

Authors: Chua HC, Servatius H, Asatryan B, Schaller A, Rieubland C, Noti F, Seiler J, Roten L, Baldinger SH, Tanner H, Fuhrer J, Haeberlin A, Lam A, Pless SA, Medeiros-Domingo A

Abstract
OBJECTIVE: Unexplained cardiac arrest (UCA) is often the first manifestation of an inherited arrhythmogenic disease. Genetic testing in UCA is challenging due to the complexities of variant interpretation in the absence of supporting cardiac phenotype. We aimed to investigate if a KCNQ1 variant [p.(Pro64_Pro70del)], previously reported as pathogenic, contributes to the long-QT syndrome phenotype, co-segregates with disease or affects KCNQ1 function in vitro.
METHODS: DNA was extracted from peripheral blood of a 22-year-old male after resuscitation from UCA. Targeted exome sequencing was performed using the TruSight-One Sequencing Panel (Illumina). Variants in 190 clinically relevant cardiac genes with minor allele frequency < 1% were analyzed according to the guidelines of the American College of Medical Genetics. Functional characterization was performed using site-directed mutagenesis, expression in Xenopus laevis oocytes using the two-electrode voltage-clamp technique.
RESULTS: The 12-lead ECG, transthoracic echocardiography and coronary angiography after resuscitation showed no specific abnormalities. Two variants were identified: c.190_210del in-frame deletion in KCNQ1 (p.Pro64_Pro70del), reported previously as pathogenic and c.2431C > A in PKP2 (p.Arg811Ser), classified as likely benign. Two asymptomatic family members with no evident phenotype hosted the KCNQ1 variant. Functional studies showed that the wild-type and mutant channels have no significant differences in current levels, conductance-voltage relationships, as well as activation and deactivation kinetics, in the absence and presence of the auxiliary subunit KCNE1.
CONCLUSIONS: Based on our data and previous reports, available evidence is insufficient to consider the variant KCNQ1:c.190_210del as pathogenic. Our findings call for cautious interpretation of genetic tests in UCA in the absence of a clinical phenotype.

PMID: 29582136 [PubMed - as supplied by publisher]

Categories: Literature Watch

Linked homozygous BMPR1B and PDHA2 variants in a consanguineous family with complex digit malformation and male infertility.

Deep learning - Wed, 2018-03-28 07:07
Related Articles

Linked homozygous BMPR1B and PDHA2 variants in a consanguineous family with complex digit malformation and male infertility.

Eur J Hum Genet. 2018 Mar 26;:

Authors: Yıldırım Y, Ouriachi T, Woehlbier U, Ouahioune W, Balkan M, Malik S, Tolun A

Abstract
In affected members of a consanguineous family, a syndrome, which is concurrence of set of medical signs, is often observed and commonly assumed to have arisen from pleiotropy, i.e., the phenomenon of a single gene variant affecting multiple traits. We detected six sibs afflicted with a unique combination of digit malformation that includes brachydactyly, symphalangism and zygodactyly plus infertility in males owing to azoospermia, sperm immotility or necrospermia, which we hypothesised to have arisen from a defect in a single gene. We mapped the disease locus and by exome sequencing identified in patients homozygous missense variants bone morphogenetic protein receptor type IB (BMPR1B) c.640C>T (p.(Arg214Cys)) and alpha-2 pyruvate dehydrogenase (PDHA2) c.679A>G (p.(Met227Val)). Structural protein modelling, protein sequence conservation and in silico analysis indicate that both variants affect protein function. BMPR1B is known to be responsible for autosomal dominant brachydactyly and autosomal recessive acromesomelic chondrodysplasia. Our findings show that also recessive complex digit malformation can be caused by BMPR1B variant and not all biallelic BMPR1B variants cause acromesomelic dysplasia. PDHA2 is a novel candidate gene for male infertility; the protein product is a mitochondrial enzyme with highest expression in ejaculated sperm. Our findings are a unique example of two linked variants, ~ 711 Kb apart, in different genes that together manifest as a novel syndrome. They demonstrate that exome sequencing and not candidate gene approach should be employed in disease gene hunt, defining new diseases and genetic testing, to rule out the coincidental presence of two variants contributing together to the phenotype, which may be discerned as a novel disease.

PMID: 29581481 [PubMed - as supplied by publisher]

Categories: Literature Watch

Whole-exome Sequencing Helps the Diagnosis and Treatment in Children with Neurodevelopmental Delay Accompanied Unexplained Dyspnea.

Deep learning - Wed, 2018-03-28 07:07
Related Articles

Whole-exome Sequencing Helps the Diagnosis and Treatment in Children with Neurodevelopmental Delay Accompanied Unexplained Dyspnea.

