WorldWideScience

Sample records for strong loss-of-function mutations

  1. A strong loss-of-function mutation in RAN1 results in constitution activation of the ethylene response pathway as well as a rosette-lethal phenotype

    Science.gov (United States)

    Keith Woeste; Joseph J. Kieber

    2000-01-01

    A recessive mutation was identified that constitutively activated the ethylene response pathway in Arabidopsis and resuited in a rosette-lethal phenotype. Positional cloning of the gene corresponding to this mutation revealed that it was allelic to responsive to antagonist1 (ran1), a mutation that causes seedlings to respond in a positive manner to what is normally a...

  2. Filaggrin loss-of-function mutations, atopic dermatitis and risk of actinic keratosis

    DEFF Research Database (Denmark)

    Andersen, Y M F; Egeberg, A; Balslev, E

    2017-01-01

    BACKGROUND: Common loss-of-function mutations in filaggrin gene (FLG) represent a strong genetic risk factor for atopic dermatitis (AD). Homozygous mutation carriers typically display ichthyosis vulgaris (IV) and many have concomitant AD. Previously, homozygous, but not heterozygous, filaggrin gene...

  3. Filaggrin loss-of-function mutations and incident cancer

    DEFF Research Database (Denmark)

    Skaaby, T; Husemoen, L L N; Thyssen, J P

    2014-01-01

    BACKGROUND: Loss-of-function mutations in the filaggrin gene (FLG) could have opposing effects on cancer risk, as mutations are associated with both 10% higher serum vitamin D levels, which may protect against cancer, and with impaired skin barrier function, which may lead to higher cancer...... susceptibility. OBJECTIVES: To investigate the association of the FLG genotype and cancer types in four population-based cohorts. METHODS: A total of 13,376 individuals were genotyped for FLG mutations. Information on cancer was obtained from the Danish Cancer Registry. Persons with a history of cancer...... at baseline were excluded from prospective analyses. RESULTS: There were 1339 incident cancers (median follow-up 11·4 years). The hazard ratios (HRs) and 95% confidence intervals (CIs) for FLG mutation carriers vs. wild types were: for any cancer (HR 0·95, 95% CI 0·78-1·16), any cancer excluding nonmelanoma...

  4. Loss-of-function mutations of STXBP1 in patients with epileptic encephalopathy.

    Science.gov (United States)

    Yamamoto, Toshiyuki; Shimojima, Keiko; Yano, Tamami; Ueda, Yuki; Takayama, Rumiko; Ikeda, Hiroko; Imai, Katsumi

    2016-03-01

    Epileptic encephalopathy, which commences during early infancy, is a severe epileptic syndrome that manifests as age-dependent seizures and severe developmental delay. The syntaxin-binding protein 1 gene (STXBP1) is one of the genes responsible for epileptic encephalopathy. We conducted a cohort study to analyze STXBP1 in 42 patients with epileptic encephalopathy. We identified four novel mutations: two splicing mutations, a frameshift mutation, and a nonsense mutation. All of these mutations were predicted to cause loss-of-function. This result suggests loss-of-function is a common mechanism underlying STXBP1-related epileptic encephalopathy. The four patients showed epileptic features consistent with STXBP1-related epileptic encephalopathy, but showed variable radiological findings, including brain volume loss and myelination delay. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  5. Genotype-phenotype associations in filaggrin loss-of-function mutation carriers

    NARCIS (Netherlands)

    Landeck, Lilla; Visser, Maaike; Kezic, Sanja; John, Swen M.

    2013-01-01

    Loss-of-function mutations in the filaggrin gene (FLG) have been reported to be associated with specific phenotypic characteristics such as hyperlinearity and keratosis pilaris. To study phenotypic features in patients with occupational irritant contact eczema of the hands in relation to FLG

  6. TRPC6 G757D Loss-of-Function Mutation Associates with FSGS

    Science.gov (United States)

    Riehle, Marc; Büscher, Anja K.; Gohlke, Björn-Oliver; Kaßmann, Mario; Kolatsi-Joannou, Maria; Bräsen, Jan H.; Nagel, Mato; Becker, Jan U.; Winyard, Paul; Hoyer, Peter F.; Preissner, Robert; Krautwurst, Dietmar; Gollasch, Maik

    2016-01-01

    FSGS is a CKD with heavy proteinuria that eventually progresses to ESRD. Hereditary forms of FSGS have been linked to mutations in the transient receptor potential cation channel, subfamily C, member 6 (TRPC6) gene encoding a nonselective cation channel. Most of these TRPC6 mutations cause a gain-of-function phenotype, leading to calcium–triggered podocyte cell death, but the underlying molecular mechanisms are unclear. We studied the molecular effect of disease-related mutations using tridimensional in silico modeling of tetrameric TRPC6. Our results indicated that G757 is localized in a domain forming a TRPC6-TRPC6 interface and predicted that the amino acid exchange G757D causes local steric hindrance and disruption of the channel complex. Notably, functional characterization of model interface domain mutants suggested a loss-of-function phenotype. We then characterized 19 human FSGS–related TRPC6 mutations, the majority of which caused gain-of-function mutations. However, five mutations (N125S, L395A, G757D, L780P, and R895L) caused a loss-of-function phenotype. Coexpression of wild-type TRPC6 and TRPC6 G757D, mimicking heterozygosity observed in patients, revealed a dominant negative effect of TRPC6 G757D. Our comprehensive analysis of human disease–causing TRPC6 mutations reveals loss of TRPC6 function as an additional concept of hereditary FSGS and provides molecular insights into the mechanism responsible for the loss-of-function phenotype of TRPC6 G757D in humans. PMID:26892346

  7. Association between loss-of-function mutations in the filaggrin gene and self-reported food allergy and alcohol sensitivity

    DEFF Research Database (Denmark)

    Linneberg, Allan René; Fenger, Runa V; Husemoen, Lise Lotte Nystrup

    2013-01-01

    Loss-of-function mutations of the filaggrin (FLG) gene cause an impaired skin barrier and increase the risk of atopic dermatitis. Interestingly, FLG mutations have also been found to be associated with a high risk of peanut allergy.......Loss-of-function mutations of the filaggrin (FLG) gene cause an impaired skin barrier and increase the risk of atopic dermatitis. Interestingly, FLG mutations have also been found to be associated with a high risk of peanut allergy....

  8. Filaggrin gene loss-of-function mutations explain discordance of atopic dermatitis within dizygotic twin pairs

    DEFF Research Database (Denmark)

    Thomsen, Simon Francis; Elmose, Camilla; Szecsi, Pal Bela

    2016-01-01

    OBJECTIVES: This study was designed to examine the association between loss-of-function mutations in the filaggrin gene (FLG) and atopic dermatitis (AD) and asthma in adult twins. METHODS: A previously well-characterized cohort of 575 adult twins were genotyped for the loss-of-function mutations...... no significant differences in risk for asthma by FLG mutation status in individuals with and without AD, respectively (P-value for interaction, 0.595). In 11 dizygotic twin pairs discordant for FLG mutation status, risk for AD was higher in the twin carrying the FLG mutation (five of 11 [45.5%] twins had...... developed AD) than in the non-carrier co-twin (two of 11 [18.2%] twins had developed AD) (OR 2.50, 95% CI 0.45-13.85; P = 0.293). FLG status did not explain a significant proportion of the variation in AD (P = 0.328) or asthma (P = 0.321). CONCLUSIONS: Filaggrin gene mutations are risk factors...

  9. Filaggrin loss-of-function mutations as risk factors for ischemic stroke in the general population

    DEFF Research Database (Denmark)

    Varbo, A.; Nordestgaard, B. G.; Benn, M.

    2017-01-01

    Essentials FLG mutations cause atopic dermatitis, previously found to be associated with ischemic stroke. Association between FLG mutations and ischemic stroke was examined in 97 174 Danish individuals. FLG mutations were associated with increased ischemic stroke risk in the general population....... The association was most pronounced in younger individuals, and in current and former smokers. Summary: Background Heritability studies have shown a considerable genetic component to ischemic stroke risk; however, much is unknown as to which genes are responsible. Also, previous studies have found an association...... between atopic dermatitis and increased ischemic stroke risk. Objective To test the hypothesis that FLG loss-of-function mutations, known to be associated with atopic dermatitis, were also associated with ischemic stroke. Methods A total of 97 174 individuals, with 3597 cases of ischemic stroke, from...

  10. The spectrum of epilepsy and electroencephalographic abnormalities due to SHANK3 loss-of-function mutations.

    Science.gov (United States)

    Holder, J Lloyd; Quach, Michael M

    2016-10-01

    The coincidence of autism with epilepsy is 27% in those individuals with intellectual disability. 1 Individuals with loss-of-function mutations in SHANK3 have intellectual disability, autism, and variably, epilepsy. 2-5 The spectrum of seizure semiologies and electroencephalography (EEG) abnormalities has never been investigated in detail. With the recent report that SHANK3 mutations are present in approximately 2% of individuals with moderate to severe intellectual disabilities and 1% of individuals with autism, determining the spectrum of seizure semiologies and electrographic abnormalities will be critical for medical practitioners to appropriately counsel the families of patients with SHANK3 mutations. A retrospective chart review was performed of all individuals treated at the Blue Bird Circle Clinic for Child Neurology who have been identified as having either a chromosome 22q13 microdeletion encompassing SHANK3 or a loss-of-function mutation in SHANK3 identified through whole-exome sequencing. For each subject, the presence or absence of seizures, seizure semiology, frequency, age of onset, and efficacy of therapy were determined. Electroencephalography studies were reviewed by a board certified neurophysiologist. Neuroimaging was reviewed by both a board certified pediatric neuroradiologist and child neurologist. There is a wide spectrum of seizure semiologies, frequencies, and severity in individuals with SHANK3 mutations. There are no specific EEG abnormalities found in our cohort, and EEG abnormalities were present in individuals diagnosed with epilepsy and those without history of a clinical seizure. All individuals with a mutation in SHANK3 should be evaluated for epilepsy due to the high prevalence of seizures in this population. The most common semiology is atypical absence seizure, which can be challenging to identify due to comorbid intellectual disability in individuals with SHANK3 mutations; however, no consistent seizure semiology, neuroimaging

  11. PITX2 loss-of-function mutation contributes to tetralogy of Fallot.

    Science.gov (United States)

    Sun, Yu-Min; Wang, Jun; Qiu, Xing-Biao; Yuan, Fang; Xu, Ying-Jia; Li, Ruo-Gu; Qu, Xin-Kai; Huang, Ri-Tai; Xue, Song; Yang, Yi-Qing

    2016-02-15

    Congenital heart disease (CHD) is the most prevalent developmental abnormality in humans and is the most common non-infectious cause of infant morbidity and mortality. Increasing evidence demonstrates that genetic defects are involved in the pathogenesis of CHD. However, CHD is genetically heterogeneous, and the genetic determinants underpinning CHD in most patients remain unknown. In this study, the whole coding region of the PITX2 gene (isoform c) was sequenced in 185 unrelated patients with CHD. The available relatives of a mutation carrier and 300 unrelated healthy individuals used as controls were also genotyped for PITX2. The functional characteristics of the mutation were delineated by using a dual-luciferase reporter assay system. As a result, a novel heterozygous PITX2 mutation, p.Q102L, was identified in a patient with tetralogy of Fallot (TOF). Genetic analysis of the index patient's pedigree showed that the mutation co-segregated with TOF. The mutation was absent in 600 reference chromosomes. Biochemical analysis revealed that the Q102L-mutant PITX2 is associated with significantly reduced transcriptional activity compared with its wild-type counterpart. Furthermore, the mutation markedly decreased the synergistic activation between PITX2 and NKX2-5. This study firstly associates PITX2 loss-of-function mutation with increased susceptibility to TOF, providing novel insight into the molecular mechanism of CHD. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Loss-of-function mutation in ABCA1 and risk of Alzheimer's disease and cerebrovascular disease

    DEFF Research Database (Denmark)

    Nordestgaard, Liv Tybjærg; Tybjærg-Hansen, Anne; Nordestgaard, Børge G

    2015-01-01

    -brain barrier via apoE-mediated pathways. METHODS: We tested whether a loss-of-function mutation in ABCA1, N1800H, is associated with plasma levels of apoE and with risk of Alzheimer's disease (AD) in 92,726 individuals and with risk of cerebrovascular disease in 64,181 individuals. RESULTS: N1800H AC (0.......2%) versus AA (99.8%) was associated with a 13% lower plasma level of apoE (P = 1 × 10(-11)). Multifactorially adjusted hazard ratios for N1800H AC versus AA were 4.13 (95% confidence interval, 1.32-12.9) for AD, 2.46 (1.10-5.50) for cerebrovascular disease, and 8.28 (2.03-33.7) for the hemorrhagic stroke...... subtype. DISCUSSION: A loss-of-function mutation in ABCA1, present in 1:500 individuals, was associated with low plasma levels of apoE and with high risk of AD and cerebrovascular disease in the general population....

  13. A three-dimensional model of mammalian tyrosinase active site accounting for loss of function mutations.

    Science.gov (United States)

    Schweikardt, Thorsten; Olivares, Concepción; Solano, Francisco; Jaenicke, Elmar; García-Borrón, José Carlos; Decker, Heinz

    2007-10-01

    Tyrosinases are the first and rate-limiting enzymes in the synthesis of melanin pigments responsible for colouring hair, skin and eyes. Mutation of tyrosinases often decreases melanin production resulting in albinism, but the effects are not always understood at the molecular level. Homology modelling of mouse tyrosinase based on recently published crystal structures of non-mammalian tyrosinases provides an active site model accounting for loss-of-function mutations. According to the model, the copper-binding histidines are located in a helix bundle comprising four densely packed helices. A loop containing residues M374, S375 and V377 connects the CuA and CuB centres, with the peptide oxygens of M374 and V377 serving as hydrogen acceptors for the NH-groups of the imidazole rings of the copper-binding His367 and His180. Therefore, this loop is essential for the stability of the active site architecture. A double substitution (374)MS(375) --> (374)GG(375) or a single M374G mutation lead to a local perturbation of the protein matrix at the active site affecting the orientation of the H367 side chain, that may be unable to bind CuB reliably, resulting in loss of activity. The model also accounts for loss of function in two naturally occurring albino mutations, S380P and V393F. The hydroxyl group in S380 contributes to the correct orientation of M374, and the substitution of V393 for a bulkier phenylalanine sterically impedes correct side chain packing at the active site. Therefore, our model explains the mechanistic necessity for conservation of not only active site histidines but also adjacent amino acids in tyrosinase.

  14. NALCN channelopathies: Distinguishing gain-of-function and loss-of-function mutations.

    Science.gov (United States)

    Bend, Eric G; Si, Yue; Stevenson, David A; Bayrak-Toydemir, Pinar; Newcomb, Tara M; Jorgensen, Erik M; Swoboda, Kathryn J

    2016-09-13

    To perform genotype-phenotype analysis in an infant with congenital arthrogryposis due to a de novo missense mutation in the NALCN ion channel and explore the mechanism of pathogenicity using a Caenorhabditis elegans model. We performed whole-exome sequencing in a preterm neonate with congenital arthrogryposis and a severe life-threatening clinical course. We examined the mechanism of pathogenicity of the associated NALCN mutation by engineering the orthologous mutation into the nematode C elegans using CRISPR-Cas9. We identified a de novo missense mutation in NALCN, c.1768C>T, in an infant with a severe neonatal lethal form of the recently characterized CLIFAHDD syndrome (congenital contractures of the limbs and face with hypotonia and developmental delay). We report novel phenotypic features including prolonged episodes of stimulus-sensitive sustained muscular contraction associated with life-threatening episodes of desaturation and autonomic instability, extending the severity of previously described phenotypes associated with mutations in NALCN. When engineered into the C elegans ortholog, this mutation results in a severe gain-of-function phenotype, with hypercontraction and uncoordinated movement. We engineered 6 additional CLIFAHDD syndrome mutations into C elegans and the mechanism of action could be divided into 2 categories: half phenocopied gain-of-function mutants and half phenocopied loss-of-function mutants. The clinical phenotype of our patient and electrophysiologic studies show sustained muscular contraction in response to transient sensory stimuli. In C elegans, this mutation causes neuronal hyperactivity via a gain-of-function NALCN ion channel. Testing human variants of NALCN in C elegans demonstrates that CLIFAHDD can be caused by dominant loss- or gain-of-function mutations in ion channel function. © 2016 American Academy of Neurology.

  15. Loss-of-function mutations in HOXC13 cause pure hair and nail ectodermal dysplasia.

    Science.gov (United States)

    Lin, Zhimiao; Chen, Quan; Shi, Lei; Lee, Mingyang; Giehl, Kathrin A; Tang, Zhanli; Wang, Huijun; Zhang, Jie; Yin, Jinghua; Wu, Lingshen; Xiao, Ruo; Liu, Xuanzhu; Dai, Lanlan; Zhu, Xuejun; Li, Ruoyu; Betz, Regina C; Zhang, Xue; Yang, Yong

    2012-11-02

    Pure hair and nail ectodermal dysplasia (PHNED) is a congenital condition characterized by hypotrichosis and nail dystrophy. Autosomal-recessive PHNED has previously been mapped to chromosomal region 12q12-q14.1, which contains the type II hair keratin and HOXC clusters. Hoxc13-null mice are known to develop hair and nail defects very similar to those seen in human PHNED. We performed whole-exome sequencing in a consanguineous Chinese family affected by PHNED and identified a homozygous nonsense mutation (c.390C>A [p.Tyr130(∗)]) in HOXC13 in all affected individuals. In an additional affected female from a consanguineous Afghan family, we found a 27.6 kb homozygous microdeletion involving the first exon of HOXC13. We examined HOXC13 expression in scalp specimen obtained from the index individual of the Chinese family and detected dramatically reduced mRNA levels in skin tissue and nearly absent protein staining in hair follicles, suggesting a mechanism of nonsense-mediated mRNA decay. We also observed markedly decreased expression of four HOXC13 target genes in the specimen. Taken together, our results demonstrate that loss-of-function mutations in HOXC13 cause autosomal-recessive PHNED and further highlight the importance of HOXC13 in hair and nail development. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  16. Loss-of-function mutations in SOX10 cause Kallmann syndrome with deafness.

    Science.gov (United States)

    Pingault, Veronique; Bodereau, Virginie; Baral, Viviane; Marcos, Severine; Watanabe, Yuli; Chaoui, Asma; Fouveaut, Corinne; Leroy, Chrystel; Vérier-Mine, Odile; Francannet, Christine; Dupin-Deguine, Delphine; Archambeaud, Françoise; Kurtz, François-Joseph; Young, Jacques; Bertherat, Jérôme; Marlin, Sandrine; Goossens, Michel; Hardelin, Jean-Pierre; Dodé, Catherine; Bondurand, Nadege

    2013-05-02

    Transcription factor SOX10 plays a role in the maintenance of progenitor cell multipotency, lineage specification, and cell differentiation and is a major actor in the development of the neural crest. It has been implicated in Waardenburg syndrome (WS), a rare disorder characterized by the association between pigmentation abnormalities and deafness, but SOX10 mutations cause a variable phenotype that spreads over the initial limits of the syndrome definition. On the basis of recent findings of olfactory-bulb agenesis in WS individuals, we suspected SOX10 was also involved in Kallmann syndrome (KS). KS is defined by the association between anosmia and hypogonadotropic hypogonadism due to incomplete migration of neuroendocrine gonadotropin-releasing hormone (GnRH) cells along the olfactory, vomeronasal, and terminal nerves. Mutations in any of the nine genes identified to date account for only 30% of the KS cases. KS can be either isolated or associated with a variety of other symptoms, including deafness. This study reports SOX10 loss-of-function mutations in approximately one-third of KS individuals with deafness, indicating a substantial involvement in this clinical condition. Study of SOX10-null mutant mice revealed a developmental role of SOX10 in a subpopulation of glial cells called olfactory ensheathing cells. These mice indeed showed an almost complete absence of these cells along the olfactory nerve pathway, as well as defasciculation and misrouting of the nerve fibers, impaired migration of GnRH cells, and disorganization of the olfactory nerve layer of the olfactory bulbs. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  17. Loss-of-function mutations in SLC30A8 protect against type 2 diabetes

    DEFF Research Database (Denmark)

    Flannick, Jason; Thorleifsson, Gudmar; Beer, Nicola L

    2014-01-01

    Loss-of-function mutations protective against human disease provide in vivo validation of therapeutic targets, but none have yet been described for type 2 diabetes (T2D). Through sequencing or genotyping of ~150,000 individuals across 5 ancestry groups, we identified 12 rare protein-truncating va...

  18. Loss of function mutations of the human melanocortin 1 receptor are common and are associated with red hair.

    Science.gov (United States)

    Schiöth, H B; Phillips, S R; Rudzish, R; Birch-Machin, M A; Wikberg, J E; Rees, J L

    1999-07-05

    The melanocortin 1 receptor is a G-protein-coupled receptor that acts as a control point for control of the eumelanin/phaeomelanin ratio in mouse hair. MC1 receptor loss of function mutations lead to an increase in the ratio of phaeomelanin/eumelanin in many mammals resulting in yellow or red coat colours. We have previously shown that several common point mutations in the human MC1 receptor are overrepresented in North European redheads and in individuals with pale skin. In order to determine the functional significance of these changes we have carried out transfection and binding studies. Expression of the Val60Leu, Arg142His, Arg151Cys, Arg160Trp, and Asp294His receptors in COS 1 cells revealed that these receptors were unable to stimulate cAMP production as strongly as the wild type receptor in response to alpha-melanocyte-stimulating hormone stimulation. None of the mutant receptors displayed complete loss of alphaMSH binding, with only the Arg142His and Asp294His displaying a slight reduction in binding affinity. Copyright 1999 Academic Press.

