60 research outputs found

    Rare deleterious mutations of the gene EFR3A in autism spectrum disorders

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    Background: Whole-exome sequencing studies in autism spectrum disorder (ASD) have identified de novo mutations in novel candidate genes, including the synaptic gene Eighty-five Requiring 3A (EFR3A). EFR3A is a critical component of a protein complex required for the synthesis of the phosphoinositide PtdIns4P, which has a variety of functions at the neural synapse. We hypothesized that deleterious mutations in EFR3A would be significantly associated with ASD. Methods: We conducted a large case/control association study by deep resequencing and analysis of whole-exome data for coding and splice site variants in EFR3A. We determined the potential impact of these variants on protein structure and function by a variety of conservation measures and analysis of the Saccharomyces cerevisiae Efr3 crystal structure. We also analyzed the expression pattern of EFR3A in human brain tissue. Results: Rare nonsynonymous mutations in EFR3A were more common among cases (16 / 2,196 = 0.73%) than matched controls (12 / 3,389 = 0.35%) and were statistically more common at conserved nucleotides based on an experiment-wide significance threshold (P = 0.0077, permutation test). Crystal structure analysis revealed that mutations likely to be deleterious were also statistically more common in cases than controls (P = 0.017, Fisher exact test). Furthermore, EFR3A is expressed in cortical neurons, including pyramidal neurons, during human fetal brain development in a pattern consistent with ASD-related genes, and it is strongly co-expressed (P < 2.2 × 10−16, Wilcoxon test) with a module of genes significantly associated with ASD. Conclusions: Rare deleterious mutations in EFR3A were found to be associated with ASD using an experiment-wide significance threshold. Synaptic phosphoinositide metabolism has been strongly implicated in syndromic forms of ASD. These data for EFR3A strengthen the evidence for the involvement of this pathway in idiopathic autism

    Molecular Cytogenetic Analysis and Resequencing of Contactin Associated Protein-Like 2 in Autism Spectrum Disorders

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    Autism spectrum disorders (ASD) are a group of related neurodevelopmental syndromes with complex genetic etiology.1 We identified a de novo chromosome 7q inversion disrupting Autism susceptibility candidate 2 (AUTS2) and Contactin Associated Protein-Like 2 (CNTNAP2) in a child with cognitive and social delay. We focused our initial analysis on CNTNAP2 based on our demonstration of disruption of Contactin 4 (CNTN4) in a patient with ASD;2 the recent finding of rare homozygous mutations in CNTNAP2 leading to intractable seizures and autism;3 and in situ and biochemical analyses reported herein that confirm expression in relevant brain regions and demonstrate the presence of CNTNAP2 in the synaptic plasma membrane fraction of rat forebrain lysates. We comprehensively resequenced CNTNAP2 in 635 patients and 942 controls. Among patients, we identified a total of 27 nonsynonymous changes; 13 were rare and unique to patients and 8 of these were predicted to be deleterious by bioinformatic approaches and/or altered residues conserved across all species. One variant at a highly conserved position, I869T, was inherited by four affected children in three unrelated families, but was not found in 4010 control chromosomes (p = 0.014). Overall, this resequencing data demonstrated a modest nonsignificant increase in the burden of rare variants in cases versus controls. Nonethless, when viewed in light of two independent studies published in this issue of AJHG showing a relationship between ASD and common CNTNAP2 alleles,4,5 the cytogenetic and mutation screening data suggest that rare variants may also contribute to the pathophysiology of ASD, but place limits on the magnitude of this contribution

    Primary complex motor stereotypies are associated with de novo damaging DNA coding mutations that identify KDM5B as a risk gene.

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    Motor stereotypies are common in children with autism spectrum disorder (ASD), intellectual disability, or sensory deprivation, as well as in typically developing children ("primary" stereotypies, pCMS). The precise pathophysiological mechanism for motor stereotypies is unknown, although genetic etiologies have been suggested. In this study, we perform whole-exome DNA sequencing in 129 parent-child trios with pCMS and 853 control trios (118 cases and 750 controls after quality control). We report an increased rate of de novo predicted-damaging DNA coding variants in pCMS versus controls, identifying KDM5B as a high-confidence risk gene and estimating 184 genes conferring risk. Genes harboring de novo damaging variants in pCMS probands show significant overlap with those in Tourette syndrome, ASD, and those in ASD probands with high versus low stereotypy scores. An exploratory analysis of these pCMS gene expression patterns finds clustering within the cortex and striatum during early mid-fetal development. Exploratory gene ontology and network analyses highlight functional convergence in calcium ion transport, demethylation, cell signaling, cell cycle and development. Continued sequencing of pCMS trios will identify additional risk genes and provide greater insights into biological mechanisms of stereotypies across diagnostic boundaries