Sci Rep. 2018 Mar 26;8(1):5214

Authors: Tong W, Wang Y, Lu Y, Ye T, Song C, Xu Y, Li M, Ding J, Duan Y, Zhang L, Gu W, Zhao X, Yang XA, Jin D

Abstract
Neurodevelopmental delay accompanied unexplained dyspnea is a highly lethal disease in clinic. This study is to investigate the performance characteristics of trio whole exome sequencing (Trio-WES) in a pediatric setting by presenting our patient cohort and displaying the diagnostic yield. A total of 31 pediatric patients showing neurodevelopmental delay accompanied unexplained dyspnea were admitted to our hospital and referred for molecular genetic testing using Trio-WES. Eight genes namely MMACHC, G6PC, G6PT, ETFDH, OTC, NDUFAF5, SLC22A5, and MAGEL2 were suspected to be responsible for the onset of the clinical symptoms and 6 variants were novel. Standard interpretation according to ACMG guideline showed that the variants were pathogenic. Finally, diagnosis of methylmalonic aciduria and homocystinuria, glycogen storage disease, ornithine transcarbamylase deficiency, glutaric acidemia II, mitochondrial complex 1 deficiency, carnitine deficiency, and Schaaf-Yang syndrome was made in 12 out of the 31 patients. Trio-WES is an effective means for molecular diagnosis of infantile neurodevelopmental delay accompanied unexplained dyspnea. As for molecular etiology identification, when routine potential monogenetic inheritance patterns including de novo, autosomal recessive, autosomal dominant, and X-linked recessive inheritance analysis is negative, physicians should take into account imprinted genes.

PMID: 29581464 [PubMed - in process]

Categories: Literature Watch

Nivolumab for Relapsed/Refractory Classic Hodgkin Lymphoma After Failure of Autologous Hematopoietic Cell Transplantation: Extended Follow-Up of the Multicohort Single-Arm Phase II CheckMate 205 Trial.

Drug-induced Adverse Events - Wed, 2018-03-28 07:07

Nivolumab for Relapsed/Refractory Classic Hodgkin Lymphoma After Failure of Autologous Hematopoietic Cell Transplantation: Extended Follow-Up of the Multicohort Single-Arm Phase II CheckMate 205 Trial.

J Clin Oncol. 2018 Mar 27;:JCO2017760793

Authors: Armand P, Engert A, Younes A, Fanale M, Santoro A, Zinzani PL, Timmerman JM, Collins GP, Ramchandren R, Cohen JB, De Boer JP, Kuruvilla J, Savage KJ, Trneny M, Shipp MA, Kato K, Sumbul A, Farsaci B, Ansell SM

Abstract
Purpose Genetic alterations causing overexpression of programmed death-1 ligands are near universal in classic Hodgkin lymphoma (cHL). Nivolumab, a programmed death-1 checkpoint inhibitor, demonstrated efficacy in relapsed/refractory cHL after autologous hematopoietic cell transplantation (auto-HCT) in initial analyses of one of three cohorts from the CheckMate 205 study of nivolumab for cHL. Here, we assess safety and efficacy after extended follow-up of all three cohorts. Methods This multicenter, single-arm, phase II study enrolled patients with relapsed/refractory cHL after auto-HCT treatment failure into cohorts by treatment history: brentuximab vedotin (BV)-naïve (cohort A), BV received after auto-HCT (cohort B), and BV received before and/or after auto-HCT (cohort C). All patients received nivolumab 3 mg/kg every 2 weeks until disease progression/unacceptable toxicity. The primary end point was objective response rate per independent radiology review committee. Results Overall, 243 patients were treated; 63 in cohort A, 80 in cohort B, and 100 in cohort C. After a median follow-up of 18 months, 40% continued to receive treatment. The objective response rate was 69% (95% CI, 63% to 75%) overall and 65% to 73% in each cohort. Overall, the median duration of response was 16.6 months (95% CI, 13.2 to 20.3 months), and median progression-free survival was 14.7 months (95% CI, 11.3 to 18.5 months). Of 70 patients treated past conventional disease progression, 61% of those evaluable had stable or further reduced target tumor burdens. The most common grade 3 to 4 drug-related adverse events were lipase increases (5%), neutropenia (3%), and ALT increases (3%). Twenty-nine deaths occurred; none were considered treatment related. Conclusion With extended follow-up, responses to nivolumab were frequent and durable. Nivolumab seems to be associated with a favorable safety profile and long-term benefits across a broad spectrum of patients with relapsed/refractory cHL.

PMID: 29584546 [PubMed - as supplied by publisher]

Categories: Literature Watch

Upper Airway Stimulation for Obstructive Sleep Apnea: 5-Year Outcomes.