  19. Loss-of-Function Sodium Channel Mutations in Infancy A Pattern Unfolds

    NARCIS (Netherlands)

    Chockalingam, Priya; Wilde, Arthur A. M.

    2012-01-01

    The role of channelopathies in the pathogenesis of sudden cardiac death (SCD) in patients with structurally normal hearts is a rapidly evolving story.(1) Many ion channels are involved, including loss-of-function sodium channelopathies of which the phenotypic spectrum ranges from lethal arrhythmias

  20. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or ‘classical’ congenital myopathy

    Science.gov (United States)

    Zaharieva, Irina T.; Thor, Michael G.; Oates, Emily C.; van Karnebeek, Clara; Hendson, Glenda; Blom, Eveline; Witting, Nanna; Rasmussen, Magnhild; Gabbett, Michael T.; Ravenscroft, Gianina; Sframeli, Maria; Suetterlin, Karen; Sarkozy, Anna; D’Argenzio, Luigi; Hartley, Louise; Matthews, Emma; Pitt, Matthew; Vissing, John; Ballegaard, Martin; Krarup, Christian; Slørdahl, Andreas; Halvorsen, Hanne; Ye, Xin Cynthia; Zhang, Lin-Hua; Løkken, Nicoline; Werlauff, Ulla; Abdelsayed, Mena; Davis, Mark R.; Feng, Lucy; Phadke, Rahul; Sewry, Caroline A.; Morgan, Jennifer E.; Laing, Nigel G.; Vallance, Hilary; Ruben, Peter; Hanna, Michael G.; Lewis, Suzanne; Kamsteeg, Erik-Jan; Männikkö, Roope

    2016-01-01

    functional assessment in HEK293 cells of the impact of the identified SCN4A mutations showed loss-of-function of the mutant Nav1.4 channels. All, apart from one, of the mutations either caused fully non-functional channels, or resulted in a reduced channel activity. Each of the affected cases carried at least one full loss-of-function mutation. In five out of six families, a second loss-of-function mutation was present on the trans allele. These functional results provide convincing evidence for the pathogenicity of the identified mutations and suggest that different degrees of loss-of-function in mutant Nav1.4 channels are associated with attenuation of the skeletal muscle action potential amplitude to a level insufficient to support normal muscle function. The results demonstrate that recessive loss-of-function SCN4A mutations should be considered in patients with a congenital myopathy. PMID:26700687

  1. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or 'classical' congenital myopathy.

    Science.gov (United States)

    Zaharieva, Irina T; Thor, Michael G; Oates, Emily C; van Karnebeek, Clara; Hendson, Glenda; Blom, Eveline; Witting, Nanna; Rasmussen, Magnhild; Gabbett, Michael T; Ravenscroft, Gianina; Sframeli, Maria; Suetterlin, Karen; Sarkozy, Anna; D'Argenzio, Luigi; Hartley, Louise; Matthews, Emma; Pitt, Matthew; Vissing, John; Ballegaard, Martin; Krarup, Christian; Slørdahl, Andreas; Halvorsen, Hanne; Ye, Xin Cynthia; Zhang, Lin-Hua; Løkken, Nicoline; Werlauff, Ulla; Abdelsayed, Mena; Davis, Mark R; Feng, Lucy; Phadke, Rahul; Sewry, Caroline A; Morgan, Jennifer E; Laing, Nigel G; Vallance, Hilary; Ruben, Peter; Hanna, Michael G; Lewis, Suzanne; Kamsteeg, Erik-Jan; Männikkö, Roope; Muntoni, Francesco

    2016-03-01

    mutations showed loss-of-function of the mutant Nav1.4 channels. All, apart from one, of the mutations either caused fully non-functional channels, or resulted in a reduced channel activity. Each of the affected cases carried at least one full loss-of-function mutation. In five out of six families, a second loss-of-function mutation was present on the trans allele. These functional results provide convincing evidence for the pathogenicity of the identified mutations and suggest that different degrees of loss-of-function in mutant Nav1.4 channels are associated with attenuation of the skeletal muscle action potential amplitude to a level insufficient to support normal muscle function. The results demonstrate that recessive loss-of-function SCN4A mutations should be considered in patients with a congenital myopathy. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

  2. Evidence That Loss-of-Function Filaggrin Gene Mutations Evolved in Northern Europeans to Favor Intracutaneous Vitamin D3 Production

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Bikle, Daniel D; Elias, Peter M

    2014-01-01

    Skin pigmentation lightened progressively to a variable extent, as modern humans emigrated out of Africa, but extreme lightening occurred only in northern Europeans. Yet, loss of pigmentation alone cannot suffice to sustain cutaneous vitamin D3 (VD3) formation at the high latitudes of northern...... Europe. We hypothesized that loss-of-function mutations in the epidermal structural protein, filaggrin (FLG), could have evolved to sustain adequate VD3 status. Loss of FLG results in reduced generation of trans-urocanic acid, the principal endogenous ultraviolet-B (UV-B) filter in lightly-pigmented...... UV-B penetration and intracutaneous VD3 formation, the latitude-dependent gradient in FLG mutations, likely together with other concurrent mutations in VD3 metabolic pathways, provide a non-pigment-based mechanism that sustains higher levels of circulating VD3 in northern Europeans. At the time...

  3. Endogenous network states predict gain or loss of functions for genetic mutations in hepatocellular carcinoma

    Science.gov (United States)

    Wang, Gaowei; Su, Hang; Yu, Helin; Yuan, Ruoshi; Zhu, Xiaomei; Ao, Ping

    2016-01-01

    Cancers have been typically characterized by genetic mutations. Patterns of such mutations have traditionally been analysed by posteriori statistical association approaches. One may ponder the possibility of a priori determination of any mutation regularity. Here by exploring biological processes implied in a mechanistic theory recently developed (the endogenous molecular–cellular network theory), we found that the features of genetic mutations in cancers may be predicted without any prior knowledge of mutation propensities. With hepatocellular carcinoma (HCC) as an example, we found that the normal hepatocyte and cancerous hepatocyte can be represented by robust stable states of one single endogenous network. These stable states, specified by distinct patterns of expressions or activities of proteins in the network, provide means to directly identify a set of most probable genetic mutations and their effects in HCC. As the key proteins and main interactions in the network are conserved through cell types in an organism, similar mutational features may also be found in other cancers. This analysis yielded straightforward and testable predictions on accumulated and preferred mutation spectra in normal tissue. The validation of predicted cancer state mutation patterns demonstrates the usefulness and potential of a causal dynamical framework to understand and predict genetic mutations in cancer. PMID:26911487

  4. Endogenous network states predict gain or loss of functions for genetic mutations in hepatocellular carcinoma.

    Science.gov (United States)

    Wang, Gaowei; Su, Hang; Yu, Helin; Yuan, Ruoshi; Zhu, Xiaomei; Ao, Ping

    2016-02-01

    Cancers have been typically characterized by genetic mutations. Patterns of such mutations have traditionally been analysed by posteriori statistical association approaches. One may ponder the possibility of a priori determination of any mutation regularity. Here by exploring biological processes implied in a mechanistic theory recently developed (the endogenous molecular-cellular network theory), we found that the features of genetic mutations in cancers may be predicted without any prior knowledge of mutation propensities. With hepatocellular carcinoma (HCC) as an example, we found that the normal hepatocyte and cancerous hepatocyte can be represented by robust stable states of one single endogenous network. These stable states, specified by distinct patterns of expressions or activities of proteins in the network, provide means to directly identify a set of most probable genetic mutations and their effects in HCC. As the key proteins and main interactions in the network are conserved through cell types in an organism, similar mutational features may also be found in other cancers. This analysis yielded straightforward and testable predictions on accumulated and preferred mutation spectra in normal tissue. The validation of predicted cancer state mutation patterns demonstrates the usefulness and potential of a causal dynamical framework to understand and predict genetic mutations in cancer. © 2016 The Author(s).

  5. The hands in health and disease of individuals with filaggrin loss-of-function mutations

    DEFF Research Database (Denmark)

    Kaae, Jeanette; Menné, Torkil; Carlsen, Berit C

    2012-01-01

    During the last 2 years, we have performed filaggrin genotyping in patients with eczema seen in our hand eczema clinic. We present pictures of healthy and diseased hands from individuals with filaggrin gene (FLG) mutations to describe a clinical entity of hand eczema. We show that xerosis...... and hyperkeratosis on the dorsal aspects of the hands and fingers, as well as palmar hyperlinearity, should alert the clinician about a possible inherited barrier abnormality of the skin resulting from FLG mutations. The series of photographs range from the hands of an individual with FLG mutations but no history...... of eczema, to the hands of individuals with typical and atypical filaggrin hand eczema, and finally to the hands of an individual with FLG mutations and hand eczema caused by exposure to irritants and allergens. We briefly discuss this possible subtype of hand eczema, present pathomechanisms, and indicate...

  6. Loss-of-function CARD8 mutation causes NLRP3 inflammasome activation and Crohn's disease.

    Science.gov (United States)

    Mao, Liming; Kitani, Atsushi; Similuk, Morgan; Oler, Andrew J; Albenberg, Lindsey; Kelsen, Judith; Aktay, Atiye; Quezado, Martha; Yao, Michael; Montgomery-Recht, Kim; Fuss, Ivan J; Strober, Warren

    2018-02-06

    In these studies we evaluated the contribution of the NLRP3 inflammasome to Crohn's disease (CD) in a kindred containing individuals having a missense mutation in CARD8, a protein known to inhibit this inflammasome. Whole exome sequencing and PCR studies identified that the affected individuals had a V44I mutation in a single allele of the T60 isoform of CARD8. The serum levels of IL-1β in the affected individuals were increased compared with that in healthy controls and their peripheral monocytes produced increased amounts of IL-1β when stimulated by NLRP3 activators. Immunoblot studies probing the basis of these findings showed that mutated T60 CARD8 fails to down-regulate the NLRP3 inflammasome because it does not bind to NLRP3 and inhibit its oligomerization. In addition, these studies showed that mutated T60 CARD8 exerts a dominant negative effect by its capacity to bind to and form oligomers with unmutated T60 or T48 CARD8 that impede their binding to NLRP3. Finally, inflammasome activation studies revealed that intact but not mutated CARD8 prevents NLRP3 deubiquitination and serine dephosphorylation. CD due to a CARD8 mutation was not effectively treated by anti-TNF-α, but did respond to IL-1β inhibitors. Thus, patients with anti-TNF-α-resistant CD may respond to this treatment option.

  7. Loss-of-Function and Gain-of-Function Mutations in KCNQ5 Cause Intellectual Disability or Epileptic Encephalopathy.

    Science.gov (United States)

    Lehman, Anna; Thouta, Samrat; Mancini, Grazia M S; Naidu, Sakkubai; van Slegtenhorst, Marjon; McWalter, Kirsty; Person, Richard; Mwenifumbo, Jill; Salvarinova, Ramona; Guella, Ilaria; McKenzie, Marna B; Datta, Anita; Connolly, Mary B; Kalkhoran, Somayeh Mojard; Poburko, Damon; Friedman, Jan M; Farrer, Matthew J; Demos, Michelle; Desai, Sonal; Claydon, Thomas

    2017-07-06

    KCNQ5 is a highly conserved gene encoding an important channel for neuronal function; it is widely expressed in the brain and generates M-type current. Exome sequencing identified de novo heterozygous missense mutations in four probands with intellectual disability, abnormal neurological findings, and treatment-resistant epilepsy (in two of four). Comprehensive analysis of this potassium channel for the four variants expressed in frog oocytes revealed shifts in the voltage dependence of activation, including altered activation and deactivation kinetics. Specifically, both loss-of-function and gain-of-function KCNQ5 mutations, associated with increased excitability and decreased repolarization reserve, lead to pathophysiology. Copyright © 2017 American Society of Human Genetics. All rights reserved.

  8. ITGB6 loss-of-function mutations cause autosomal recessive amelogenesis imperfecta.

    Science.gov (United States)

    Wang, Shih-Kai; Choi, Murim; Richardson, Amelia S; Reid, Bryan M; Lin, Brent P; Wang, Susan J; Kim, Jung-Wook; Simmer, James P; Hu, Jan C-C

    2014-04-15

    Integrins are cell-surface adhesion receptors that bind to extracellular matrices (ECM) and mediate cell-ECM interactions. Some integrins are known to play critical roles in dental enamel formation. We recruited two Hispanic families with generalized hypoplastic amelogenesis imperfecta (AI). Analysis of whole-exome sequences identified three integrin beta 6 (ITGB6) mutations responsible for their enamel malformations. The female proband of Family 1 was a compound heterozygote with an ITGB6 transition mutation in Exon 4 (g.4545G > A c.427G > A p.Ala143Thr) and an ITGB6 transversion mutation in Exon 6 (g.27415T > A c.825T > A p.His275Gln). The male proband of Family 2 was homozygous for an ITGB6 transition mutation in Exon 11 (g.73664C > T c.1846C > T p.Arg616*) and hemizygous for a transition mutation in Exon 6 of Nance-Horan Syndrome (NHS Xp22.13; g.355444T > C c.1697T > C p.Met566Thr). These are the first disease-causing ITGB6 mutations to be reported. Immunohistochemistry of mouse mandibular incisors localized ITGB6 to the distal membrane of differentiating ameloblasts and pre-ameloblasts, and then ITGB6 appeared to be internalized by secretory stage ameloblasts. ITGB6 expression was strongest in the maturation stage and its localization was associated with ameloblast modulation. Our findings demonstrate that early and late amelogenesis depend upon cell-matrix interactions. Our approach (from knockout mouse phenotype to human disease) demonstrates the power of mouse reverse genetics in mutational analysis of human genetic disorders and attests to the need for a careful dental phenotyping in large-scale knockout mouse projects.

  9. De novo loss-of-function mutations in WAC cause a recognizable intellectual disability syndrome and learning deficits in Drosophila.

    Science.gov (United States)

    Lugtenberg, Dorien; Reijnders, Margot R F; Fenckova, Michaela; Bijlsma, Emilia K; Bernier, Raphael; van Bon, Bregje W M; Smeets, Eric; Vulto-van Silfhout, Anneke T; Bosch, Danielle; Eichler, Evan E; Mefford, Heather C; Carvill, Gemma L; Bongers, Ernie M H F; Schuurs-Hoeijmakers, Janneke Hm; Ruivenkamp, Claudia A; Santen, Gijs W E; van den Maagdenberg, Arn M J M; Peeters-Scholte, Cacha M P C D; Kuenen, Sabine; Verstreken, Patrik; Pfundt, Rolph; Yntema, Helger G; de Vries, Petra F; Veltman, Joris A; Hoischen, Alexander; Gilissen, Christian; de Vries, Bert B A; Schenck, Annette; Kleefstra, Tjitske; Vissers, Lisenka E L M

    2016-08-01

    Recently WAC was reported as a candidate gene for intellectual disability (ID) based on the identification of a de novo mutation in an individual with severe ID. WAC regulates transcription-coupled histone H2B ubiquitination and has previously been implicated in the 10p12p11 contiguous gene deletion syndrome. In this study, we report on 10 individuals with de novo WAC mutations which we identified through routine (diagnostic) exome sequencing and targeted resequencing of WAC in 2326 individuals with unexplained ID. All but one mutation was expected to lead to a loss-of-function of WAC. Clinical evaluation of all individuals revealed phenotypic overlap for mild ID, hypotonia, behavioral problems and distinctive facial dysmorphisms, including a square-shaped face, deep set eyes, long palpebral fissures, and a broad mouth and chin. These clinical features were also previously reported in individuals with 10p12p11 microdeletion syndrome. To investigate the role of WAC in ID, we studied the importance of the Drosophila WAC orthologue (CG8949) in habituation, a non-associative learning paradigm. Neuronal knockdown of Drosophila CG8949 resulted in impaired learning, suggesting that WAC is required in neurons for normal cognitive performance. In conclusion, we defined a clinically recognizable ID syndrome, caused by de novo loss-of-function mutations in WAC. Independent functional evidence in Drosophila further supported the role of WAC in ID. On the basis of our data WAC can be added to the list of ID genes with a role in transcription regulation through histone modification.

  10. Characterizations of a loss-of-function mutation in the Kir3.4 channel subunit

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Ravn, Lasse Steen; Schmitt, Nicole

    2007-01-01

    and two-electrode voltage-clamp revealed that Kir3.4-G247R basal current was reduced compared to wild-type Kir3.4 and co-expression with the muscarinic acetylcholine receptor type 2 showed that also the acetylcholine induced current was severely reduced in Kir3.4-G247R, indicating that the mutation...... the lack of clear clinical manifestations and further studies are necessary to elucidate if mutations in Kir3.4 are predisposing AF. Udgivelsesdato: 2007-Dec-28...

  11. Novel missense loss-of-function mutations of WNT1 in an autosomal recessive Osteogenesis imperfecta patient.

    Science.gov (United States)

    Won, Joon Yeon; Jang, Woo Young; Lee, Hye-Ran; Park, Seon Young; Kim, Woo-Young; Park, Jong Hoon; Kim, Yonghwan; Cho, Tae-Joon

    2017-08-01

    Osteogenesis imperfecta (OI) is a heritable skeletal disorder characterized by bone fragility and low bone mass. Recently, loss-of-function mutations of WNT1 have been reported to be causative in OI or osteoporosis. We report an OI patient with novel compound heterozygous WNT1 missense mutations, p.Glu123Asp and p.Cys153Gly. Both mutations are found in the exon 3, and the p.Glu123Asp is the most proximal N-terminus missense mutation among the reported WNT1 missense mutations in OI patients. In vitro functional analysis reveals that while expression of wildtype WNT1 stimulates canonical WNT1-mediated β-catenin signaling, that of individual WNT1 mutant fails to do so, indicative of the pathogenic nature of the WNT1 variants. Although the pathogenic mechanism of WNT1 defects in OI has yet to be uncovered, these findings further contribute to the implications and importance of functional relevance of WNT1 in skeletal disorders. Copyright © 2017. Published by Elsevier Masson SAS.

  12. Arrhythmogenic cardiomyopathy in a patient with a rare loss-of-function KCNQ1 mutation.

    Science.gov (United States)

    Xiong, Qinmei; Cao, Qing; Zhou, Qiongqiong; Xie, Jinyan; Shen, Yang; Wan, Rong; Yu, Jianhua; Yan, Sujuan; Marian, Ali J; Hong, Kui

    2015-01-23

    Ventricular tachycardia (VT) is a common manifestation of advanced cardiomyopathies. In a subset of patients with dilated cardiomyopathy, VT is the initial and the cardinal manifestation of the disease. The molecular genetic basis of this subset of dilated cardiomyopathy is largely unknown. We identified 10 patients with dilated cardiomyopathy who presented with VT and sequenced 14 common causal genes for cardiomyopathies and arrhythmias. Functional studies included cellular patch clamp, confocal microscopy, and immunoblotting. We identified nonsynonymous variants in 4 patients, including a rare missense p.R397Q mutation in the KCNQ1 gene in a 60-year-old man who presented with incessant VT and had mild cardiac dysfunction. The p.R397Q mutation was absent in an ethnically matched control group, affected a conserved amino acid, and was predicted by multiple algorithms to be pathogenic. Co-expression of the mutant KCNQ1 with its partner unit KCNE1 was associated with reduced tail current density of slowly activating delayed rectifier K(+) current (IKs). The mutation reduced membrane localization of the protein. Dilated cardiomyopathy with an initial presentation of VT may be a forme fruste of arrhythmogenic cardiomyopathy caused by mutations in genes encoding the ion channels. The findings implicate KCNQ1 as a possible causal gene for arrhythmogenic cardiomyopathy. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  13. A hotspot in the glucocorticoid receptor DNA-binding domain susceptible to loss of function mutation.

    Science.gov (United States)

    Banuelos, Jesus; Shin, Soon Cheon; Lu, Nick Z

    2015-04-01

    Glucocorticoids (GCs) are used to treat a variety of inflammatory disorders and certain cancers. However, GC resistance occurs in subsets of patients. We found that EL4 cells, a GC-resistant mouse thymoma cell line, harbored a point mutation in their GC receptor (GR) gene, resulting in the substitution of arginine 493 by a cysteine in the second zinc finger of the DNA-binding domain. Allelic discrimination analyses revealed that the R493C mutation occurred on both alleles. In the absence of GCs, the GR in EL4 cells localized predominantly in the cytoplasm and upon dexamethasone treatment underwent nuclear translocation, suggesting that the ligand binding ability of the GR in EL4 cells was intact. In transient transfection assays, the R493C mutant could not transactivate the MMTV-luciferase reporter. Site-directed mutagenesis to revert the R493C mutation restored the transactivation activity. Cotransfection experiments showed that the R493C mutant did not inhibit the transcriptional activities of the wild-type GR. In addition, the R493C mutant did not repress either the AP-1 or NF-κB reporters as effectively as WT GR. Furthermore, stable expression of the WT GR in the EL4 cells enabled GC-mediated gene regulation, specifically upregulation of IκBα and downregulation of interferon γ and interleukin 17A. Arginine 493 is conserved among multiple species and all human nuclear receptors and its mutation has also been found in the human GR, androgen receptor, and mineralocorticoid receptor. Thus, R493 is necessary for the transcriptional activity of the GR and a hotspot for mutations that result in GC resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Increased ethanol consumption despite taste aversion in mice with a human tryptophan hydroxylase 2 loss of function mutation.