    Multiple Recurrent De Novo CNVs, Including Duplications of the 7q11.23 Williams Syndrome Region, Are Strongly Associated with Autism

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    SummaryWe have undertaken a genome-wide analysis of rare copy-number variation (CNV) in 1124 autism spectrum disorder (ASD) families, each comprised of a single proband, unaffected parents, and, in most kindreds, an unaffected sibling. We find significant association of ASD with de novo duplications of 7q11.23, where the reciprocal deletion causes Williams-Beuren syndrome, characterized by a highly social personality. We identify rare recurrent de novo CNVs at five additional regions, including 16p13.2 (encompassing genes USP7 and C16orf72) and Cadherin 13, and implement a rigorous approach to evaluating the statistical significance of these observations. Overall, large de novo CNVs, particularly those encompassing multiple genes, confer substantial risks (OR = 5.6; CI = 2.6–12.0, p = 2.4 × 10-7). We estimate there are 130–234 ASD-related CNV regions in the human genome and present compelling evidence, based on cumulative data, for association of rare de novo events at 7q11.23, 15q11.2-13.1, 16p11.2, and Neurexin 1

    CNDO [complete neglect of differential overlap]/2 studies on ion solvation

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    Antimony Compounds as Flame Retardants for Cotton Textiles

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    30-31<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">To render cotton fabrics fire retardant, three chemical formulations, viz. solvent suspension, emulsion, and titanium-antimony combinations containing some chlorinated compounds, were studied. The treated fabrics were tested for fire performance, tensile strength and effects of laundering. The results show that these treatments could be used to reduce fire hazards in tents, pandals, etc; such treated fabrics may also be useful for military purposes.</span

    Metal Oxide Based Hydroelectric Cell for Electricity Generation by Water Molecule Dissociation without Electrolyte/Acid

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    Never before has electricity been generated out of metal oxides without using any light (UV/IR), acid, or alkali, but it has been achieved by adding a few drops of water on nanoporous metal oxide based Hydroelectric cell (HEC) at room temperature. Electricity generation has been validated and unified for six different metal oxides based on the principle of water dissociation at oxygen deficient nonporous pellet. The presence of oxygen vacancies on the surface of all metal oxide samples has been confirmed by Raman and Photoluminescence spectroscopy techniques. Tin oxide (SnO2) based HEC has delivered maximum power similar to 16.6 mW in a 4.48 cm(2) cell area with highest current 22.2 mA, approximately 2.075 times higher than reported 8 mA current in ferrite based HEC. Water chemidissociation at metal oxide surface was found to be reinforced predominantly by electronegativity of metal cations and oxygen vacancies on nanoporous surface. Divergent peak current values ranging from 22.2 to 1.1 mA were obtained depending on internal resistance, grain boundary nature, water molecule dissociation capability, and nanopores connectivity in different oxides. Slow diffusion of ions in certain metal oxides due to high impedance of grain boundaries has reduced current as confirmed by dielectric and impedance spectroscopy. Metal oxide HEC provides an ecofriendly, cost-effective, and portable green energy source with almost no running cost

    Production of Eruca-Brassica hybrids by embryo rescue

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    Allied species of crop Brassicas have potential value as donors of useful nuclear/organelle genomes. Eruca sativa, a member of subtribe Brassicineae, is resistant to white rust and well adapted to drought. Attempts to hybridize it with Brassica campestris by conventional methods were unsuccessful. However, hybrids were obtained by embryo rescue and the hybrid embryos were found to produce numerous secondary embryos in upto 7 to 8 subcultures. Plantlets developed from them exhibited morphological characteristics of both parents. The chromosome number of 2n=42 showed that they were amphidiploids. The plants were allotctraploids (2n=42) and showed 21 bivalents at M1 of meiosis. Hybridization of total DNA of the hybrids with two probes, a B. campestris tandem repeat DNA and 18s ribosomal DNA of wheat showed that it was derived from the genome of both parents. The hybrids are self-fertile and show the same high fertility even in A3 generation. They were selfed or crossed with B. juncea, B. campestris and B. nigra to screen for useful agronomical traits. Six more embryos of E. saliva × B. campestris have been obtained and their growth is being studied. Preliminary small scale field trials indicate that the selfed hybrid is comparable in yield with a high yielding commercial variety of B. juncea
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