Drug-induced Adverse Events - Wed, 2018-03-28 07:07

Upper Airway Stimulation for Obstructive Sleep Apnea: 5-Year Outcomes.

Otolaryngol Head Neck Surg. 2018 Mar 01;:194599818762383

Authors: Woodson BT, Strohl KP, Soose RJ, Gillespie MB, Maurer JT, de Vries N, Padhya TA, Badr MS, Lin HS, Vanderveken OM, Mickelson S, Strollo PJ

Abstract
Objective To present 5-year outcomes from a prospective cohort of patients with obstructive sleep apnea (OSA) who were treated with upper airway stimulation (UAS) via a unilateral hypoglossal nerve implant. Study Design A multicenter prospective cohort study. Setting Industry-supported multicenter academic and clinical trial. Methods From a cohort of 126 patients, 97 completed protocol, and 71 consented to a voluntary polysomnogram. Those having continuous positive airway pressure failure with moderate to severe OSA, body mass index <32 kg/m2, and no unfavorable collapse on drug-induced sleep endoscopy were enrolled in a phase 3 trial. Prospective outcomes included apnea-hypopnea index (AHI), oxygen desaturation index, and adverse events, as well as measures of sleepiness, quality of life, and snoring. Results Patients who did and did not complete the protocol differed in baseline AHI, oxygen desaturation index, and Functional Outcomes of Sleep Questionnaire scores but not in any other demographics or treatment response measures. Improvement in sleepiness (Epworth Sleepiness Scale) and quality of life was observed, with normalization of scores increasing from 33% to 78% and 15% to 67%, respectively. AHI response rate (AHI <20 events per hour and >50% reduction) was 75% (n = 71). When a last observation carried forward analysis was applied, the responder rate was 63% at 5 years. Serious device-related events all related to lead/device adjustments were reported in 6% of patients. Conclusions Improvements in sleepiness, quality of life, and respiratory outcomes are observed with 5 years of UAS. Serious adverse events are uncommon. UAS is a nonanatomic surgical treatment with long-term benefit for individuals with moderate to severe OSA who have failed nasal continuous positive airway pressure.

PMID: 29582703 [PubMed - as supplied by publisher]

Categories: Literature Watch

Long-term tolerability, immunogenicity and efficacy of Nuwiq® (human-cl rhFVIII) in children with severe haemophilia A.

Drug-induced Adverse Events - Wed, 2018-03-28 07:07
Related Articles

Long-term tolerability, immunogenicity and efficacy of Nuwiq® (human-cl rhFVIII) in children with severe haemophilia A.

Haemophilia. 2018 Mar 26;:

Authors: Klukowska A, Szczepański T, Vdovin V, Knaub S, Bichler J, Jansen M, Dzhunova I, Liesner RJ

Abstract
INTRODUCTION: Nuwiq® (human-cl rhFVIII, simoctocog alfa) is a 4th generation recombinant human FVIII, without chemical modification or fusion with any other protein, produced in a human cell line.
AIM/METHODS: This study (GENA-13) was an extension of the GENA-03 study in which previously treated children aged 2-12 years with severe haemophilia A received Nuwiq® prophylaxis for ≥6 months. GENA-13 examined long-term tolerability, immunogenicity and efficacy of Nuwiq® prophylaxis in children.
RESULTS: Of 59 patients enrolled in GENA-03, 49 continued Nuwiq® prophylaxis in GENA-13 for a median (range) of 30.0 (9.5-52.0) months. No patient withdrew due to drug-related adverse events or developed inhibitors. Only 2 of 20 518 infusions were associated with possibly related adverse events (dyspnoea, fever). The estimated annualized bleeding rate (ABR) was 0.67 (95% CI: 0.44, 1.02) for spontaneous and 2.88 (95% CI: 1.86, 4.46) for all bleeds. Younger children (2-5 years) had lower ABRs than children aged 6-12 years. Annualized bleeding rates were reduced in GENA-13 vs GENA-03, especially for spontaneous bleeds in younger children (71% reduction; ABR ratio 0.29 [95% CI: 0.11, 0.74]). Nuwiq® efficacy was rated as excellent/good in the treatment of 83.0% of 305 evaluated breakthrough bleeds. Surgical prophylaxis with Nuwiq® was rated as excellent for all 17 assessed procedures.
CONCLUSION: Long-term treatment with Nuwiq® for the prevention of bleeds in children with severe haemophilia A was well tolerated, effective and reduced spontaneous bleeding by up to 70% compared with GENA-03.

PMID: 29582516 [PubMed - as supplied by publisher]

Categories: Literature Watch

Pages

Subscribe to Anil Jegga aggregator - Literature Watch