    Science.gov (United States)

    Lemay, Francis; Doré, François Y; Beaulieu, Jean-Martin

    2015-11-16

    Polymorphisms in the gene encoding the brain serotonin synthesis enzyme Tph2 have been identified in mental illnesses, with co-morbidity of substance use disorder. However, little is known about the impact of Tph2 gene variants on addiction. Mice expressing a human Tph2 loss of function variant were used to investigate consequences of aversive conditions on ethanol intake. Mice were familiarized either with ethanol or a solution containing both ethanol and the bittering agent quinine. Effect of familiarization to ethanol or an ethanol-quinine solution was then evaluated using a two-bottles preference test in Tph2-KI and control littermates. Mice from both genotypes displayed similar levels of ethanol consumption and quinine avoidance when habituated to ethanol alone. In contrast, addition of quinine to ethanol during the familiarization period resulted in a reduction of avoidance for the quinine-ethanol solution only in mutant mice. These results indicate that loss of function mutation in Tph2 results in greater motivation for ethanol consumption under aversive conditions and may confer enhanced sensitivity to alcohol use disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Loss-of-Function Mutations in SERPINB8 Linked to Exfoliative Ichthyosis with Impaired Mechanical Stability of Intercellular Adhesions.

    Science.gov (United States)

    Pigors, Manuela; Sarig, Ofer; Heinz, Lisa; Plagnol, Vincent; Fischer, Judith; Mohamad, Janan; Malchin, Natalia; Rajpopat, Shefali; Kharfi, Monia; Lestringant, Giles G; Sprecher, Eli; Kelsell, David P; Blaydon, Diana C

    2016-08-04

    SERPINS comprise a large and functionally diverse family of serine protease inhibitors. Here, we report three unrelated families with loss-of-function mutations in SERPINB8 in association with an autosomal-recessive form of exfoliative ichthyosis. Whole-exome sequencing of affected individuals from a consanguineous Tunisian family and a large Israeli family revealed a homozygous frameshift mutation, c.947delA (p.Lys316Serfs(∗)90), and a nonsense mutation, c.850C>T (p.Arg284(∗)), respectively. These two mutations are located in the last exon of SERPINB8 and, hence, would not be expected to lead to nonsense-mediated decay of the mRNA; nonetheless, both mutations are predicted to lead to loss of the reactive site loop of SERPINB8, which is crucial for forming the SERPINB8-protease complex. Using Sanger sequencing, a homozygous missense mutation, c.2T>C (p.Met1?), predicted to result in an N-terminal truncated protein, was identified in an additional family from UAE. Histological analysis of a skin biopsy from an individual homozygous for the variant p.Arg284(∗) showed disadhesion of keratinocytes in the lower epidermal layers plus decreased SERPINB8 levels compared to control. In vitro studies utilizing siRNA-mediated knockdown of SERPINB8 in keratinocytes demonstrated that in the absence of the protein, there is a cell-cell adhesion defect, particularly when cells are subjected to mechanical stress. In addition, immunoblotting and immunostaining revealed an upregulation of desmosomal proteins. In conclusion, we report mutations in SERPINB8 that are associated with exfoliative ichthyosis and provide evidence that SERPINB8 contributes to the mechanical stability of intercellular adhesions in the epidermis. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  16. Skeletal muscle myopathy mutations at the actin tropomyosin interface that cause gain- or loss-of-function.

    Science.gov (United States)

    Memo, Massimiliano; Marston, Steven

    2013-08-01

    It is well known that the regulation of muscle contraction relies on the ability of tropomyosin to switch between different positions on the actin filament, but it is still not well understood which amino acids are directly involved in the different states of the interaction. Recently the structure of the actin-tropomyosin interface has been determined both in the absence and presence of myosin heads. Interestingly, a number of mutations in tropomyosin that are associated with skeletal muscle myopathy are located within this interface. We first give an overview of the functional effect of mutations on amino acids that are involved in the contact with actin asp25, which represent a pattern repeated seven times along tropomyosin. It is explained how some of these amino acids (R167 and R244) which are thought to be involved in a salt bridge contact with actin in the closed state can produce a loss-of-function when mutated, while other positively charged tropomyosin amino acids positioned on the downstream side of the contact (K7, K49, R91, K168) can produce a gain-of-function when mutated. We then consider mutations of amino acids involved in another salt bridge contact between the two proteins in the closed state, actin K326N (which binds on five different points of tropomyosin) and tropomyosin ∆E139 and E181K, and we report how all of these mutations produce a gain-of-function. These observations can be important to validate the proposed structures and to understand more deeply how mutations affect the function of these proteins and to enable prediction of their outcomes.

  17. Filaggrin loss-of-function mutations are not associated with atopic dermatitis that develops in late childhood or adulthood.

    Science.gov (United States)

    Rupnik, H; Rijavec, M; Korošec, P

    2015-02-01

    The influence of filaggrin gene (FLG) mutations on early- vs. late-onset development of atopic dermatitis (AD), allergic contact dermatitis (ACD) and chronic irritant contact dermatitis (CICD) is not completely understood. To assess the association between FLG mutations and development of AD, ACD and CICD. This study assessed 241 patients with AD. AD developed during infancy in 85 patients, during childhood in 79 patients (32 early and 47 late) and during adulthood in 77 patients. We also included 100 patients with ACD and 44 with CICD, as well as 164 healthy controls. Four prevalent FLG loss-of-function mutations were genotyped (R501X, 2282del4, R2447X and S3247X). The 2282del4 mutation was significantly associated with a greater risk of AD in the entire group [odds ratio (OR) 4·33, 95% confidence interval (CI) 1·26-14·96]. However, the 2282del4 mutation was associated only with AD that developed during infancy or in early childhood (≤ 8 years: OR 20·91, 95% CI 2·73-159·9), not with AD development in late childhood or adulthood (> 8 or > 18 years), or ACD or CICD. Similar associations were also observed for the combined 2282del4 or R501X genotype. Carriers of FLG mutations also experienced a longer duration of AD and required hospitalization more often. FLG mutations are associated with only the early onset of AD, not late onset. Other factors should receive attention in patients with late-onset AD. © 2014 British Association of Dermatologists.

  18. PITX2 Loss-of-Function Mutation Contributes to Congenital Endocardial Cushion Defect and Axenfeld-Rieger Syndrome.

    Directory of Open Access Journals (Sweden)

    Cui-Mei Zhao

    Full Text Available Congenital heart disease (CHD, the most common type of birth defect, is still the leading non-infectious cause of infant morbidity and mortality in humans. Aggregating evidence demonstrates that genetic defects are involved in the pathogenesis of CHD. However, CHD is genetically heterogeneous and the genetic components underpinning CHD in an overwhelming majority of patients remain unclear. In the present study, the coding exons and flanking introns of the PITX2 gene, which encodes a paired-like homeodomain transcription factor 2essential for cardiovascular morphogenesis as well as maxillary facial development, was sequenced in 196 unrelated patients with CHD and subsequently in the mutation carrier's family members available. As a result, a novel heterozygous PITX2 mutation, p.Q102X for PITX2a, or p.Q148X for PITX2b, or p.Q155X for PITX2c, was identified in a family with endocardial cushion defect (ECD and Axenfeld-Rieger syndrome (ARS. Genetic analysis of the pedigree showed that the nonsense mutation co-segregated with ECD and ARS transmitted in an autosomal dominant pattern with complete penetrance. The mutation was absent in 800 control chromosomes from an ethnically matched population. Functional analysis by using a dual-luciferase reporter assay system revealed that the mutant PITX2 had no transcriptional activity and that the mutation eliminated synergistic transcriptional activation between PITX2 and NKX2.5, another transcription factor pivotal for cardiogenesis. To our knowledge, this is the first report on the association of PITX2 loss-of-function mutation with increased susceptibility to ECD and ARS. The findings provide novel insight into the molecular mechanisms underpinning ECD and ARS, suggesting the potential implications for the antenatal prophylaxis and personalized treatment of CHD and ARS.

  19. PITX2 Loss-of-Function Mutation Contributes to Congenital Endocardial Cushion Defect and Axenfeld-Rieger Syndrome.

    Science.gov (United States)

    Zhao, Cui-Mei; Peng, Lu-Ying; Li, Li; Liu, Xing-Yuan; Wang, Juan; Zhang, Xian-Ling; Yuan, Fang; Li, Ruo-Gu; Qiu, Xing-Biao; Yang, Yi-Qing

    2015-01-01

    Congenital heart disease (CHD), the most common type of birth defect, is still the leading non-infectious cause of infant morbidity and mortality in humans. Aggregating evidence demonstrates that genetic defects are involved in the pathogenesis of CHD. However, CHD is genetically heterogeneous and the genetic components underpinning CHD in an overwhelming majority of patients remain unclear. In the present study, the coding exons and flanking introns of the PITX2 gene, which encodes a paired-like homeodomain transcription factor 2essential for cardiovascular morphogenesis as well as maxillary facial development, was sequenced in 196 unrelated patients with CHD and subsequently in the mutation carrier's family members available. As a result, a novel heterozygous PITX2 mutation, p.Q102X for PITX2a, or p.Q148X for PITX2b, or p.Q155X for PITX2c, was identified in a family with endocardial cushion defect (ECD) and Axenfeld-Rieger syndrome (ARS). Genetic analysis of the pedigree showed that the nonsense mutation co-segregated with ECD and ARS transmitted in an autosomal dominant pattern with complete penetrance. The mutation was absent in 800 control chromosomes from an ethnically matched population. Functional analysis by using a dual-luciferase reporter assay system revealed that the mutant PITX2 had no transcriptional activity and that the mutation eliminated synergistic transcriptional activation between PITX2 and NKX2.5, another transcription factor pivotal for cardiogenesis. To our knowledge, this is the first report on the association of PITX2 loss-of-function mutation with increased susceptibility to ECD and ARS. The findings provide novel insight into the molecular mechanisms underpinning ECD and ARS, suggesting the potential implications for the antenatal prophylaxis and personalized treatment of CHD and ARS.

  20. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma.

    Directory of Open Access Journals (Sweden)

    Dirk Smith

    2017-03-01

    Full Text Available IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole-genome sequencing and imputation into the Icelandic population, we found a rare variant in IL33 (NM_001199640:exon7:c.487-1G>C (rs146597587-C, allele frequency = 0.65% that disrupts a canonical splice acceptor site before the last coding exon. It is also found at low frequency in European populations. rs146597587-C associates with lower eosinophil counts (β = -0.21 SD, P = 2.5×10-16, N = 103,104, and reduced risk of asthma in Europeans (OR = 0.47; 95%CI: 0.32, 0.70, P = 1.8×10-4, N cases = 6,465, N controls = 302,977. Heterozygotes have about 40% lower total IL33 mRNA expression than non-carriers and allele-specific analysis based on RNA sequencing and phased genotypes shows that only 20% of the total expression is from the mutated chromosome. In half of those transcripts the mutation causes retention of the last intron, predicted to result in a premature stop codon that leads to truncation of 66 amino acids. The truncated IL-33 has normal intracellular localization but neither binds IL-33R/ST2 nor activates ST2-expressing cells. Together these data demonstrate that rs146597587-C is a loss of function mutation and support the hypothesis that IL-33 haploinsufficiency protects against asthma.

  1. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma.

    Science.gov (United States)

    Smith, Dirk; Helgason, Hannes; Sulem, Patrick; Bjornsdottir, Unnur Steina; Lim, Ai Ching; Sveinbjornsson, Gardar; Hasegawa, Haruki; Brown, Michael; Ketchem, Randal R; Gavala, Monica; Garrett, Logan; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sigurdsson, Asgeir; Magnusson, Olafur T; Eyjolfsson, Gudmundur I; Olafsson, Isleifur; Onundarson, Pall Torfi; Sigurdardottir, Olof; Gislason, David; Gislason, Thorarinn; Ludviksson, Bjorn Runar; Ludviksdottir, Dora; Boezen, H Marike; Heinzmann, Andrea; Krueger, Marcus; Porsbjerg, Celeste; Ahluwalia, Tarunveer S; Waage, Johannes; Backer, Vibeke; Deichmann, Klaus A; Koppelman, Gerard H; Bønnelykke, Klaus; Bisgaard, Hans; Masson, Gisli; Thorsteinsdottir, Unnur; Gudbjartsson, Daniel F; Johnston, James A; Jonsdottir, Ingileif; Stefansson, Kari

    2017-03-01

    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole-genome sequencing and imputation into the Icelandic population, we found a rare variant in IL33 (NM_001199640:exon7:c.487-1G>C (rs146597587-C), allele frequency = 0.65%) that disrupts a canonical splice acceptor site before the last coding exon. It is also found at low frequency in European populations. rs146597587-C associates with lower eosinophil counts (β = -0.21 SD, P = 2.5×10-16, N = 103,104), and reduced risk of asthma in Europeans (OR = 0.47; 95%CI: 0.32, 0.70, P = 1.8×10-4, N cases = 6,465, N controls = 302,977). Heterozygotes have about 40% lower total IL33 mRNA expression than non-carriers and allele-specific analysis based on RNA sequencing and phased genotypes shows that only 20% of the total expression is from the mutated chromosome. In half of those transcripts the mutation causes retention of the last intron, predicted to result in a premature stop codon that leads to truncation of 66 amino acids. The truncated IL-33 has normal intracellular localization but neither binds IL-33R/ST2 nor activates ST2-expressing cells. Together these data demonstrate that rs146597587-C is a loss of function mutation and support the hypothesis that IL-33 haploinsufficiency protects against asthma.

  2. Sinorhizobium meliloti 1021 loss-of-function deletion mutation in chvI and its phenotypic characteristics.

    Science.gov (United States)

    Wang, Chunxia; Kemp, Jocelyn; Da Fonseca, Isabel O; Equi, Raymie C; Sheng, Xiaoyan; Charles, Trevor C; Sobral, Bruno W S

    2010-02-01

    Bacterial two-component regulatory systems (TCS) are common components of complex regulatory networks and cascades. In Sinorhizobium meliloti, the TCS ExoS/ChvI controls exopolysaccharide succinoglycan production and flagellum biosynthesis. Although this system plays a crucial role in establishing the symbiosis between S. meliloti and its host plant, it is not well characterized. Attempts to generate complete loss-of-function mutations in either exoS or chvI in S. meliloti have been unsuccessful; thus, it was previously suggested that exoS or chvI are essential genes for bacterial cell growth. We constructed a chvI mutant by completely deleting the open reading frame encoding this gene. The mutant strain failed to grow on complex medium, exhibited lower tolerance to acidic condition, produced significantly less poly-3-hydroxybutyrate than the wild type, was hypermotile, and exhibited an altered lipopolysaccharide profile. In addition, this mutant was defective in symbiosis with Medicago truncatula and M. sativa (alfalfa), although it induced root hair deformation as efficiently as the wild type. Together, our results demonstrate that ChvI is intimately involved in regulatory networks involving the cell envelope and metabolism; however, its precise role within the regulatory network remains to be determined.

  3. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma

    DEFF Research Database (Denmark)

    Smith, Dirk; Helgason, Hannes; Sulem, Patrick

    2017-01-01

    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole......-C associates with lower eosinophil counts (β = -0.21 SD, P = 2.5×10-16, N = 103,104), and reduced risk of asthma in Europeans (OR = 0.47; 95%CI: 0.32, 0.70, P = 1.8×10-4, N cases = 6,465, N controls = 302,977). Heterozygotes have about 40% lower total IL33 mRNA expression than non...... amino acids. The truncated IL-33 has normal intracellular localization but neither binds IL-33R/ST2 nor activates ST2-expressing cells. Together these data demonstrate that rs146597587-C is a loss of function mutation and support the hypothesis that IL-33 haploinsufficiency protects against asthma....

  4. Adverse events in a newborn on valproate therapy due to loss-of-function mutations in CYP2C9

    Directory of Open Access Journals (Sweden)

    Andrea Nagy

    2015-01-01

    Full Text Available An increased risk of valproate-induced toxicity has been reported in children, particularly in those younger than 2 years of age. Significant variations in valproate pharmacokinetics and shifts in the metabolic pathways towards CYP2C9-dependent metabolism seem to play some role in the age-related differences in the incidence of adverse events. We present the case of a premature patient with moderate hemorrhage in the subependymal region (grade II — intraventricular hemorrhage without ventricular dilatation, several myoclonic episodes in her right upper arm (series of jerks lasting milliseconds, and epileptiform abnormalities on the EEG (localized spike-and-wave in the left frontal region with preserved background activity who was treated with valproate. Serious side effects, consisting of bone marrow depression, hyperammonemia, and serum alkaline phosphatase elevation, were observed seventeen days after the beginning of valproate therapy. The toxic symptoms were likely the consequence of a reduced ability to metabolize valproate. The patient was demonstrated to carry two loss-of-function mutations in CYP2C9 (CYP2C9*3/*3 resulting in exaggerated blood concentrations of valproate. The present case highlights the importance of assaying inborn errors in CYP2C9 gene in pediatric patients to avoid valproate-evoked serious side effects.

  5. Exposure to phenols, parabens and UV filters: Associations with loss-of-function mutations in the filaggrin gene in men from the general population.

    Science.gov (United States)

    Joensen, Ulla N; Jørgensen, Niels; Thyssen, Jacob P; Petersen, Jørgen Holm; Szecsi, Pal B; Stender, Steen; Andersson, Anne-Maria; Skakkebæk, Niels E; Frederiksen, Hanne

    2017-08-01

    Filaggrin is an epidermal protein that is important for normal skin barrier functions. Up to 10% of Europeans and Asians carry filaggrin gene (FLG) loss-of function mutations that appear to facilitate trans-epidermal penetration of certain chemicals. We previously showed that mutation carriers have higher internal exposure to certain phthalates, compared to controls, and hypothesized that they could have increased trans-epidermal penetration of other chemicals. We investigated exposure to non-persistent chemicals in young Danish men with and without FLG mutations. Concentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation status and chemical concentrations in urine. FLG mutation carriers had 80% (13-180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13-219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although differences were only statistically significant for MeP and n-PrP. Combined statistical analysis of concentrations of all the 18 compounds that were detectable in >10% of subjects, suggested that concentrations were generally higher in mutation carriers (p=0.03). FLG loss-of-function mutation carriers have a higher internal exposure to some non-persistent chemicals, independently of atopic dermatitis. This may be due to increased trans-epidermal absorption and/or higher exposure, and mutation carriers may constitute a group susceptible to increased absorption of chemicals and topical medication. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. WAC loss-of-function mutations cause a recognisable syndrome characterised by dysmorphic features, developmental delay and hypotonia and recapitulate 10p11.23 microdeletion syndrome.

    Science.gov (United States)

    DeSanto, Cori; D'Aco, Kristin; Araujo, Gabriel C; Shannon, Nora; Vernon, Hilary; Rahrig, April; Monaghan, Kristin G; Niu, Zhiyv; Vitazka, Patrik; Dodd, Jonathan; Tang, Sha; Manwaring, Linda; Martir-Negron, Arelis; Schnur, Rhonda E; Juusola, Jane; Schroeder, Audrey; Pan, Vivian; Helbig, Katherine L; Friedman, Bethany; Shinawi, Marwan

    2015-11-01

    Rare de novo mutations have been implicated as a significant cause of idiopathic intellectual disability. Large deletions encompassing 10p11.23 have been implicated in developmental delay, behavioural abnormalities and dysmorphic features, but the genotype-phenotype correlation was not delineated. Mutations in WAC have been recently reported in large screening cohorts of patients with intellectual disability or autism, but no full phenotypic characterisation was described. Clinical and molecular characterisation of six patients with loss-of-function WAC mutations identified by whole exome sequencing was performed. Clinical data were obtained by retrospective chart review, parental interviews, direct patient interaction and formal neuropsychological evaluation. Five heterozygous de novo WAC mutations were identified in six patients. Three of the mutations were nonsense, and two were frameshift; all are predicted to cause loss of function either through nonsense-mediated mRNA decay or protein truncation. Clinical findings included developmental delay (6/6), hypotonia (6/6), behavioural problems (5/6), eye abnormalities (5/6), constipation (5/6), feeding difficulties (4/6), seizures (2/6) and sleep problems (2/6). All patients exhibited common dysmorphic features, including broad/prominent forehead, synophrys and/or bushy eyebrows, depressed nasal bridge and bulbous nasal tip. Posteriorly rotated ears, hirsutism, deep-set eyes, thin upper lip, inverted nipples, hearing loss and branchial cleft anomalies were also noted. Our case series show that loss-of-function mutations in WAC cause a recognisable genetic syndrome characterised by a neurocognitive phenotype and facial dysmorphism. Our data highly suggest that WAC haploinsufficiency is responsible for most of the phenotypic features associated with deletions encompassing 10p11.23. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Compound Heterozygosity of Low-Frequency Promoter Deletions and Rare Loss-of-Function Mutations in TXNL4A Causes Burn-McKeown Syndrome

    Science.gov (United States)

    Wieczorek, Dagmar; Newman, William G.; Wieland, Thomas; Berulava, Tea; Kaffe, Maria; Falkenstein, Daniela; Beetz, Christian; Graf, Elisabeth; Schwarzmayr, Thomas; Douzgou, Sofia; Clayton-Smith, Jill; Daly, Sarah B.; Williams, Simon G.; Bhaskar, Sanjeev S.; Urquhart, Jill E.; Anderson, Beverley; O’Sullivan, James; Boute, Odile; Gundlach, Jasmin; Czeschik, Johanna Christina; van Essen, Anthonie J.; Hazan, Filiz; Park, Sarah; Hing, Anne; Kuechler, Alma; Lohmann, Dietmar R.; Ludwig, Kerstin U.; Mangold, Elisabeth; Steenpaß, Laura; Zeschnigk, Michael; Lemke, Johannes R.; Lourenco, Charles Marques; Hehr, Ute; Prott, Eva-Christina; Waldenberger, Melanie; Böhmer, Anne C.; Horsthemke, Bernhard; O’Keefe, Raymond T.; Meitinger, Thomas; Burn, John; Lüdecke, Hermann-Josef; Strom, Tim M.

    2014-01-01

    Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The U5 spliceosomal complex of eight highly conserved proteins is critical for pre-mRNA splicing. We identified biallelic mutations in TXNL4A, a member of this complex, in individuals with Burn-McKeown syndrome (BMKS). This rare condition is characterized by bilateral choanal atresia, hearing loss, cleft lip and/or palate, and other craniofacial dysmorphisms. Mutations were found in 9 of 11 affected families. In 8 families, affected individuals carried a rare loss-of-function mutation (nonsense, frameshift, or microdeletion) on one allele and a low-frequency 34 bp deletion (allele frequency 0.76%) in the core promoter region on the other allele. In a single highly consanguineous family, formerly diagnosed as oculo-oto-facial dysplasia, the four affected individuals were homozygous for a 34 bp promoter deletion, which differed from the promoter deletion in the other families. Reporter gene and in vivo assays showed that the promoter deletions led to reduced expression of TXNL4A. Depletion of TXNL4A (Dib1) in yeast demonstrated reduced assembly of the tri-snRNP complex. Our results indicate that BMKS is an autosomal-recessive condition, which is frequently caused by compound heterozygosity of low-frequency promoter deletions in combination with very rare loss-of-function mutations. PMID:25434003

  8. De novo gain-of-function and loss-of-function mutations of SCN8A in patients with intellectual disabilities and epilepsy.

    Science.gov (United States)

    Blanchard, Maxime G; Willemsen, Marjolein H; Walker, Jaclyn B; Dib-Hajj, Sulayman D; Waxman, Stephen G; Jongmans, Marjolijn C J; Kleefstra, Tjitske; van de Warrenburg, Bart P; Praamstra, Peter; Nicolai, Joost; Yntema, Helger G; Bindels, René J M; Meisler, Miriam H; Kamsteeg, Erik-Jan

    2015-05-01

    Mutations of SCN8A encoding the neuronal voltage-gated sodium channel NaV1.6 are associated with early-infantile epileptic encephalopathy type 13 (EIEE13) and intellectual disability. Using clinical exome sequencing, we have detected three novel de novo SCN8A mutations in patients with intellectual disabilities, and variable clinical features including seizures in two patients. To determine the causality of these SCN8A mutations in the disease of those three patients, we aimed to study the (dys)function of the mutant sodium channels. The functional consequences of the three SCN8A mutations were assessed using electrophysiological analyses in transfected cells. Genotype-phenotype correlations of these and other cases were related to the functional analyses. The first mutant displayed a 10 mV hyperpolarising shift in voltage dependence of activation (gain of function), the second did not form functional channels (loss of function), while the third mutation was functionally indistinguishable from the wildtype channel. Comparison of the clinical features of these patients with those in the literature suggests that gain-of-function mutations are associated with severe EIEE, while heterozygous loss-of-function mutations cause intellectual disability with or without seizures. These data demonstrate that functional analysis of missense mutations detected by clinical exome sequencing, both inherited and de novo, is valuable for clinical interpretation in the age of massive parallel sequencing. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Loss of function JAK1 mutations occur at high frequency in cancers with microsatellite instability and are suggestive of immune evasion.

    Science.gov (United States)

    Albacker, Lee A; Wu, Jeremy; Smith, Peter; Warmuth, Markus; Stephens, Philip J; Zhu, Ping; Yu, Lihua; Chmielecki, Juliann

    2017-01-01

    Immune evasion is a well-recognized hallmark of cancer and recent studies with immunotherapy agents have suggested that tumors with increased numbers of neoantigens elicit greater immune responses. We hypothesized that the immune system presents a common selective pressure on high mutation burden tumors and therefore immune evasion mutations would be enriched in high mutation burden tumors. The JAK family of kinases is required for the signaling of a host of immune modulators in tumor, stromal, and immune cells. Therefore, we analyzed alterations in this family for the hypothesized signature of an immune evasion mutation. Here, we searched a database of 61,704 unique solid tumors for alterations in the JAK family kinases (JAK1/2/3, TYK2). We used The Cancer Genome Atlas and Cancer Cell Line Encyclopedia data to confirm and extend our findings by analyzing gene expression patterns. Recurrent frameshift mutations in JAK1 were associated with high mutation burden and microsatellite instability. These mutations occurred in multiple tumor types including endometrial, colorectal, stomach, and prostate carcinomas. Analyzing gene expression signatures in endometrial and stomach adenocarcinomas revealed that tumors with a JAK1 frameshift exhibited reduced expression of interferon response signatures and multiple anti-tumor immune signatures. Importantly, endometrial cancer cell lines exhibited similar gene expression changes that were expected to be tumor cell intrinsic (e.g. interferon response) but not those expected to be tumor cell extrinsic (e.g. NK cells). From these data, we derive two primary conclusions: 1) JAK1 frameshifts are loss of function alterations that represent a potential pan-cancer adaptation to immune responses against tumors with microsatellite instability; 2) The mechanism by which JAK1 loss of function contributes to tumor immune evasion is likely associated with loss of the JAK1-mediated interferon response.

  10. Gene-environment interaction in the onset of eczema in infancy: filaggrin loss-of-function mutations enhanced by neonatal cat exposure.

    Directory of Open Access Journals (Sweden)

    Hans Bisgaard

    2008-06-01

    Full Text Available BACKGROUND: Loss-of-function variants in the gene encoding filaggrin (FLG are major determinants of eczema. We hypothesized that weakening of the physical barrier in FLG-deficient individuals may potentiate the effect of environmental exposures. Therefore, we investigated whether there is an interaction between FLG loss-of-function mutations with environmental exposures (pets and dust mites in relation to the development of eczema. METHODS AND FINDINGS: We used data obtained in early life in a high-risk birth cohort in Denmark and replicated the findings in an unselected birth cohort in the United Kingdom. Primary outcome was age of onset of eczema; environmental exposures included pet ownership and mite and pet allergen levels. In Copenhagen (n = 379, FLG mutation increased the risk of eczema during the first year of life (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.27-4.00, p = 0.005, with a further increase in risk related to cat exposure at birth amongst children with FLG mutation (HR 11.11, 95% CI 3.79-32.60, p < 0.0001; dog exposure was moderately protective (HR 0.49, 95% CI 0.24-1.01, p = 0.05, but not related to FLG genotype. In Manchester (n = 503 an independent and significant association of the development of eczema by age 12 mo with FLG genotype was confirmed (HR 1.95, 95% CI 1.13-3.36, p = 0.02. In addition, the risk increased because of the interaction of cat ownership at birth and FLG genotype (HR 3.82, 95% CI 1.35-10.81, p = 0.01, with no significant effect of the interaction with dog ownership (HR 0.59, 95% CI 0.16-2.20, p = 0.43. Mite-allergen had no effects in either cohort. The observed effects were independent of sensitisation. CONCLUSIONS: We have demonstrated a significant interaction between FLG loss-of-function main mutations (501x and 2282del4 and cat ownership at birth on the development of early-life eczema in two independent birth cohorts. Our data suggest that cat but not dog ownership substantially

  11. GATAD2B loss-of-function mutations cause a recognisable syndrome with intellectual disability and are associated with learning deficits and synaptic undergrowth in Drosophila.

    Science.gov (United States)

    Willemsen, Marjolein H; Nijhof, Bonnie; Fenckova, Michaela; Nillesen, Willy M; Bongers, Ernie M H F; Castells-Nobau, Anna; Asztalos, Lenke; Viragh, Erika; van Bon, Bregje W M; Tezel, Emre; Veltman, Joris A; Brunner, Han G; de Vries, Bert B A; de Ligt, Joep; Yntema, Helger G; van Bokhoven, Hans; Isidor, Bertrand; Le Caignec, Cédric; Lorino, Elsa; Asztalos, Zoltan; Koolen, David A; Vissers, Lisenka E L M; Schenck, Annette; Kleefstra, Tjitske

    2013-08-01

    GATA zinc finger domain containing 2B (GATAD2B) encodes a subunit of the MeCP1-Mi-2/nucleosome remodelling and deacetylase complex involved in chromatin modification and regulation of transcription. We recently identified two de novo loss-of-function mutations in GATAD2B by whole exome sequencing in two unrelated individuals with severe intellectual disability. To identify additional individuals with GATAD2B aberrations, we searched for microdeletions overlapping with GATAD2B in inhouse and international databases, and performed targeted Sanger sequencing of the GATAD2B locus in a selected cohort of 80 individuals based on an overlap with the clinical features in the two index cases. To address whether GATAD2B is required directly in neurones for cognition and neuronal development, we investigated the role of Drosophila GATAD2B orthologue simjang (simj) in learning and synaptic connectivity. We identified a third individual with a 240 kb microdeletion encompassing GATAD2B and a fourth unrelated individual with GATAD2B loss-of-function mutation. Detailed clinical description showed that all four individuals with a GATAD2B aberration had a distinctive phenotype with childhood hypotonia, severe intellectual disability, limited speech, tubular shaped nose with broad nasal tip, short philtrum, sparse hair and strabismus. Neuronal knockdown of Drosophila GATAD2B orthologue, simj, resulted in impaired learning and altered synapse morphology. We hereby define a novel clinically recognisable intellectual disability syndrome caused by loss-of-function of GATAD2B. Our results in Drosophila suggest that GATAD2B is required directly in neurones for normal cognitive performance and synapse development.

  12. Loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen Erysiphe cichoracearum.

    Science.gov (United States)

    Ramonell, Katrina; Berrocal-Lobo, Marta; Koh, Serry; Wan, Jinrong; Edwards, Herb; Stacey, Gary; Somerville, Shauna

    2005-06-01

    Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. The expression patterns elicited by the chito-octamer and hydrolyzed chitin were similar. Microarray expression profiles for several genes were verified via northern analysis or quantitative reverse transcription-PCR. We characterized T-DNA insertion mutants for nine chito-oligomer responsive genes. Three of the mutants were more susceptible to the fungal pathogen, powdery mildew, than wild type as measured by conidiophore production. These three mutants included mutants of genes for two disease resistance-like proteins and a putative E3 ligase. The isolation of loss-of-function mutants with enhanced disease susceptibility provides direct evidence that the chito-octamer is an important oligosaccharide elicitor of plant defenses. Also, this study demonstrates the value of microarray data for identifying new components of uncharacterized signaling pathways.

  13. SDHA loss of function mutations in a subset of young adult wild-type gastrointestinal stromal tumors

    International Nuclear Information System (INIS)

    Italiano, Antoine; Chen, Chun-Liang; Sung, Yun-Shao; Singer, Samuel; DeMatteo, Ronald P; LaQuaglia, Michael P; Besmer, Peter; Socci, Nicholas; Antonescu, Cristina R

    2012-01-01

    A subset of KIT/PDGFRA wild-type gastrointestinal stromal tumors (WT GIST) have been associated with alteration of the succinate dehydrogenase (SDH) complex II function. A recent report identified four non-syndromic, KIT/PDGFRA WT GIST harboring compound heterozygous or homozygous mutations in SDHA encoding the main subunit of the SDH complex II. Next generation sequencing was applied on five pediatric and one young adult WT GIST, by whole exome capture and SOLiD 3-plus system sequencing. The putative mutations were first confirmed by Sanger sequencing and then screened on a larger panel of 11 pediatric and young adult WT GIST, including 5 in the context of Carney triad. A germline p.Arg31X nonsense SDHA mutation was identified in one of the six cases tested by SOLiD platform. An additional p.D38V missense mutation in SDHA exon 2 was identified by Sanger sequencing in the extended KIT/PDGFRA WT GIST patients cohort. Western blotting showed loss of SDHA expression in the two cases harboring SDHA mutations, while expression being retained in the other WT GIST tumors. Results were further confirmed by immunohistochemistry for both SDHA and SDHB, which showed a concurrent loss of expression of both proteins in SDHA-mutant lesions, while the remaining WT tumors showed only loss of SDHB expression. Germline and/or somatic aberrations of SDHA occur in a small subset of KIT/PDGFRA WT GISTs, outside the Carney’s triad and are associated with loss of both SDHA and SDHB protein expression. Mutations of the SDH complex II are more particularly associated with KIT/PDGFRA WT GIST occurring in young adults. Although pediatric GIST consistently display alterations of SDHB protein expression, further molecular studies are needed to identify the crucial genes involved in their tumorigenesis

  14. Reciprocal mouse and human limb phenotypes caused by gain- and loss-of-function mutations affecting Lmbr1.

    OpenAIRE

    Clark, R M; Marker, P C; Roessler, E; Dutra, A; Schimenti, J C; Muenke, M; Kingsley, D M

    2001-01-01

    The major locus for dominant preaxial polydactyly in humans has been mapped to 7q36. In mice the dominant Hemimelic extra toes (Hx) and Hammertoe (Hm) mutations map to a homologous chromosomal region and cause similar limb defects. The Lmbr1 gene is entirely within the small critical intervals recently defined for both the mouse and human mutations and is misexpressed at the exact time that the mouse Hx phenotype becomes apparent during limb development. This result suggests that Lmbr1 may un...

  15. Unusual long survival despite severe lung disease of a child with biallelic loss of function mutations in ABCA-3

    Directory of Open Access Journals (Sweden)

    P. El Boustany

    Full Text Available Homozygous or compound heterozygous for frameshift or nonsense mutations in the ATP–binding cassette transporter A3 (ABCA3 is associated with neonatal respiratory failure and death within the first year of life without lung transplantation. We report the case of a newborn baby girl who developed severe respiratory distress soon after birth. She was diagnosed with compound heterozygous frameshift mutation of the ABCA3 gene. Despite extensive treatment (intravenous corticosteroids pulse therapy, oral corticosteroids, azithromycin, and hydroxychloroquine, she developed chronic respiratory failure. As the parents refused cardio-pulmonary transplantation and couldn't resolve to an accompaniment of end of life, a tracheostomy was performed resulting in continuous mechanical ventilation. A neurodevelopmental delay and an overall muscular dystrophy were noted. At the age of 5 years, after 2 episodes of pneumothorax, the patient died from severe respiratory failure. To our knowledge, this was the first case of a child with compound heterozygous frameshift mutation who posed such an ethical dilemma with a patient surviving till the age of five years. Keywords: ABCA3 deficiency, Compound heterozygous frameshift mutation, Neonatal respiratory failure, Tracheostomy, Mechanical ventilation, Ethical dilemma

  16. Loss-of-Function Mutations in APOC3 and Risk of Ischemic Vascular Disease

    DEFF Research Database (Denmark)

    Jørgensen, Anders Berg; Frikke-Schmidt, Ruth; Nordestgaard, Børge G

    2014-01-01

    BACKGROUND: High plasma levels of nonfasting triglycerides are associated with an increased risk of ischemic cardiovascular disease. Whether lifelong low levels of nonfasting triglycerides owing to mutations in the gene encoding apolipoprotein C3 (APOC3) are associated with a reduced risk of isch...

  17. Carriers of loss-of-function mutations in EXT display impaired pancreatic beta-cell reserve due to smaller pancreas volume.

    Directory of Open Access Journals (Sweden)

    Sophie J Bernelot Moens

    Full Text Available Exotosin (EXT proteins are involved in the chain elongation step of heparan sulfate (HS biosynthesis, which is intricately involved in organ development. Loss of function mutations (LOF in EXT1 and EXT2 result in hereditary exostoses (HME. Interestingly, HS plays a role in pancreas development and beta-cell function, and genetic variations in EXT2 are associated with an increased risk for type 2 diabetes mellitus. We hypothesized that loss of function of EXT1 or EXT2 in subjects with hereditary multiple exostoses (HME affects pancreatic insulin secretion capacity and development. We performed an oral glucose tolerance test (OGTT followed by hyperglycemic clamps to investigate first-phase glucose-stimulated insulin secretion (GSIS in HME patients and age and gender matched non-affected relatives. Pancreas volume was assessed with magnetic resonance imaging (MRI. OGTT did not reveal significant differences in glucose disposal, but there was a markedly lower GSIS in HME subjects during hyperglycemic clamp (iAUC HME: 0.72 [0.46-1.16] vs. controls 1.53 [0.69-3.36] nmol·l-1·min-1, p<0.05. Maximal insulin response following arginine challenge was also significantly attenuated (iAUC HME: 7.14 [4.22-10.5] vs. controls 10.2 [7.91-12.70] nmol·l-1·min-1 p<0.05, indicative of an impaired beta-cell reserve. MRI revealed a significantly smaller pancreatic volume in HME subjects (HME: 72.0±15.8 vs. controls 96.5±26.0 cm3 p = 0.04. In conclusion, loss of function of EXT proteins may affect beta-cell mass and insulin secretion capacity in humans, and render subjects at a higher risk of developing type 2 diabetes when exposed to environmental risk factors.

  18. Heterozygosity for ARID2 loss-of-function mutations in individuals with a Coffin-Siris syndrome-like phenotype.

    Science.gov (United States)

    Bramswig, Nuria C; Caluseriu, O; Lüdecke, H-J; Bolduc, F V; Noel, N C L; Wieland, T; Surowy, H M; Christen, H-J; Engels, H; Strom, T M; Wieczorek, D

    2017-03-01

    Chromatin remodeling is a complex process shaping the nucleosome landscape, thereby regulating the accessibility of transcription factors to regulatory regions of target genes and ultimately managing gene expression. The SWI/SNF (switch/sucrose nonfermentable) complex remodels the nucleosome landscape in an ATP-dependent manner and is divided into the two major subclasses Brahma-associated factor (BAF) and Polybromo Brahma-associated factor (PBAF) complex. Somatic mutations in subunits of the SWI/SNF complex have been associated with different cancers, while germline mutations have been associated with autism spectrum disorder and the neurodevelopmental disorders Coffin-Siris (CSS) and Nicolaides-Baraitser syndromes (NCBRS). CSS is characterized by intellectual disability (ID), coarsening of the face and hypoplasia or absence of the fifth finger- and/or toenails. So far, variants in five of the SWI/SNF subunit-encoding genes ARID1B, SMARCA4, SMARCB1, ARID1A, and SMARCE1 as well as variants in the transcription factor-encoding gene SOX11 have been identified in CSS-affected individuals. ARID2 is a member of the PBAF subcomplex, which until recently had not been linked to any neurodevelopmental phenotypes. In 2015, mutations in the ARID2 gene were associated with intellectual disability. In this study, we report on two individuals with private de novo ARID2 frameshift mutations. Both individuals present with a CSS-like phenotype including ID, coarsening of facial features, other recognizable facial dysmorphisms and hypoplasia of the fifth toenails. Hence, this study identifies mutations in the ARID2 gene as a novel and rare cause for a CSS-like phenotype and enlarges the list of CSS-like genes.

  19. Loss-of-function HDAC8 mutations cause a phenotypic spectrum of Cornelia de Lange syndrome-like features, ocular hypertelorism, large fontanelle and X-linked inheritance

    Science.gov (United States)

    Kaiser, Frank J.; Ansari, Morad; Braunholz, Diana; Concepción Gil-Rodríguez, María; Decroos, Christophe; Wilde, Jonathan J.; Fincher, Christopher T.; Kaur, Maninder; Bando, Masashige; Amor, David J.; Atwal, Paldeep S.; Bahlo, Melanie; Bowman, Christine M.; Bradley, Jacquelyn J.; Brunner, Han G.; Clark, Dinah; Del Campo, Miguel; Di Donato, Nataliya; Diakumis, Peter; Dubbs, Holly; Dyment, David A.; Eckhold, Juliane; Ernst, Sarah; Ferreira, Jose C.; Francey, Lauren J.; Gehlken, Ulrike; Guillén-Navarro, Encarna; Gyftodimou, Yolanda; Hall, Bryan D.; Hennekam, Raoul; Hudgins, Louanne; Hullings, Melanie; Hunter, Jennifer M.; Yntema, Helger; Innes, A. Micheil; Kline, Antonie D.; Krumina, Zita; Lee, Hane; Leppig, Kathleen; Lynch, Sally Ann; Mallozzi, Mark B.; Mannini, Linda; Mckee, Shane; Mehta, Sarju G.; Micule, Ieva; Mohammed, Shehla; Moran, Ellen; Mortier, Geert R.; Moser, Joe-Ann S.; Noon, Sarah E.; Nozaki, Naohito; Nunes, Luis; Pappas, John G.; Penney, Lynette S.; Pérez-Aytés, Antonio; Petersen, Michael B.; Puisac, Beatriz; Revencu, Nicole; Roeder, Elizabeth; Saitta, Sulagna; Scheuerle, Angela E.; Schindeler, Karen L.; Siu, Victoria M.; Stark, Zornitza; Strom, Samuel P.; Thiese, Heidi; Vater, Inga; Willems, Patrick; Williamson, Kathleen; Wilson, Louise C.; Hakonarson, Hakon; Quintero-Rivera, Fabiola; Wierzba, Jolanta; Musio, Antonio; Gillessen-Kaesbach, Gabriele; Ramos, Feliciano J.; Jackson, Laird G.; Shirahige, Katsuhiko; Pié, Juan; Christianson, David W.; Krantz, Ian D.; Fitzpatrick, David R.; Deardorff, Matthew A.

    2014-01-01

    Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80% of cases with typical facies. Mutations in the core cohesin complex proteins, encoded by the SMC1A, SMC3 and RAD21 genes, together account for ∼5% of subjects, often with atypical CdLS features. Recently, we identified mutations in the X-linked gene HDAC8 as the cause of a small number of CdLS cases. Here, we report a cohort of 38 individuals with an emerging spectrum of features caused by HDAC8 mutations. For several individuals, the diagnosis of CdLS was not considered prior to genomic testing. Most mutations identified are missense and de novo. Many cases are heterozygous females, each with marked skewing of X-inactivation in peripheral blood DNA. We also identified eight hemizygous males who are more severely affected. The craniofacial appearance caused by HDAC8 mutations overlaps that of typical CdLS but often displays delayed anterior fontanelle closure, ocular hypertelorism, hooding of the eyelids, a broader nose and dental anomalies, which may be useful discriminating features. HDAC8 encodes the lysine deacetylase for the cohesin subunit SMC3 and analysis of the functional consequences of the missense mutations indicates that all cause a loss of enzymatic function. These data demonstrate that loss-of-function mutations in HDAC8 cause a range of overlapping human developmental phenotypes, including a phenotypically distinct subgroup of CdLS. PMID:24403048

  20. Neurodegenerative disease mutations in TREM2 reveal a functional surface and distinct loss-of-function mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Kober, Daniel L.; Alexander-Brett, Jennifer M.; Karch, Celeste M.; Cruchaga, Carlos; Colonna, Marco; Holtzman, Michael J.; Brett, Thomas J. (WU-MED)

    2016-12-20

    Genetic variations in the myeloid immune receptor TREM2 are linked to several neurodegenerative diseases. To determine how TREM2 variants contribute to these diseases, we performed structural and functional studies of wild-type and variant proteins. Our 3.1 Å TREM2 crystal structure revealed that mutations found in Nasu-Hakola disease are buried whereas Alzheimer’s disease risk variants are found on the surface, suggesting that these mutations have distinct effects on TREM2 function. Biophysical and cellular methods indicate that Nasu-Hakola mutations impact protein stability and decrease folded TREM2 surface expression, whereas Alzheimer’s risk variants impact binding to a TREM2 ligand. Additionally, the Alzheimer’s risk variants appear to epitope map a functional surface on TREM2 that is unique within the larger TREM family. These findings provide a guide to structural and functional differences among genetic variants of TREM2, indicating that therapies targeting the TREM2 pathway should be tailored to these genetic and functional differences with patient-specific medicine approaches for neurodegenerative disorders.

  1. Analyses of loss-of-function mutations of the MITF gene suggest that haploinsufficiency is a cause of Waardenburg syndrome type 2A

    Energy Technology Data Exchange (ETDEWEB)

    Nobukuni, Yoshitaka; Watanabe, A.; Takeda, Kazushisa; Skarka, Hana; Tachibana, Masayoshi [National Inst. of Health, Bethesda, MD (United States)

    1996-07-01

    Waardenburg syndrome type 2 (WS2) is a dominantly inherited disorder characterized by a pigmentation anomaly and hearing impairment due to lack of melanocyte. Previous work has linked a subset of families with WS2 (WS2A) to the MITF gene that encodes a transcription factor with a basic-helix-loop-helix-leucine zipper (bHLH-Zip) motif and that is involved in melanocyte differentiation. Several splice-site and missense mutations have been reported in individuals affected with WS2A. In this report, we have identified two novel point mutations in the MITF gene in affected individuals from two different families with WS2A. The two mutations (C760{r_arrow}T and C895{r_arrow}T) create stop codons in exons 7 and 8, respectively. Corresponding mutant alleles predict the truncated proteins lacking HLH-Zip or Zip structure. To understand how these mutations cause WS2 in heterozygotes, we generated mutant MITF cDNAs and used them for DNA-binding and luciferase reporter assays. The mutated MITF proteins lose the DNA-binding activity and fail to transactivate the promoter of tyrosinase, a melanocyte-specific enzyme. However, these mutated proteins do not appear to interfere with the activity of wild-type MITF protein in these assays, indicating that they do not show a dominant-negative effect. These findings suggest that the phenotypes of the two families with WS2A in the present study are caused by loss-of-function mutations in one of the two alleles of the MITF gene, resulting in haploinsufficiency of the MITF protein, the protein necessary for normal development of melanocytes. 37 refs., 4 figs.

  2. Pharmacological characterization of loss of function mutations of the human melanocortin 1 receptor that are associated with red hair.

    Science.gov (United States)

    Ringholm, Aneta; Klovins, Janis; Rudzish, Richard; Phillips, Sion; Rees, Jonathan L; Schiöth, Helgi B

    2004-11-01

    Variation in skin color is the major host risk factor for melanoma and other forms of skin cancer. Individuals with red hair show an increased ratio of phaeomelanin to eumelanin in both hair and skin. This ratio is regulated by the melanocortin (MC) 1 receptor. There are several common point mutations in the human MC1 receptor that are overrepresented in North European red-heads, and in individuals with pale skin. In order to determine the functional significance of these mutations, we expressed the Asp84Glu, Val92Met, Arg163Gln, and Asp294His variants of the human MC1 receptors in eukaryotic cells and determined their ability to bind alpha-melanocyte stimulating hormone (MSH) peptides and increase intracellular cAMP. The mutants Asp84Glu and Asp294His showed a much lower response to alpha-MSH in cAMP and a slightly impaired ability to bind alpha-MSH, and the Val92Met mutant bound alpha-MSH with 100-fold lower affinity as compared with the wild-type. The Arg163Gln variant, widely found in some Asian populations, reached normal level of cAMP response but had just slightly lower potency for alpha-MSH in binding and second messenger studies. The results provide important pharmacological characterization of common MC1 receptor variants in various world populations.

  3. Loss of function mutations in PTPN6 promote STAT3 deregulation via JAK3 kinase in diffuse large B-cell lymphoma

    Science.gov (United States)

    Demosthenous, Christos; Han, Jing Jing; Hu, Guangzhen; Stenson, Mary; Gupta, Mamta

    2015-01-01

    PTPN6 (SHP1) is a tyrosine phosphatase that negatively controls the activity of multiple signaling pathways including STAT signaling, however role of mutated PTPN6 is not much known. Here we investigated whether PTPN6 might also be a potential target for diffuse large B cell lymphoma (DLBCL) and performed Sanger sequencing of the PTPN6 gene. We have identified missense mutations within PTPN6 (N225K and A550V) in 5% (2/38) of DLBCL tumors. Site directed mutagenesis was performed to mutate wild type (WT) PTPN6 and stable cell lines were generated by lentiviral transduction of PTPN6WT, PTPN6N225K and PTPN6A550V constructs, and effects of WT or mutated PTPN6 on STAT3 signaling were analyzed. WT PTPN6 dephosphorylated STAT3, but had no effect on STAT1, STAT5 or STAT6 phosphorylation. Both PTPN6 mutants were unable to inhibit constitutive, as well as cytokines induced STAT3 activation. Both PTPN6 mutants also demonstrated reduced tyrosine phosphatase activity and exhibited enhanced STAT3 transactivation activity. Intriguingly, a lack of direct binding between STAT3 and WT or mutated PTPN6 was observed. However, compared to WT PTPN6, cells expressing PTPN6 mutants exhibited increased binding between JAK3 and PTPN6 suggesting a more dynamic interaction of PTPN6 with upstream regulators of STAT3. Consistent with this notion, both the mutants demonstrated increased resistance to JAK3 inhibitor, WHIP-154 relative to WT PTPN6. Overall, this is the first study, which demonstrates that N225K and A550V PTPN6 mutations cause loss-of-function leading to JAK3 mediated deregulation of STAT3 pathway and uncovers a mechanism that tumor cells can use to control PTPN6 substrate specificity. PMID:26565811

  4. Loss-of-function mutation inMirta22/Emc10rescues specific schizophrenia-related phenotypes in a mouse model of the 22q11.2 deletion.

    Science.gov (United States)

    Diamantopoulou, Anastasia; Sun, Ziyi; Mukai, Jun; Xu, Bin; Fenelon, Karine; Karayiorgou, Maria; Gogos, Joseph A

    2017-07-25

    Identification of protective loss-of-function (LoF) mutations holds great promise for devising novel therapeutic interventions, although it faces challenges due to the scarcity of protective LoF alleles in the human genome. Exploiting the detailed mechanistic characterization of animal models of validated disease mutations offers an alternative. Here, we provide insights into protective-variant biology based on our characterization of a model of the 22q11.2 deletion, a strong genetic risk factor for schizophrenia (SCZ). Postnatal brain up-regulation of Mirta22/Emc10 , an inhibitor of neuronal maturation, represents the major transcriptional effect of the 22q11.2-associated microRNA dysregulation. Here, we demonstrate that mice in which the Df(16)A deficiency is combined with a LoF Mirta22 allele show rescue of key SCZ-related deficits, namely prepulse inhibition decrease, working memory impairment, and social memory deficits, as well as synaptic and structural plasticity abnormalities in the prefrontal cortex. Additional analysis of homozygous Mirta22 knockout mice, in which no alteration is observed in the above-mentioned SCZ-related phenotypes, highlights the deleterious effects of Mirta22 up-regulation. Our results support a causal link between dysregulation of a miRNA target and SCZ-related deficits and provide key insights into beneficial LoF mutations and potential new treatments.

  5. Towards trans-diagnostic mechanisms in psychiatry: neurobehavioral profile of rats with a loss-of-function point mutation in the dopamine transporter gene

    Directory of Open Access Journals (Sweden)

    Valentina Vengeliene

    2017-04-01

    Full Text Available The research domain criteria (RDoC matrix has been developed to reorient psychiatric research towards measurable behavioral dimensions and underlying mechanisms. Here, we used a new genetic rat model with a loss-of-function point mutation in the dopamine transporter (DAT gene (Slc6a3_N157K to systematically study the RDoC matrix. First, we examined the impact of the Slc6a3_N157K mutation on monoaminergic signaling. We then performed behavioral tests representing each of the five RDoC domains: negative and positive valence systems, cognitive, social and arousal/regulatory systems. The use of RDoC may be particularly helpful for drug development. We studied the effects of a novel pharmacological approach metabotropic glutamate receptor mGluR2/3 antagonism, in DAT mutants in a comparative way with standard medications. Loss of DAT functionality in mutant rats not only elevated subcortical extracellular dopamine concentration but also altered the balance of monoaminergic transmission. DAT mutant rats showed deficits in all five RDoC domains. Thus, mutant rats failed to show conditioned fear responses, were anhedonic, were unable to learn stimulus-reward associations, showed impaired cognition and social behavior, and were hyperactive. Hyperactivity in mutant rats was reduced by amphetamine and atomoxetine, which are well-established medications to reduce hyperactivity in humans. The mGluR2/3 antagonist LY341495 also normalized hyperactivity in DAT mutant rats without affecting extracellular dopamine levels. We systematically characterized an altered dopamine system within the context of the RDoC matrix and studied mGluR2/3 antagonism as a new pharmacological strategy to treat mental disorders with underlying subcortical dopaminergic hyperactivity.

  6. Durable broad-spectrum powdery mildew resistance in pea er1 plants is conferred by natural loss-of-function mutations in PsMLO1

    NARCIS (Netherlands)

    Humphry, M.; Reinstädler, A.; Ivanov, S.; Bisseling, T.; Panstruga, R.

    2011-01-01

    Loss-of-function alleles of plant-specific MLO (Mildew Resistance Locus O) genes confer broad-spectrum powdery mildew resistance in monocot (barley) and dicot (Arabidopsis thaliana, tomato) plants. Recessively inherited powdery mildew resistance in pea (Pisum sativum) er1 plants is, in many aspects,

  7. Temporal order of RNase IIIb and loss-of-function mutations during development determines phenotype in pleuropulmonary blastoma / DICER1 syndrome: a unique variant of the two-hit tumor suppression model [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Mark Brenneman

    2018-01-01

    Full Text Available Pleuropulmonary blastoma (PPB is the most frequent pediatric lung tumor and often the first indication of a pleiotropic cancer predisposition, DICER1 syndrome, comprising a range of other individually rare, benign and malignant tumors of childhood and early adulthood. The genetics of DICER1-associated tumorigenesis are unusual in that tumors typically bear neomorphic missense mutations at one of five specific “hotspot” codons within the RNase IIIb domain of DICER 1, combined with complete loss of function (LOF in the other allele. We analyzed a cohort of 124 PPB children for predisposing DICER1 mutations and sought correlations with clinical phenotypes. Over 70% have inherited or de novo germline LOF mutations, most of which truncate the DICER1 open reading frame. We identified a minority of patients who have no germline mutation, but are instead mosaic for predisposing DICER1 mutations. Mosaicism for RNase IIIb domain hotspot mutations defines a special category of DICER1 syndrome patients, clinically distinguished from those with germline or mosaic LOF mutations by earlier onsets and numerous discrete foci of neoplastic disease involving multiple syndromic organ sites. A final category of PBB patients lack predisposing germline or mosaic mutations and have sporadic (rather than syndromic disease limited to a single PPB tumor bearing tumor-specific RNase IIIb and LOF mutations. We propose that acquisition of a neomorphic RNase IIIb domain mutation is the rate limiting event in DICER1-associated tumorigenesis, and that distinct clinical phenotypes associated with mutational categories reflect the temporal order in which LOF and RNase IIIb domain mutations are acquired during development.

  8. De novo loss-of-function mutations in CHD2 cause a fever-sensitive myoclonic epileptic encephalopathy sharing features with Dravet syndrome

    DEFF Research Database (Denmark)

    Suls, Arvid; Jaehn, Johanna A; Kecskés, Angela

    2013-01-01

    CHD2 mutation was identified in an epileptic proband of a second (stage 2) cohort. All three individuals with a CHD2 mutation had intellectual disability and fever-sensitive generalized seizures, as well as prominent myoclonic seizures starting in the second year of life or later. To explore...

  9. Loss-of-Function Mutations in Chitin Responsive Genes Show Increased Susceptibility to the Powdery Mildew Pathogen Erysiphe cichoracearum1[w

    Science.gov (United States)

    Ramonell, Katrina; Berrocal-Lobo, Marta; Koh, Serry; Wan, Jinrong; Edwards, Herb; Stacey, Gary; Somerville, Shauna

    2005-01-01

    Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. The expression patterns elicited by the chito-octamer and hydrolyzed chitin were similar. Microarray expression profiles for several genes were verified via northern analysis or quantitative reverse transcription-PCR. We characterized T-DNA insertion mutants for nine chito-oligomer responsive genes. Three of the mutants were more susceptible to the fungal pathogen, powdery mildew, than wild type as measured by conidiophore production. These three mutants included mutants of genes for two disease resistance-like proteins and a putative E3 ligase. The isolation of loss-of-function mutants with enhanced disease susceptibility provides direct evidence that the chito-octamer is an important oligosaccharide elicitor of plant defenses. Also, this study demonstrates the value of microarray data for identifying new components of uncharacterized signaling pathways. PMID:15923325

  10. Reassessment of the putative role of BLK-p.A71T loss-of-function mutation in MODY and type 2 diabetes

    DEFF Research Database (Denmark)

    Bonnefond, A; Yengo, L; Philippe, J

    2013-01-01

    MODY is believed to be caused by at least 13 different genes. Five rare mutations at the BLK locus, including only one non-synonymous p.A71T variant, were reported to segregate with diabetes in three MODY families. The p.A71T mutation was shown to abolish the enhancing effect of BLK on insulin...... content and secretion from pancreatic beta cell lines. Here, we reassessed the contribution of BLK to MODY and tested the effect of BLK-p.A71T on type 2 diabetes risk and variations in related traits....

  11. Loss-of-function HDAC8 mutations cause a phenotypic spectrum of Cornelia de Lange syndrome-like features, ocular hypertelorism, large fontanelle and X-linked inheritance

    NARCIS (Netherlands)

    Kaiser, Frank J.; Ansari, Morad; Braunholz, Diana; Concepción Gil-Rodríguez, María; Decroos, Christophe; Wilde, Jonathan J.; Fincher, Christopher T.; Kaur, Maninder; Bando, Masashige; Amor, David J.; Atwal, Paldeep S.; Bahlo, Melanie; Bowman, Christine M.; Bradley, Jacquelyn J.; Brunner, Han G.; Clark, Dinah; del Campo, Miguel; Di Donato, Nataliya; Diakumis, Peter; Dubbs, Holly; Dyment, David A.; Eckhold, Juliane; Ernst, Sarah; Ferreira, Jose C.; Francey, Lauren J.; Gehlken, Ulrike; Guillén-Navarro, Encarna; Gyftodimou, Yolanda; Hall, Bryan D.; Hennekam, Raoul; Hudgins, Louanne; Hullings, Melanie; Hunter, Jennifer M.; Yntema, Helger; Innes, A. Micheil; Kline, Antonie D.; Krumina, Zita; Lee, Hane; Leppig, Kathleen; Lynch, Sally Ann; Mallozzi, Mark B.; Mannini, Linda; McKee, Shane; Mehta, Sarju G.; Micule, Ieva; Mohammed, Shehla; Moran, Ellen; Mortier, Geert R.; Moser, Joe-Ann S.; Noon, Sarah E.; Nozaki, Naohito; Nunes, Luis; Pappas, John G.; Penney, Lynette S.; Pérez-Aytés, Antonio; Petersen, Michael B.; Puisac, Beatriz; Revencu, Nicole; Roeder, Elizabeth; Saitta, Sulagna; Scheuerle, Angela E.; Schindeler, Karen L.; Siu, Victoria M.; Stark, Zornitza; Strom, Samuel P.; Thiese, Heidi; Vater, Inga; Willems, Patrick; Williamson, Kathleen; Wilson, Louise C.; Hakonarson, Hakon; Quintero-Rivera, Fabiola; Wierzba, Jolanta; Musio, Antonio; Gillessen-Kaesbach, Gabriele; Ramos, Feliciano J.; Jackson, Laird G.; Shirahige, Katsuhiko; Pié, Juan; Christianson, David W.; Krantz, Ian D.; Fitzpatrick, David R.; Deardorff, Matthew A.

    2014-01-01

    Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80% of cases with typical

  12. Biophysical characterization of the short QT mutation hERG-N588K reveals a mixed gain-and loss-of-function

    DEFF Research Database (Denmark)

    Grunnet, M.; Diness, T.G.; Hansen, R.S.

    2008-01-01

    The short QT syndrome is a newly discovered pro-arrhythmic condition, which may cause ventricular fibrillation and sudden death. Short QT can originate from the apparent gain-of-function mutation N588K in the hERG potassium channel that conducts repolarising I(Kr) current. The present study...

  13. Neurofibromatosis type 1 molecular diagnosis: what can NGS do for you when you have a large gene with loss of function mutations?

    Science.gov (United States)

    Pasmant, Eric; Parfait, Béatrice; Luscan, Armelle; Goussard, Philippe; Briand-Suleau, Audrey; Laurendeau, Ingrid; Fouveaut, Corinne; Leroy, Chrystel; Montadert, Annelore; Wolkenstein, Pierre; Vidaud, Michel; Vidaud, Dominique

    2015-01-01

    Molecular diagnosis of neurofibromatosis type 1 (NF1) is challenging owing to the large size of the tumour suppressor gene NF1, and the lack of mutation hotspots. A somatic alteration of the wild-type NF1 allele is observed in NF1-associated tumours. Genetic heterogeneity in NF1 was confirmed in patients with SPRED1 mutations. Here, we present a targeted next-generation sequencing (NGS) of NF1 and SPRED1 using a multiplex PCR approach (230 amplicons of ∼150 bp) on a PGM sequencer. The chip capacity allowed mixing 48 bar-coded samples in a 4-day workflow. We validated the NGS approach by retrospectively testing 30 NF1-mutated samples, and then prospectively analysed 279 patients in routine diagnosis. On average, 98.5% of all targeted bases were covered by at least 20X and 96% by at least 100X. An NF1 or SPRED1 alteration was found in 246/279 (88%) and 10/279 (4%) patients, respectively. Genotyping throughput was increased over 10 times, as compared with Sanger, with ∼90€ for consumables per sample. Interestingly, our targeted NGS approach also provided quantitative information based on sequencing depth allowing identification of multiexons deletion or duplication. We then addressed the NF1 somatic mutation detection sensitivity in mosaic NF1 patients and tumours. PMID:25074460

  14. Compound Heterozygosity of Low-Frequency Promoter Deletions and Rare Loss-of-Function Mutations in TXNL4A Causes Burn-McKeown Syndrome

    NARCIS (Netherlands)

    Wieczorek, Dagmar; Newman, William G.; Wieland, Thomas; Berulava, Tea; Kaffe, Maria; Falkenstein, Daniela; Beetz, Christian; Graf, Elisabeth; Schwarzmayr, Thomas; Douzgou, Sofia; Clayton-Smith, Jill; Daly, Sarah B.; Williams, Simon G.; Bhaskar, Sanjeev S.; Urquhart, Jill E.; Anderson, Beverley; O'Sullivan, James; Boute, Odile; Gundlach, Jasmin; Czeschik, Johanna Christina; van Essen, Anthonie J.; Hazan, Filiz; Park, Sarah; Hing, Anne; Kuechler, Alma; Lohmann, Dietmar R.; Ludwig, Kerstin U.; Mangold, Elisabeth; Steenpass, Laura; Zeschnigk, Michael; Lemke, Johannes R.; Lourenco, Charles Marques; Hehr, Ute; Prott, Eva-Christina; Waldenberger, Melanie; Boehmer, Anne C.; Horsthemke, Bernhard; O'Keefe, Raymond T.; Meitinger, Thomas; Bum, John; Luedecke, Hermann-Josef; Strom, Tim M.

    2014-01-01

    Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The US spliceosomal complex of eight highly conserved proteins is critical for premRNA splicing. We identified

  15. MFAP5 loss-of-function mutations underscore the involvement of matrix alteration in the pathogenesis of familial thoracic aortic aneurysms and dissections.

    Science.gov (United States)

    Barbier, Mathieu; Gross, Marie-Sylvie; Aubart, Mélodie; Hanna, Nadine; Kessler, Ketty; Guo, Dong-Chuan; Tosolini, Laurent; Ho-Tin-Noe, Benoit; Regalado, Ellen; Varret, Mathilde; Abifadel, Marianne; Milleron, Olivier; Odent, Sylvie; Dupuis-Girod, Sophie; Faivre, Laurence; Edouard, Thomas; Dulac, Yves; Busa, Tiffany; Gouya, Laurent; Milewicz, Dianna M; Jondeau, Guillaume; Boileau, Catherine

    2014-12-04

    Thoracic aortic aneurysm and dissection (TAAD) is an autosomal-dominant disorder with major life-threatening complications. The disease displays great genetic heterogeneity with some forms allelic to Marfan and Loeys-Dietz syndrome, and an important number of cases still remain unexplained at the molecular level. Through whole-exome sequencing of affected members in a large TAAD-affected family, we identified the c.472C>T (p.Arg158(∗)) nonsense mutation in MFAP5 encoding the extracellular matrix component MAGP-2. This protein interacts with elastin fibers and the microfibrillar network. Mutation screening of 403 additional probands identified an additional missense mutation of MFAP5 (c.62G>T [p.Trp21Leu]) segregating with the disease in a second family. Functional analyses performed on both affected individual's cells and in vitro models showed that these two mutations caused pure or partial haploinsufficiency. Thus, alteration of MAGP-2, a component of microfibrils and elastic fibers, appears as an initiating mechanism of inherited TAAD. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  16. Human SOD1 ALS Mutations in a Drosophila Knock-In Model Cause Severe Phenotypes and Reveal Dosage-Sensitive Gain- and Loss-of-Function Components.

    Science.gov (United States)

    Şahin, Aslı; Held, Aaron; Bredvik, Kirsten; Major, Paxton; Achilli, Toni-Marie; Kerson, Abigail G; Wharton, Kristi; Stilwell, Geoff; Reenan, Robert

    2017-02-01

    Amyotrophic Lateral Sclerosis (ALS) is the most common adult-onset motor neuron disease and familial forms can be caused by numerous dominant mutations of the copper-zinc superoxide dismutase 1 (SOD1) gene. Substantial efforts have been invested in studying SOD1-ALS transgenic animal models; yet, the molecular mechanisms by which ALS-mutant SOD1 protein acquires toxicity are not well understood. ALS-like phenotypes in animal models are highly dependent on transgene dosage. Thus, issues of whether the ALS-like phenotypes of these models stem from overexpression of mutant alleles or from aspects of the SOD1 mutation itself are not easily deconvolved. To address concerns about levels of mutant SOD1 in disease pathogenesis, we have genetically engineered four human ALS-causing SOD1 point mutations (G37R, H48R, H71Y, and G85R) into the endogenous locus of Drosophila SOD1 (dsod) via ends-out homologous recombination and analyzed the resulting molecular, biochemical, and behavioral phenotypes. Contrary to previous transgenic models, we have recapitulated ALS-like phenotypes without overexpression of the mutant protein. Drosophila carrying homozygous mutations rendering SOD1 protein enzymatically inactive (G85R, H48R, and H71Y) exhibited neurodegeneration, locomotor deficits, and shortened life span. The mutation retaining enzymatic activity (G37R) was phenotypically indistinguishable from controls. While the observed mutant dsod phenotypes were recessive, a gain-of-function component was uncovered through dosage studies and comparisons with age-matched dsod null animals, which failed to show severe locomotor defects or nerve degeneration. We conclude that the Drosophila knock-in model captures important aspects of human SOD1-based ALS and provides a powerful and useful tool for further genetic studies. Copyright © 2017 by the Genetics Society of America.

  17. Loss-of-function mutations in ISCA2 disrupt 4Fe-4S cluster machinery and cause a fatal leukodystrophy with hyperglycinemia and mtDNA depletion.

    Science.gov (United States)

    Alaimo, Joseph T; Besse, Arnaud; Alston, Charlotte L; Pang, Ki; Appadurai, Vivek; Samanta, Monisha; Smpokou, Patroula; McFarland, Robert; Taylor, Robert W; Bonnen, Penelope E

    2018-04-01

    Iron-sulfur (Fe-S) clusters are essential cofactors for proteins that participate in fundamental cellular processes including metabolism, DNA replication and repair, transcriptional regulation, and the mitochondrial electron transport chain (ETC). ISCA2 plays a role in the biogenesis of Fe-S clusters and a recent report described subjects displaying infantile-onset leukodystrophy due to bi-allelic mutation of ISCA2. We present two additional unrelated cases, and provide a more complete clinical description that includes hyperglycinemia, leukodystrophy of the brainstem with longitudinally extensive spinal cord involvement, and mtDNA deficiency. Additionally, we characterize the role of ISCA2 in mitochondrial bioenergetics and Fe-S cluster assembly using subject cells and ISCA2 cellular knockdown models. Loss of ISCA2 diminished mitochondrial membrane potential, the mitochondrial network, basal and maximal respiration, ATP production, and activity of ETC complexes II and IV. We specifically tested the impact of loss of ISCA2 on 2Fe-2S proteins versus 4Fe-4S proteins and observed deficits in the functioning of 4Fe-4S but not 2Fe-2S proteins. Together these data indicate loss of ISCA2 impaired function of 4Fe-4S proteins resulting in a fatal encephalopathy accompanied by a relatively unusual combination of features including mtDNA depletion alongside complex II deficiency and hyperglycinemia that may facilitate diagnosis of ISCA2 deficiency patients. © 2018 The Authors. Human Mutation published by Wiley Periodicals, Inc.

  18. msbB deletion confers acute sensitivity to CO2 in Salmonella enterica serovar Typhimurium that can be suppressed by a loss-of-function mutation in zwf

    Directory of Open Access Journals (Sweden)

    Troy Kimberly

    2009-08-01

    Full Text Available Abstract Background Pathogens tolerate stress conditions that include low pH, oxidative stress, high salt and high temperature in order to survive inside and outside their hosts. Lipopolysaccharide (LPS, which forms the outer-leaflet of the outer membrane in Gram-negative bacteria, acts as a permeability barrier. The lipid A moiety of LPS anchors it to the outer membrane bilayer. The MsbB enzyme myristoylates the lipid A precursor and loss of this enzyme, in Salmonella, is correlated with reduced virulence and severe growth defects that can both be compensated with extragenic suppressor mutations. Results We report here that msbB (or msbB somA Salmonella are highly sensitive to physiological CO2 (5%, resulting in a 3-log reduction in plating efficiency. Under these conditions, msbB Salmonella form long filaments, bulge and lyse. These bacteria are also sensitive to acidic pH and high osmolarity. Although CO2 acidifies LB broth media, buffering LB to pH 7.5 did not restore growth of msbB mutants in CO2, indicating that the CO2-induced growth defects are not due to the effect of CO2 on the pH of the media. A transposon insertion in the glucose metabolism gene zwf compensates for the CO2 sensitivity of msbB Salmonella. The msbB zwf mutants grow on agar, or in broth, in the presence of 5% CO2. In addition, msbB zwf strains show improved growth in low pH or high osmolarity media compared to the single msbB mutant. Conclusion These results demonstrate that msbB confers acute sensitivity to CO2, acidic pH, and high osmolarity. Disruption of zwf in msbB mutants restores growth in 5% CO2 and results in improved growth in acidic media or in media with high osmolarity. These results add to a growing list of phenotypes caused by msbB and mutations that suppress specific growth defects.

  19. A loss-of-function mutation in the PAS kinase Rim15p is related to defective quiescence entry and high fermentation rates of Saccharomyces cerevisiae sake yeast strains.

    Science.gov (United States)

    Watanabe, Daisuke; Araki, Yuya; Zhou, Yan; Maeya, Naoki; Akao, Takeshi; Shimoi, Hitoshi

    2012-06-01

    Sake yeast cells have defective entry into the quiescent state, allowing them to sustain high fermentation rates. To reveal the underlying mechanism, we investigated the PAS kinase Rim15p, which orchestrates initiation of the quiescence program in Saccharomyces cerevisiae. We found that Rim15p is truncated at the carboxyl terminus in modern sake yeast strains as a result of a frameshift mutation. Introduction of this mutation or deletion of the full-length RIM15 gene in a laboratory strain led to a defective stress response, decreased synthesis of the storage carbohydrates trehalose and glycogen, and impaired G(1) arrest, which together closely resemble the characteristic phenotypes of sake yeast. Notably, expression of a functional RIM15 gene in a modern sake strain suppressed all of these phenotypes, demonstrating that dysfunction of Rim15p prevents sake yeast cells from entering quiescence. Moreover, loss of Rim15p or its downstream targets Igo1p and Igo2p remarkably improved the fermentation rate in a laboratory strain. This finding verified that Rim15p-mediated entry into quiescence plays pivotal roles in the inhibition of ethanol fermentation. Taken together, our results suggest that the loss-of-function mutation in the RIM15 gene may be the key genetic determinant of the increased ethanol production rates in modern sake yeast strains.

  20. Recessive loss-of-function mutations in AP4S1 cause mild fever-sensitive seizures, developmental delay and spastic paraplegia through loss of AP-4 complex assembly

    Science.gov (United States)

    Hardies, Katia; May, Patrick; Djémié, Tania; Tarta-Arsene, Oana; Deconinck, Tine; Craiu, Dana; Helbig, Ingo; Suls, Arvid; Balling, Rudy; Weckhuysen, Sarah; De Jonghe, Peter; Hirst, Jennifer; Afawi, Zaid; Barisic, Nina; Baulac, Stéphanie; Caglayan, Hande; Depienne, Christel; De Kovel, Carolien G.F.; Dimova, Petia; Guerrero-López, Rosa; Guerrini, Renzo; Hjalgrim, Helle; Hoffman-Zacharska, Dorota; Jahn, Johanna; Klein, Karl Martin; Koeleman, Bobby P.C.; Leguern, Eric; Lehesjoki, Anna-Elina; Lemke, Johannes; Lerche, Holger; Marini, Carla; Muhle, Hiltrud; Rosenow, Felix; Serratosa, Jose M.; Møller, Rikke S.; Stephani, Ulrich; Striano, Pasquale; Talvik, Tiina; Von Spiczak, Sarah; Weber, Yvonne; Zara, Federico

    2015-01-01

    We report two siblings with infantile onset seizures, severe developmental delay and spastic paraplegia, in whom whole-genome sequencing revealed compound heterozygous mutations in the AP4S1 gene, encoding the σ subunit of the adaptor protein complex 4 (AP-4). The effect of the predicted loss-of-function variants (p.Gln46Profs*9 and p.Arg97*) was further investigated in a patient's fibroblast cell line. We show that the premature stop mutations in AP4S1 result in a reduction of all AP-4 subunits and loss of AP-4 complex assembly. Recruitment of the AP-4 accessory protein tepsin, to the membrane was also abolished. In retrospect, the clinical phenotype in the family is consistent with previous reports of the AP-4 deficiency syndrome. Our study reports the second family with mutations in AP4S1 and describes the first two patients with loss of AP4S1 and seizures. We further discuss seizure phenotypes in reported patients, highlighting that seizures are part of the clinical manifestation of the AP-4 deficiency syndrome. We also hypothesize that endosomal trafficking is a common theme between heritable spastic paraplegia and some inherited epilepsies. PMID:25552650

  1. Loss-of-Function Mutations in HspR Rescue the Growth Defect of a Mycobacterium tuberculosis Proteasome Accessory Factor E (pafE) Mutant.

    Science.gov (United States)

    Jastrab, Jordan B; Samanovic, Marie I; Copin, Richard; Shopsin, Bo; Darwin, K Heran

    2017-04-01

    Mycobacterium tuberculosis uses a proteasome to degrade proteins by both ATP-dependent and -independent pathways. While much has been learned about ATP-dependent degradation, relatively little is understood about the ATP-independent pathway, which is controlled by Mycobacterium tuberculosis p roteasome a ccessory f actor E (PafE). Recently, we found that a Mycobacterium tuberculosis pafE mutant has slowed growth in vitro and is sensitive to killing by heat stress. However, we did not know if these phenotypes were caused by an inability to degrade the PafE-proteasome substrate HspR ( h eat s hock p rotein r epressor), an inability to degrade any damaged or misfolded proteins, or a defect in another protein quality control pathway. To address this question, we characterized pafE suppressor mutants that grew similarly to pafE + bacteria under normal culture conditions. All but one suppressor mutant analyzed contained mutations that inactivated HspR function, demonstrating that the slowed growth and heat shock sensitivity of a pafE mutant were caused primarily by the inability of the proteasome to degrade HspR. IMPORTANCE Mycobacterium tuberculosis encodes a proteasome that is highly similar to eukaryotic proteasomes and is required for virulence. We recently discovered a proteasome cofactor, PafE, which is required for the normal growth, heat shock resistance, and full virulence of M. tuberculosis In this study, we demonstrate that PafE influences this phenotype primarily by promoting the expression of protein chaperone genes that are necessary for surviving proteotoxic stress. Copyright © 2017 American Society for Microbiology.

  2. Loss-of-function variants in the filaggrin gene are a significant risk factor for peanut allergy

    NARCIS (Netherlands)

    Brown, Sara J.; Asai, Yuka; Cordell, Heather J.; Campbell, Linda E.; Zhao, Yiwei; Liao, Haihui; Northstone, Kate; Henderson, John; Alizadehfar, Reza; Ben-Shoshan, Moshe; Morgan, Kenneth; Roberts, Graham; Masthoff, Laury J. N.; Pasmans, Suzanne G. M. A.; van den Akker, Peter C.; Wijmenga, Cisca; Hourihane, Jonathan O'B.; Palmer, Colin N. A.; Lack, Gideon; Clarke, Ann; Hull, Peter R.; Irvine, Alan D.; McLean, W. H. Irwin

    Background: IgE-mediated peanut allergy is a complex trait with strong heritability, but its genetic basis is currently unknown. Loss-of-function mutations within the filaggrin gene are associated with atopic dermatitis and other atopic diseases; therefore, filaggrin is a candidate gene in the

  3. The loss-of-function disease-mutation G301R in the Na+/K+-ATPase α2 isoform decreases lesion volume and improves functional outcome after spinal cord injury in mice

    DEFF Research Database (Denmark)

    Ellman, Ditte Gry; Isaksen, Toke Jost; Lund, Minna Christiansen

    2017-01-01

    to anaerobic metabolism and lactate accumulation. During ischemia, Na(+)/K(+)-ATPase-related functions will naturally increase the energy demand of the Na(+)/K(+)-ATPase ion pump. However, the role of the α2Na(+)/K(+)-ATPase in contusion injury to the spinal cord remains unknown. We used mice heterozygous mice...... for the loss-of-function disease-mutation G301R in the Atp1a2 gene (α 2(+/G301R) ) to study the effect of reduced α2Na(+)/K(+)-ATPase expression in a moderate contusion spinal cord injury (SCI) model. RESULTS: We found that α 2(+/G301R) mice display significantly improved functional recovery and decreased...... as no apparent differences were observed in location and activation of CD45 and F4/80 positive microglia and infiltrating leukocytes. CONCLUSION: Our proof of concept study demonstrates that reduced expression of the α2 isoform in the spinal cord is protective following SCI. Importantly, the BMS and lesion...

  4. Cloning of the Epstein-Barr virus-related rhesus lymphocryptovirus as a bacterial artificial chromosome: a loss-of-function mutation of the rhBARF1 immune evasion gene.

    Science.gov (United States)

    Ohashi, Makoto; Orlova, Nina; Quink, Carol; Wang, Fred

    2011-02-01

    Rhesus macaques are naturally infected with a gammaherpesvirus which is in the same lymphocryptovirus (LCV) genus as and closely related to Epstein-Barr virus (EBV). The rhesus macaque LCV (rhLCV) contains a repertoire of genes identical to that of EBV, and experimental rhLCV infection of naive rhesus macaques accurately models acute and persistent EBV infection of humans. We cloned the LCL8664 rhLCV strain as a bacterial artificial chromosome to create recombinant rhLCV for investigation in this animal model system. A recombinant rhLCV (clone 16 rhLCV) carrying a mutation in the putative immune evasion gene rhBARF1 was created along with a rescued wild-type (rWT) rhLCV in which the rhBARF1 open reading frame (ORF) was repaired. The rWT rhLCV molecular clone demonstrated viral replication and B-cell immortalization properties comparable to those of the naturally derived LCL8664 rhLCV. Qualitatively, clone 16 rhLCV carrying a mutated rhBARF1 was competent for viral replication and B-cell immortalization, but quantitative assays showed that clone 16 rhLCV immortalized B cells less efficiently than LCL8664 and rWT rhLCV. Functional studies showed that rhBARF1 could block CSF-1 cytokine signaling as well as EBV BARF1, whereas the truncated rhBARF1 from clone 16 rhLCV was a loss-of-function mutant. These recombinant rhLCV can be used in the rhesus macaque animal model system to better understand how a putative viral immune evasion gene contributes to the pathogenesis of acute and persistent EBV infection. The development of a genetic system for making recombinant rhLCV constitutes a major advance in the study of EBV pathogenesis in the rhesus macaque animal model.

  5. Identification of IbeR as a Stationary-Phase Regulator in Meningitic Escherichia coli K1 that Carries a Loss-of-Function Mutation in rpoS

    Directory of Open Access Journals (Sweden)

    Feng Chi

    2009-01-01

    Full Text Available IbeR is a regulator present in meningitic Escherichia coli strain E44 that carries a loss-of-function mutation in the stationary-phase (SP regulatory gene rpoS. In order to determine whether IbeR is an SP regulator in E44, two-dimensional gel electrophoresis and LC-MS were used to compare the proteomes of a noninvasive ibeR deletion mutant BR2 and its parent strain E44 in the SP. Four up-regulated (TufB, GapA, OmpA, AhpC and three down-regulated (LpdA, TnaA, OpmC proteins in BR2 were identified when compared to E44. All these proteins contribute to energy metabolism or stress resistance, which is related to SP regulation. One of the down-regulated proteins, tryptophanase (TnaA, which is regulated by RpoS in other E. coli strains, is associated with SP regulation via production of a signal molecule indole. Our studies demonstrated that TnaA was required for E44 invasion, and that indole was able to restore the noninvasive phenotype of the tnaA mutant. The production of indole was significantly reduced in BR2, indicating that ibeR is required for the indole production via tnaA. Survival studies under different stress conditions indicated that IbeR contributed to bacteria stress resistance in the SP. Taken together, IbeR is a novel regulator contributing to the SP regulation.

  6. The loss-of-function disease-mutation G301R in the Na+/K+-ATPase α2 isoform decreases lesion volume and improves functional outcome after acute spinal cord injury in mice.

    Science.gov (United States)

    Ellman, Ditte Gry; Isaksen, Toke Jost; Lund, Minna Christiansen; Dursun, Safinaz; Wirenfeldt, Martin; Jørgensen, Louise Helskov; Lykke-Hartmann, Karin; Lambertsen, Kate Lykke

    2017-09-08

    The Na + /K + -ATPases are transmembrane ion pumps important for maintenance of ion gradients across the plasma membrane that serve to support multiple cellular functions, such as membrane potentials, regulation of cellular volume and pH, and co-transport of signaling transmitters in all animal cells. The α 2 Na + /K + -ATPase subunit isoform is predominantly expressed in astrocytes, which us the sharp Na + -gradient maintained by the sodium pump necessary for astroglial metabolism. Prolonged ischemia induces an elevation of [Na + ] i , decreased ATP levels and intracellular pH owing to anaerobic metabolism and lactate accumulation. During ischemia, Na + /K + -ATPase-related functions will naturally increase the energy demand of the Na + /K + -ATPase ion pump. However, the role of the α 2 Na + /K + -ATPase in contusion injury to the spinal cord remains unknown. We used mice heterozygous mice for the loss-of-function disease-mutation G301R in the Atp1a2 gene (α 2 +/G301R ) to study the effect of reduced α 2 Na + /K + -ATPase expression in a moderate contusion spinal cord injury (SCI) model. We found that α 2 +/G301R mice display significantly improved functional recovery and decreased lesion volume compared to littermate controls (α 2 +/+ ) 7 days after SCI. The protein level of the α 1 isoform was significantly increased, in contrast to the α 3 isoform that significantly decreased 3 days after SCI in both α 2 +/G301R and α 2 +/+ mice. The level of the α 2 isoform was significantly decreased in α 2 +/G301R mice both under naïve conditions and 3 days after SCI compared to α 2 +/+ mice. We found no differences in astroglial aquaporin 4 levels and no changes in the expression of chemokines (CCL2, CCL5 and CXCL1) and cytokines (TNF, IL-6, IL-1β, IL-10 and IL-5) between genotypes, just as no apparent differences were observed in location and activation of CD45 and F4/80 positive microglia and infiltrating leukocytes. Our proof of concept study

  7. Fitness is strongly influenced by rare mutations of large effect in a microbial mutation accumulation experiment.

    Science.gov (United States)

    Heilbron, Karl; Toll-Riera, Macarena; Kojadinovic, Mila; MacLean, R Craig

    2014-07-01

    Our understanding of the evolutionary consequences of mutation relies heavily on estimates of the rate and fitness effect of spontaneous mutations generated by mutation accumulation (MA) experiments. We performed a classic MA experiment in which frequent sampling of MA lines was combined with whole genome resequencing to develop a high-resolution picture of the effect of spontaneous mutations in a hypermutator (ΔmutS) strain of the bacterium Pseudomonas aeruginosa. After ∼644 generations of mutation accumulation, MA lines had accumulated an average of 118 mutations, and we found that average fitness across all lines decayed linearly over time. Detailed analyses of the dynamics of fitness change in individual lines revealed that a large fraction of the total decay in fitness (42.3%) was attributable to the fixation of rare, highly deleterious mutations (comprising only 0.5% of fixed mutations). Furthermore, we found that at least 0.64% of mutations were beneficial and probably fixed due to positive selection. The majority of mutations that fixed (82.4%) were base substitutions and we failed to find any signatures of selection on nonsynonymous or intergenic mutations. Short indels made up a much smaller fraction of the mutations that were fixed (17.4%), but we found evidence of strong selection against indels that caused frameshift mutations in coding regions. These results help to quantify the amount of natural selection present in microbial MA experiments and demonstrate that changes in fitness are strongly influenced by rare mutations of large effect. Copyright © 2014 by the Genetics Society of America.

  8. [Multiple sclerosis, loss of functionality and gender].

    Science.gov (United States)

    Bravo-González, Félix; Álvarez-Roldán, Arturo

    2017-12-01

    To identify the type of support and assistance that patients with multiple sclerosis need in order to cope with the loss of functionality, and to show how gender affects the perception of these needs. Interpretative-phenomenological qualitative study. Granada (Spain). Year: 2014. Intentional sample: 30 patients and 20 family caregivers. Data were gathered from 26 interviews and 4 focus groups. The data were coded and analysed with the NVivo programme. The multiple sclerosis patients and family caregivers had different perceptions of the loss of capacity to undertake activities of daily living. Being able to self care was considered the last vestige of autonomy. The women with multiple sclerosis tried to take on the responsibility of housework, but the male caregivers became gradually involved in these tasks. Gender roles were redefined with respect to housekeeping. The multiple sclerosis patients showed a need for emotional support. Some of the men had abandoned the stereotype of the strong male as a result of the decline in their health. Adaptations in the home took place without planning them in advance. The use of mobility devices started on an occasional basis. A fear of stigma was an obstacle for regular use of assistive technology. Health care for people with multiple sclerosis should include family caregivers. Gender influences the perception that caregivers and patients have of the assistance they require to maximise their quality of life. This flags up several intervention areas for the follow-up and long-term care of these patients by the healthcare system. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Filaggrin loss-of-function mutation R501X and 2282del4 carrier status is associated with fissured skin on the hands: results from a cross-sectional population study

    DEFF Research Database (Denmark)

    Thyssen, J P; Ross-Hansen, K; Johansen, J D

    2012-01-01

    tested. Results: In an adjusted logistic regression analysis, filaggrin mutation status was significantly associated with fissured skin on the hands and/or fingers in adults (OR=1.93; CI95%=1.05-3.55) and a near significant negative interaction with atopic dermatitis (p=0.055), suggesting the effect...

  10. Alzheimer's disease due to loss of function

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2016-01-01

    Alzheimer's Disease (AD) is a highly complex disease involving a broad range of clinical, cellular, and biochemical manifestations that are currently not understood in combination. This has led to many views of AD, e.g. the amyloid, tau, presenilin, oxidative stress, and metal hypotheses....... The amyloid hypothesis has dominated the field with its assumption that buildup of pathogenic β-amyloid (Aβ) peptide causes disease. This paradigm has been criticized, yet most data suggest that Aβ plays a key role in the disease. Here, a new loss-of-function hypothesis is synthesized that accounts...

  11. Recessive loss-of-function mutations in AP4S1 cause mild fever-sensitive seizures, developmental delay and spastic paraplegia through loss of AP-4 complex assembly

    DEFF Research Database (Denmark)

    Hardies, Katia; May, Patrick; Djémié, Tania

    2015-01-01

    We report two siblings with infantile onset seizures, severe developmental delay and spastic paraplegia, in whom whole-genome sequencing revealed compound heterozygous mutations in the AP4S1 gene, encoding the σ subunit of the adaptor protein complex 4 (AP-4). The effect of the predicted loss-of-...... in reported patients, highlighting that seizures are part of the clinical manifestation of the AP-4 deficiency syndrome. We also hypothesize that endosomal trafficking is a common theme between heritable spastic paraplegia and some inherited epilepsies....

  12. IKs Gain- and Loss-of-Function In Early-Onset Lone Atrial Fibrillation

    DEFF Research Database (Denmark)

    Steffensen, Annette Buur; Refsgaard, Lena; Andersen, Martin Nybo

    2015-01-01

    were found in genes previously associated with AF. The mutations A46T, R195W, and A302V have previously been associated with long-QT syndrome. In line with previous reports, we found A302V to display a pronounced loss-of-function of the IKs current, while the other mutants exhibited a gain...

  13. Loss of function of the HSFA9 seed longevity program.

    Science.gov (United States)

    Tejedor-Cano, Javier; Prieto-Dapena, Pilar; Almoguera, Concepción; Carranco, Raúl; Hiratsu, Keiichiro; Ohme-Takagi, Masaru; Jordano, Juan

    2010-08-01

    Gain of function approaches that have been published by our laboratory determined that HSFA9 (Heat Shock Factor A9) activates a genetic program contributing to seed longevity and to desiccation tolerance in plant embryos. We now evaluate the role(s) of HSFA9 by loss of function using different modified forms of HaHSFA9 (sunflower HSFA9), which were specifically overexpressed in seeds of transgenic tobacco. We used two inactive forms (M1, M2) with deletion or mutation of the transcription activation domain of HaHSFA9, and a third form (M3) with HaHSFA9 converted to a potent active repressor by fusion of the SRDX motif. The three forms showed similar protein accumulation in transgenic seeds; however, only HaHSFA9-SRDX showed a highly significant reduction of seed longevity, as determined by controlled deterioration tests, a rapid seed ageing procedure. HaHSFA9-SRDX impaired the genetic program controlled by the tobacco HSFA9, with a drastic reduction in the accumulation of seed heat shock proteins (HSPs) including seed-specific small HSP (sHSP) belonging to cytosolic (CI, CII) classes. Despite such effects, the HaHSFA9-SRDX seeds could survive developmental desiccation during embryogenesis and their subsequent germination was not reduced. We infer that the HSFA9 genetic program contributes only partially to seed-desiccation tolerance and longevity.

  14. Strong sexual selection in males against a mutation load that reduces offspring production in seed beetles.

    Science.gov (United States)

    Grieshop, K; Stångberg, J; Martinossi-Allibert, I; Arnqvist, G; Berger, D

    2016-06-01

    Theory predicts that sexual reproduction can increase population viability relative to asexual reproduction by allowing sexual selection in males to remove deleterious mutations from the population without large demographic costs. This requires that selection acts more strongly in males than females and that mutations affecting male reproductive success have pleiotropic effects on population productivity, but empirical support for these assumptions is mixed. We used the seed beetle Callosobruchus maculatus to implement a three-generation breeding design where we induced mutations via ionizing radiation (IR) in the F0 generation and measured mutational effects (relative to nonirradiated controls) on an estimate of population productivity in the F1 and effects on sex-specific competitive lifetime reproductive success (LRS) in the F2 . Regardless of whether mutations were induced via F0 males or females, they had strong negative effects on male LRS, but a nonsignificant influence on female LRS, suggesting that selection is more efficient in removing deleterious alleles in males. Moreover, mutations had seemingly shared effects on population productivity and competitive LRS in both sexes. Thus, our results lend support to the hypothesis that strong sexual selection on males can act to remove the mutation load on population viability, thereby offering a benefit to sexual reproduction. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  15. PHENOTYPIC ANALYSIS OF OsTPKb LOSS OF FUNCTION MUTANT RICE LINES

    Directory of Open Access Journals (Sweden)

    Isayenkov S. V.

    2015-08-01

    Full Text Available The results of screen and analysis of two OsTPKb rice mutant lines were described. The phenotypes and growth rate level of homozygous mutant plants of both rice lines were estimated. The electron microscopy of aleurone layer from forming seeds was performed. The OsTPKb mutant plants demonstrate lower growth rate in comparison with wild type plants. The loss of function OsTPKb mutations invariably led to (semisterile rice plants. The functional disruption of OsTPKb channel has negative impact on plant growth and development. It might completely change the cell morphology of aleurone layer.

  16. Nocturnal frontal lobe epilepsy with paroxysmal arousals due to CHRNA2 loss of function.

    Science.gov (United States)

    Conti, Valerio; Aracri, Patrizia; Chiti, Laura; Brusco, Simone; Mari, Francesco; Marini, Carla; Albanese, Maria; Marchi, Angela; Liguori, Claudio; Placidi, Fabio; Romigi, Andrea; Becchetti, Andrea; Guerrini, Renzo

    2015-04-14

    We assessed the mutation frequency in nicotinic acetylcholine receptor (nAChR) subunits CHRNA4, CHRNB2, and CHRNA2 in a cohort including autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and sporadic nocturnal frontal lobe epilepsy (NFLE). Upon finding a novel mutation in CHRNA2 in a large family, we tested in vitro its functional effects. We sequenced all the coding exons and their flanking intronic regions in 150 probands (73 NFLE, 77 ADNFLE), in most of whom diagnosis had been validated by EEG recording of seizures. Upon finding a missense mutation in CHRNA2, we measured whole-cell currents in human embryonic kidney cells in both wild-type and mutant α2β4 and α2β2 nAChR subtypes stimulated with nicotine. We found a c.889A>T (p.Ile297Phe) mutation in the proband (≈0.6% of the whole cohort) of a large ADNFLE family (1.2% of familial cases) and confirmed its segregation in all 6 living affected individuals. Video-EEG studies demonstrated sleep-related paroxysmal epileptic arousals in all mutation carriers. Oxcarbazepine treatment was effective in all. Whole-cell current density was reduced to about 40% in heterozygosity and to 0% in homozygosity, with minor effects on channel permeability and sensitivity to nicotine. ADNFLE had previously been associated with CHRNA2 dysfunction in one family, in which a gain of function mutation was demonstrated. We confirm the causative role of CHRNA2 mutations in ADNFLE and demonstrate that also loss of function of α2 nAChRs may have pathogenic effects. CHRNA2 mutations are a rare cause of ADNFLE but this gene should be included in mutation screening. © 2015 American Academy of Neurology.

  17. Mutations at the Qo-Site of the Cytochrome bc1 Complex Strongly Affect Oxygen Binding

    DEFF Research Database (Denmark)

    Husen, Peter; Solov'yov, Ilia A

    2017-01-01

    The homodimeric bc1 protein complex is embedded in membranes of mitochondria and photosynthetic bacteria, where it transports protons across the membrane to maintain an electrostatic potential used to drive ATP synthesis as part of the respiratory or photosynthetic pathways. The reaction cycle...... of the bc1 complex is driven by series of redox processes involving substrate molecules from the membrane, but occasional side reactions between an intermediate semiquinone substrate and molecular oxygen are suspected to be a source of toxic superoxide, which is believed to be a factor in aging. The present...... investigation employs molecular dynamics simulations to study the effect of mutations in the Qo binding sites of the bc1 complex on the ability of oxygen molecules to migrate to and bind at various locations within the complex. It is found that the mutations strongly affect the ability of oxygen to bind...

  18. The diagnostic and therapeutic aspects of loss-of-function cardiac sodium channelopathies in children.

    Science.gov (United States)

    Chockalingam, Priya; Clur, Sally-Ann B; Breur, Johannes M P J; Kriebel, Thomas; Paul, Thomas; Rammeloo, Lukas A; Wilde, Arthur A M; Blom, Nico A

    2012-12-01

    Loss-of-function sodium channelopathies manifest as a spectrum of diseases including Brugada syndrome (BrS) and cardiac conduction disease. To analyze the diagnostic and therapeutic aspects of these disorders in children. Patients aged ≤ 16 years with genetically confirmed loss-of-function sodium channelopathies (SCN5A mutation), presenting with cardiac symptoms, positive family history, and/or abnormal electrocardiogram (ECG), were included. Abnormal ECG consisted of type 1 BrS ECG and/or prolonged conduction intervals (PR interval/QRS duration > 98th percentile for age). Among the cohort (n = 33, age 6 ± 5 years, 58% male subjects, 30% probands), 14 (42%) patients were symptomatic, presenting with syncope (n = 5), palpitations (n = 1), supraventricular arrhythmias (n = 3), aborted cardiac arrest (n = 3), and sudden cardiac death (n = 2). Heart rate was 91 ± 26 beats/min, PR interval 168 ± 35 ms, QRS duration 112 ± 20 ms, and heart-rate corrected QT interval 409 ± 26 ms. Conduction intervals were prolonged in 28 (85%) patients; 6 of these patients also had spontaneous type 1 BrS ECG. Eight fever-associated events occurred in 6 patients; 2 of these were vaccination-related fever episodes. Treatment included aggressive antipyretics during fever in all patients; antiarrhythmic treatment included implantable cardioverter-defibrillator (n = 4), pacemaker (n = 2), and beta-blockers, either alone (n = 3) or in combination with device (n = 2). During follow-up (4 ± 4 years), 2 previously symptomatic patients had monomorphic ventricular tachycardia; there were no deaths. Diagnosis of loss-of-function sodium channelopathies in children relies on cardiac symptoms, family history, and ECG. Fever and vaccination are potential arrhythmia triggers; conduction delay is the commonest finding on ECG. Beta-blockers have a role in preventing tachycardia-induced arrhythmias; implantable cardioverter-defibrillator should probably be reserved for severe cases. Copyright © 2012

  19. Loss-of-function of the voltage-gated sodium channel NaV1.5 (channelopathies) in patients with irritable bowel syndrome.

    Science.gov (United States)

    Beyder, Arthur; Mazzone, Amelia; Strege, Peter R; Tester, David J; Saito, Yuri A; Bernard, Cheryl E; Enders, Felicity T; Ek, Weronica E; Schmidt, Peter T; Dlugosz, Aldona; Lindberg, Greger; Karling, Pontus; Ohlsson, Bodil; Gazouli, Maria; Nardone, Gerardo; Cuomo, Rosario; Usai-Satta, Paolo; Galeazzi, Francesca; Neri, Matteo; Portincasa, Piero; Bellini, Massimo; Barbara, Giovanni; Camilleri, Michael; Locke, G Richard; Talley, Nicholas J; D'Amato, Mauro; Ackerman, Michael J; Farrugia, Gianrico

    2014-06-01

    SCN5A encodes the α-subunit of the voltage-gated sodium channel NaV1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of NaV1.5. We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls. Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted NaV1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-NaV1.5 had the greatest effect in reducing NaV1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS. About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt NaV1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  20. A wild origin of the loss-of-function lycopene beta cyclase (CYC-b) allele in cultivated, red-fleshed papaya (Carica papaya).

    Science.gov (United States)

    Wu, Meng; Lewis, Jamicia; Moore, Richard C

    2017-01-01

    The red flesh of some papaya cultivars is caused by a recessive loss-of-function mutation in the coding region of the chromoplast-specific lycopene beta cyclase gene (CYC-b). We performed an evolutionary genetic analysis of the CYC-b locus in wild and cultivated papaya to uncover the origin of this loss-of-function allele in cultivated papaya. We analyzed the levels and patterns of genetic diversity at the CYC-b locus and six loci in a 100-kb region flanking CYC-b and compared these to genetic diversity levels at neutral autosomal loci. The evolutionary relationships of CYC-b haplotypes were assessed using haplotype network analysis of the CYC-b locus and the 100-kb CYC-b region. Genetic diversity at the recessive CYC-b allele (y) was much lower relative to the dominant Y allele found in yellow-fleshed wild and cultivated papaya due to a strong selective sweep. Haplotype network analyses suggest the y allele most likely arose in the wild and was introduced into domesticated varieties after the first papaya domestication event. The shared haplotype structure between some wild, feral, and cultivated haplotypes around the y allele supports subsequent escape of this allele from red cultivars back into wild populations through feral intermediates. Our study supports a protracted domestication process of papaya through the introgression of wild-derived traits and gene flow from cultivars to wild populations. Evidence of gene flow from cultivars to wild populations through feral intermediates has implications for the introduction of transgenic papaya into Central American countries. © 2017 Botanical Society of America.

  1. Target genes of myostatin loss-of-function in muscles of late bovine fetuses

    Directory of Open Access Journals (Sweden)

    Hocquette Jean-François

    2007-03-01

    Full Text Available Abstract Background Myostatin, a muscle-specific member of the Transforming Growth Factor beta family, negatively regulates muscle development. Double-muscled (DM cattle have a loss-of-function mutation in their myostatin gene responsible for the hypermuscular phenotype. Thus, these animals are a good model for understanding the mechanisms underpinning muscular hypertrophy. In order to identify individual genes or networks that may be myostatin targets, we looked for genes that were differentially expressed between DM and normal (NM animals (n = 3 per group in the semitendinosus muscle (hypertrophied in DM animals at 260 days of fetal development (when the biochemical differentiation of muscle is intensive. A heterologous microarray (human and murine oligonucleotide sequences of around 6,000 genes expressed in muscle was used. Results Many genes were found to be differentially expressed according to genetic type (some with a more than 5-fold change, and according to the presence of one or two functional myostatin allele(s. They belonged to various functional categories. The genes down-regulated in DM fetuses were mainly those encoding extracellular matrix proteins, slow contractile proteins and ribosomal proteins. The genes up-regulated in DM fetuses were mainly involved in the regulation of transcription, cell cycle/apoptosis, translation or DNA metabolism. These data highlight features indicating that DM muscle is shifted towards a more glycolytic metabolism, and has an altered extracellular matrix composition (e.g. down-regulation of COL1A1 and COL1A2, and up-regulation of COL4A2 and decreased adipocyte differentiation (down-regulation of C1QTNF3. The altered gene expression in the three major muscle compartments (fibers, connective tissue and intramuscular adipose tissue is consistent with the well-known characteristics of DM cattle. In addition, novel potential targets of the myostatin gene were identified (MB, PLN, troponins, ZFHX1B

  2. Biallelic Loss of Function of SORL1 in an Early Onset Alzheimer's Disease Patient.

    Science.gov (United States)

    Le Guennec, Kilan; Tubeuf, Hélène; Hannequin, Didier; Wallon, David; Quenez, Olivier; Rousseau, Stéphane; Richard, Anne-Claire; Deleuze, Jean-François; Boland, Anne; Frebourg, Thierry; Gaildrat, Pascaline; Campion, Dominique; Martins, Alexandra; Nicolas, Gaël

    2018-01-01

    Heterozygous SORL1 protein truncating variants (PTV) are a strong risk factor for early-onset Alzheimer's disease (EOAD). In case control studies performed at the genome-wide level, PTV definition is usually straightforward. Regarding splice site variants, only those affecting canonical sites are typically included. Some other variants, not annotated as PTV, could, however, affect splicing and hence result in a loss of SORL1 function. We took advantage of the whole exome sequencing data from the 9/484 patients with a previously reported SORL1 PTV in the French EOAD series and searched for a second variant which may affect splicing and eventually result in more than 50% loss of function overall. We found that one patient, known to carry a variant predicted to disrupt the canonical 5' splice site of exon 8, also carried a second novel intronic variant predicted to affect SORL1 splicing of exon 29. Segregation analysis showed that the second variant was located in trans from the known PTV. We performed ex vivo minigene splicing assays and showed that both variants led to the generation of transcripts containing a premature stop codon. This is therefore the first evidence of a human carrying biallelic SORL1 PTV. This patient had a family history of dementia in both maternal and paternal lineages with later ages of onset than the proband himself. However, his 55 years age at onset was in the same ranges as previously published SORL1 heterozygous PTV carriers. This suggests that biallelic loss of SORL1 function is an extremely rare event that was not associated with a dramatically earlier age at onset than heterozygous SORL1 loss-of-function variant carriers, in this single patient.

  3. Genetic Load of Loss-of-Function Polymorphic Variants in Great Apes.

    Science.gov (United States)

    de Valles-Ibáñez, Guillem; Hernandez-Rodriguez, Jessica; Prado-Martinez, Javier; Luisi, Pierre; Marquès-Bonet, Tomàs; Casals, Ferran

    2016-03-26

    Loss of function (LoF) genetic variants are predicted to disrupt gene function, and are therefore expected to substantially reduce individual's viability. Knowing the genetic burden of LoF variants in endangered species is of interest for a better understanding of the effects of declining population sizes on species viability. In this study, we have estimated the number of LoF polymorphic variants in six great ape populations, based on whole-genome sequencing data in 79 individuals. Our results show that although the number of functional variants per individual is conditioned by the effective population size, the number of variants with a drastic phenotypic effect is very similar across species. We hypothesize that for those variants with high selection coefficients, differences in effective population size are not important enough to affect the efficiency of natural selection to remove them. We also describe that mostly CpG LoF mutations are shared across species, and an accumulation of LoF variants at olfactory receptor genes in agreement with its pseudogenization in humans and other primate species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. A Matter of Taste: Lineage-Specific Loss of Function of Taste Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Marco Antinucci

    2017-11-01

    Full Text Available Vertebrates can perceive at least five different taste qualities, each of which is thought to have a specific role in the evolution of different species. The avoidance of potentially poisonous foods, which are generally bitter or sour tasting, and the search for more nutritious ones, those with high-fat and high-sugar content, are two of the most well-known examples. The study of taste genes encoding receptors that recognize ligands triggering taste sensations has helped to reconstruct several evolutionary adaptations to dietary changes. In addition, an increasing number of studies have focused on pseudogenes, genomic DNA sequences that have traditionally been considered defunct relatives of functional genes mostly because of the presence of deleterious mutations interrupting their open reading frames. The study of taste receptor pseudogenes has helped to shed light on how the evolutionary history of taste in vertebrates has been the result of a succession of gene gain and loss processes. This dynamic role in evolution has been explained by the “less-is-more” hypothesis, suggesting gene loss as a mechanism of evolutionary change in response to a dietary shift. This mini-review aims at depicting the major lineage-specific loss of function of taste receptor genes in vertebrates, stressing their evolutionary importance and recapitulating signatures of natural selection and their correlations with food habits.

  5. Loss-of-Function Mutations in HOXC13 Cause Pure Hair and Nail Ectodermal Dysplasia

    OpenAIRE

    Lin, Zhimiao; Chen, Quan; Shi, Lei; Lee, Mingyang; Giehl, Kathrin A.; Tang, Zhanli; Wang, Huijun; Zhang, Jie; Yin, Jinghua; Wu, Lingshen; Xiao, Ruo; Liu, Xuanzhu; Dai, Lanlan; Zhu, Xuejun; Li, Ruoyu

    2012-01-01

    Pure hair and nail ectodermal dysplasia (PHNED) is a congenital condition characterized by hypotrichosis and nail dystrophy. Autosomal-recessive PHNED has previously been mapped to chromosomal region 12q12-q14.1, which contains the type II hair keratin and HOXC clusters. Hoxc13-null mice are known to develop hair and nail defects very similar to those seen in human PHNED. We performed whole-exome sequencing in a consanguineous Chinese family affected by PHNED and identified a homozygous nonse...

  6. Loss-of-Function FANCL Mutations Associate with Severe Fanconi Anemia Overlapping the VACTERL Association

    NARCIS (Netherlands)

    Vetro, Annalisa; Iascone, Maria; Limongelli, Ivan; Ameziane, Najim; Gana, Simone; Mina, Erika Della; Giussani, Ursula; Ciccone, Roberto; Forlino, Antonella; Pezzoli, Laura; Rooimans, Martin A.; van Essen, Ton; Messa, Jole; Rizzuti, Tommaso; Bianchi, Paolo; Dorsman, Josephine; de Winter, Johan P.; Lalatta, Faustina; Zuffardi, Orsetta

    The diagnosis of VACTERL syndrome can be elusive, especially in the prenatal life, due to the presence of malformations that overlap those present in other genetic conditions, including the Fanconi anemia (FA). We report on three VACTERL cases within two families, where the two who arrived to be

  7. Arts syndrome is caused by loss-of-function mutations in PRPS1

    NARCIS (Netherlands)

    de Brouwer, Arjan P. M.; Williams, Kelly L.; Duley, John A.; van Kuilenburg, Andre B. P.; Nabuurs, Sander B.; Egmont-Petersen, Michael; Lugtenberg, Dorien; Zoetekouw, Lida; Banning, Martijn J. G.; Roeffen, Melissa; Hamel, Ben C. J.; Weaving, Linda; Ouvrier, Robert A.; Donald, Jennifer A.; Wevers, Ron A.; Christodoulou, John; van Bokhoven, Hans

    2007-01-01

    Arts syndrome is an X-linked disorder characterized by mental retardation, early-onset hypotonia, ataxia, delayed motor development, hearing impairment, and optic atrophy. Linkage analysis in a Dutch family and an Australian family suggested that the candidate gene maps to Xq22.1-q24.

  8. Loss-of-Function Mutations in FRRS1L Lead to an Epileptic-Dyskinetic Encephalopathy.

    Science.gov (United States)

    Madeo, Marianna; Stewart, Michelle; Sun, Yuyang; Sahir, Nadia; Wiethoff, Sarah; Chandrasekar, Indra; Yarrow, Anna; Rosenfeld, Jill A; Yang, Yaping; Cordeiro, Dawn; McCormick, Elizabeth M; Muraresku, Colleen C; Jepperson, Tyler N; McBeth, Lauren J; Seidahmed, Mohammed Zain; El Khashab, Heba Y; Hamad, Muddathir; Azzedine, Hamid; Clark, Karl; Corrochano, Silvia; Wells, Sara; Elting, Mariet W; Weiss, Marjan M; Burn, Sabrina; Myers, Angela; Landsverk, Megan; Crotwell, Patricia L; Waisfisz, Quinten; Wolf, Nicole I; Nolan, Patrick M; Padilla-Lopez, Sergio; Houlden, Henry; Lifton, Richard; Mane, Shrikant; Singh, Brij B; Falk, Marni J; Mercimek-Mahmutoglu, Saadet; Bilguvar, Kaya; Salih, Mustafa A; Acevedo-Arozena, Abraham; Kruer, Michael C

    2016-06-02

    Glutamatergic neurotransmission governs excitatory signaling in the mammalian brain, and abnormalities of glutamate signaling have been shown to contribute to both epilepsy and hyperkinetic movement disorders. The etiology of many severe childhood movement disorders and epilepsies remains uncharacterized. We describe a neurological disorder with epilepsy and prominent choreoathetosis caused by biallelic pathogenic variants in FRRS1L, which encodes an AMPA receptor outer-core protein. Loss of FRRS1L function attenuates AMPA-mediated currents, implicating chronic abnormalities of glutamatergic neurotransmission in this monogenic neurological disease of childhood. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  9. 18F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers

    Science.gov (United States)

    Puschmann, Andreas; Schöll, Michael; Ohlsson, Tomas; van Swieten, John; Honer, Michael; Englund, Elisabet

    2016-01-01

    Abstract Tau positron emission tomography ligands provide the novel possibility to image tau pathology in vivo. However, little is known about how in vivo brain uptake of tau positron emission tomography ligands relates to tau aggregates observed post-mortem. We performed tau positron emission tomography imaging with 18F-AV-1451 in three patients harbouring a p.R406W mutation in the MAPT gene, encoding tau. This mutation results in 3- and 4-repeat tau aggregates similar to those in Alzheimer’s disease, and many of the mutation carriers initially suffer from memory impairment and temporal lobe atrophy. Two patients with short disease duration and isolated memory impairment exhibited 18F-AV-1451 uptake mainly in the hippocampus and adjacent temporal lobe regions, correlating with glucose hypometabolism in corresponding regions. One patient died after 26 years of disease duration with dementia and behavioural deficits. Pre-mortem, there was 18F-AV-1451 uptake in the temporal and frontal lobes, as well as in the basal ganglia, which strongly correlated with the regional extent and amount of tau pathology in post-mortem brain sections. Amyloid-β (18F-flutemetamol) positron emission tomography scans were negative in all cases, as were stainings of brain sections for amyloid. This provides strong evidence that 18F-AV-1451 positron emission tomography can be used to accurately quantify in vivo the regional distribution of hyperphosphorylated tau protein. PMID:27357347

  10. Associations of filaggrin gene loss-of-function variants and human papillomavirus-related cancer and pre-cancer in Danish adults.

    Directory of Open Access Journals (Sweden)

    Tea Skaaby

    Full Text Available Filaggrin proteins are expressed in the skin, oral cavity, oesophagus, and cervical mucose. Loss-of-function mutations in the filaggrin gene (FLG reduce filaggrin expression and cause an impaired skin barrier function. We hypothesized that FLG mutation carriers would be more susceptible to human papillomavirus (HPV infection and thus a higher risk of HPV-related cancer and pre-cancer. We investigated the association of the FLG genotype with incidence of HPV-related cancer of cervix, vagina, vulva, penis, anus and head and neck, and pre-cancer of the cervix.We included 13,376 persons from four population-based studies conducted in the same background population in Copenhagen, Denmark. Participants were genotyped for the most common FLG mutations in Europeans. Information on cancer was obtained from The Danish Cancer Registry until 11 July 2011.There were 489 cases of prevalent and 97 cases of incident HPV-related cancer and pre-cancer (median follow-up 11.5 years. There was a statistically significant association between FLG genotype and incident HPV-related cancer and pre-cancer with a hazard ratio, HR = 2.1 (95% confidence intervals, CI: 1.2, 3.7 for FLG mutation carriers vs. wild types.FLG loss-of-function mutations were associated with higher incidence of HPV-related cancers and pre-cancers that are potentially screening and vaccine preventable.

  11. The diagnostic and therapeutic aspects of loss-of-function cardiac sodium channelopathies in children

    NARCIS (Netherlands)

    Chockalingam, Priya; Clur, Sally-Ann B.; Breur, Johannes M. P. J.; Kriebel, Thomas; Paul, Thomas; Rammeloo, Lukas A.; Wilde, Arthur A. M.; Blom, Nico A.

    2012-01-01

    BACKGROUND Loss-of-function sodium channelopathies manifest as a spectrum of diseases including Brugada syndrome (BrS) and cardiac conduction disease. OBJECTIVE To analyze the diagnostic and therapeutic aspects of these disorders in children. METHODS Patients aged <= 16 years with genetically

  12. A systematic survey of loss-of-function variants in human protein-coding genes

    NARCIS (Netherlands)

    MacArthur, D.G.; Balasubramanian, S.; Frankish, A.; Huang, N.; Morris, J.; Walter, K.; Jostins, L.; Habegger, L.; Pickrell, J.K.; Montgomery, S.B.; Albers, C.A.; Zhang, Z.D.; Conrad, D.F.; Lunter, G.; Zheng, H.; Ayub, Q.; DePristo, M.A.; Banks, E.; Hu, M.; Handsaker, R.E.; Rosenfeld, J.A.; Fromer, M.; Jin, M.; Mu, X.J.; Khurana, E.; Ye, K.; Kay, M.; Saunders, G.I.; Suner, M.M.; Hunt, T.; Barnes, I.H.; Amid, C.; Carvalho-Silva, D.R.; Bignell, A.H.; Snow, C.; Yngvadottir, B.; Bumpstead, S.; Cooper, D.N.; Xue, Y.; Romero, I.G.; Genomes Project, C.; Wang, J; Li, Y.; Gibbs, R.A.; McCarroll, S.A.; Dermitzakis, E.T.; Pritchard, J.K.; Barrett, J.C.; Harrow, J.; Hurles, M.E.; Gerstein, M.B.; Tyler-Smith, C.

    2012-01-01

    Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to

  13. A missense mutation in growth differentiation factor 9 (GDF9 is strongly associated with litter size in sheep

    Directory of Open Access Journals (Sweden)

    Våge Dag I

    2013-01-01

    Full Text Available Abstract Background A genome wide association study for litter size in Norwegian White Sheep (NWS was conducted using the recently developed ovine 50K SNP chip from Illumina. After genotyping 378 progeny tested artificial insemination (AI rams, a GWAS analysis was performed on estimated breeding values (EBVs for litter size. Results A QTL-region was identified on sheep chromosome 5, close to the growth differentiation factor 9 (GDF9, which is known to be a strong candidate gene for increased ovulation rate/litter size. Sequencing of the GDF9 coding region in the most extreme sires (high and low BLUP values revealed a single nucleotide polymorphism (c.1111G>A, responsible for a Val→Met substitution at position 371 (V371M. This polymorphism has previously been identified in Belclare and Cambridge sheep, but was not found to be associated with fertility. In our NWS-population the c.1111G>A SNP showed stronger association with litter size than any other single SNP on the Illumina 50K ovine SNP chip. Based on the estimated breeding values, daughters of AI rams homozygous for c.1111A will produce minimum 0.46 - 0.57 additional lambs compared to daughters of wild-type rams. Conclusion We have identified a missense mutation in the bioactive part of the GDF9 protein that shows strong association with litter size in NWS. Based on the NWS breeding history and the marked increase in the c.1111A allele frequency in the AI ram population since 1983, we hypothesize that c.1111A allele originate from Finnish landrace imported to Norway around 1970. Because of the widespread use of Finnish landrace and the fact that the ewes homozygous for the c.1111A allele are reported to be fertile, we expect the commercial impact of this mutation to be high.

  14. Effective RNAi-mediated β2-microglobulin loss of function by transgenesis in Xenopus laevis

    Directory of Open Access Journals (Sweden)

    Hristina Nedelkovska

    2013-01-01

    To impair MHC class I (class I function in vivo in the amphibian Xenopus, we developed an effective reverse genetic loss of function approach by combining I-SceI meganuclease-mediated transgenesis with RNAi technology. We generated transgenic outbred X. laevis and isogenetic laevis/gilli cloned lines with stably silenced expression of β2-microglobulin (b2m critical for class I function. Transgenic F1 frogs exhibited decreased surface class I expression on erythrocytes and lymphocytes, decreased frequency of peripheral CD8 T cells and impaired CD8 T cell-mediated skin allograft rejection. Additionally, b2m knockdown increased susceptibility to viral infection of F0 transgenic larvae. This loss of function strategy offers new avenues for studying ontogeny of immunity and other developmental processes in Xenopus.

  15. Loss-of-function variants in ADCY3 increase risk of obesity and type 2 diabetes

    DEFF Research Database (Denmark)

    Grarup, Niels; Moltke, Ida; Andersen, Mette K

    2018-01-01

    We have identified a variant in ADCY3 (encoding adenylate cyclase 3) associated with markedly increased risk of obesity and type 2 diabetes in the Greenlandic population. The variant disrupts a splice acceptor site, and carriers have decreased ADCY3 RNA expression. Additionally, we observe...... an enrichment of rare ADCY3 loss-of-function variants among individuals with type 2 diabetes in trans-ancestry cohorts. These findings provide new information on disease etiology relevant for future treatment strategies....

  16. Rapid Generation of Human Genetic Loss-of-Function iPSC Lines by Simultaneous Reprogramming and Gene Editing

    Directory of Open Access Journals (Sweden)

    Andrew M. Tidball

    2017-09-01

    Full Text Available Specifically ablating genes in human induced pluripotent stem cells (iPSCs allows for studies of gene function as well as disease mechanisms in disorders caused by loss-of-function (LOF mutations. While techniques exist for engineering such lines, we have developed and rigorously validated a method of simultaneous iPSC reprogramming while generating CRISPR/Cas9-dependent insertions/deletions (indels. This approach allows for the efficient and rapid formation of genetic LOF human disease cell models with isogenic controls. The rate of mutagenized lines was strikingly consistent across experiments targeting four different human epileptic encephalopathy genes and a metabolic enzyme-encoding gene, and was more efficient and consistent than using CRISPR gene editing of established iPSC lines. The ability of our streamlined method to reproducibly generate heterozygous and homozygous LOF iPSC lines with passage-matched isogenic controls in a single step provides for the rapid development of LOF disease models with ideal control lines, even in the absence of patient tissue.

  17. Gag mutations strongly contribute to HIV-1 resistance to protease inhibitors in highly drug-experienced patients besides compensating for fitness loss.

    Science.gov (United States)

    Dam, Elisabeth; Quercia, Romina; Glass, Bärbel; Descamps, Diane; Launay, Odile; Duval, Xavier; Kräusslich, Hans-Georg; Hance, Allan J; Clavel, François

    2009-03-01

    Human immunodeficiency virus type 1 (HIV-1) resistance to protease inhibitors (PI) results from mutations in the viral protease (PR) that reduce PI binding but also decrease viral replicative capacity (RC). Additional mutations compensating for the RC loss subsequently accumulate within PR and in Gag substrate cleavage sites. We examined the respective contribution of mutations in PR and Gag to PI resistance and RC and their interdependence using a panel of HIV-1 molecular clones carrying different sequences from six patients who had failed multiple lines of treatment. Mutations in Gag strongly and directly contributed to PI resistance besides compensating for fitness loss. This effect was essentially carried by the C-terminal region of Gag (containing NC-SP2-p6) with little or no contribution from MA, CA, and SP1. The effect of Gag on resistance depended on the presence of cleavage site mutations A431V or I437V in NC-SP2-p6 and correlated with processing of the NC/SP2 cleavage site. By contrast, reverting the A431V or I437V mutation in these highly evolved sequences had little effect on RC. Mutations in the NC-SP2-p6 region of Gag can be dually selected as compensatory and as direct PI resistance mutations, with cleavage at the NC-SP2 site behaving as a rate-limiting step in PI resistance. Further compensatory mutations render viral RC independent of the A431V or I437V mutations while their effect on resistance persists.

  18. Gag mutations strongly contribute to HIV-1 resistance to protease inhibitors in highly drug-experienced patients besides compensating for fitness loss.

    Directory of Open Access Journals (Sweden)

    Elisabeth Dam

    2009-03-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 resistance to protease inhibitors (PI results from mutations in the viral protease (PR that reduce PI binding but also decrease viral replicative capacity (RC. Additional mutations compensating for the RC loss subsequently accumulate within PR and in Gag substrate cleavage sites. We examined the respective contribution of mutations in PR and Gag to PI resistance and RC and their interdependence using a panel of HIV-1 molecular clones carrying different sequences from six patients who had failed multiple lines of treatment. Mutations in Gag strongly and directly contributed to PI resistance besides compensating for fitness loss. This effect was essentially carried by the C-terminal region of Gag (containing NC-SP2-p6 with little or no contribution from MA, CA, and SP1. The effect of Gag on resistance depended on the presence of cleavage site mutations A431V or I437V in NC-SP2-p6 and correlated with processing of the NC/SP2 cleavage site. By contrast, reverting the A431V or I437V mutation in these highly evolved sequences had little effect on RC. Mutations in the NC-SP2-p6 region of Gag can be dually selected as compensatory and as direct PI resistance mutations, with cleavage at the NC-SP2 site behaving as a rate-limiting step in PI resistance. Further compensatory mutations render viral RC independent of the A431V or I437V mutations while their effect on resistance persists.

  19. Generation of mice harbouring a conditional loss-of-function allele of Gata6

    Directory of Open Access Journals (Sweden)

    Duncan Stephen A

    2006-04-01

    Full Text Available Abstract The zinc finger transcription factor GATA6 is believed to have important roles in the development of several organs including the liver, gastrointestinal tract and heart. However, analyses of the contribution of GATA6 toward organogenesis have been hampered because Gata6-/- mice fail to develop beyond gastrulation due to defects in extraembryonic endoderm function. We have therefore generated a mouse line harbouring a conditional loss-of-function allele of Gata6 using Cre/loxP technology. LoxP elements were introduced into introns flanking exon 2 of the Gata6 gene by homologous recombination in ES cells. Mice containing this altered allele were bred to homozygosity and were found to be viable and fertile. To assess the functional integrity of the loxP sites and to confirm that we had generated a Gata6 loss-of-function allele, we bred Gata6 'floxed' mice to EIIa-Cre mice in which Cre is ubiquitously expressed, and to Villin-Cre mice that express Cre in the epithelial cells of the intestine. We conclude that we have generated a line of mice in which GATA6 activity can be ablated in a cell type specific manner by expression of Cre recombinase. This line of mice can be used to establish the role of GATA6 in regulating embryonic development and various aspects of mammalian physiology.

  20. Structural implications of mutations in the pea SYM8 symbiosis gene, the DMI1 ortholog, encoding a predicted ion channel

    DEFF Research Database (Denmark)

    Edwards, Anne; Heckmann, Anne Birgitte Lau; Yousafzai, Faridoon

    2007-01-01

    the aspartate to valine and identified a missense mutation (changing alanine to valine adjacent to the aspartate residues) in this predicted filter region; both mutations caused a loss of function. We also identified a loss-of-function missense mutation (changing arginine to isoleucine) in a domain proposed...

  1. Loss of function in Mlo orthologs reduces susceptibility of pepper and tomato to powdery mildew disease caused by Leveillula taurica.

    Directory of Open Access Journals (Sweden)

    Zheng Zheng

    Full Text Available Powdery mildew disease caused by Leveillula taurica is a serious fungal threat to greenhouse tomato and pepper production. In contrast to most powdery mildew species which are epiphytic, L. taurica is an endophytic fungus colonizing the mesophyll tissues of the leaf. In barley, Arabidopsis, tomato and pea, the correct functioning of specific homologues of the plant Mlo gene family has been found to be required for pathogenesis of epiphytic powdery mildew fungi. The aim of this study was to investigate the involvement of the Mlo genes in susceptibility to the endophytic fungus L. taurica. In tomato (Solanum lycopersicum, a loss-of-function mutation in the SlMlo1 gene results in resistance to powdery mildew disease caused by Oidium neolycopersici. When the tomato Slmlo1 mutant was inoculated with L. taurica in this study, it proved to be less susceptible compared to the control, S. lycopersicum cv. Moneymaker. Further, overexpression of SlMlo1 in the tomato Slmlo1 mutant enhanced susceptibility to L. taurica. In pepper, the CaMlo2 gene was isolated by applying a homology-based cloning approach. Compared to the previously identified CaMlo1 gene, the CaMlo2 gene is more similar to SlMlo1 as shown by phylogenetic analysis, and the expression of CaMlo2 is up-regulated at an earlier time point upon L. taurica infection. However, results of virus-induced gene silencing suggest that both CaMlo1 and CaMlo2 may be involved in the susceptibility of pepper to L. taurica. The fact that overexpression of CaMlo2 restored the susceptibility of the tomato Slmlo1 mutant to O. neolycopersici and increased its susceptibility to L. taurica confirmed the role of CaMlo2 acting as a susceptibility factor to different powdery mildews, though the role of CaMlo1 as a co-factor for susceptibility cannot be excluded.

  2. Immunological loss-of-function due to genetic gain-of-function in humans: autosomal dominance of the third kind.

    Science.gov (United States)

    Boisson, Bertrand; Quartier, Pierre; Casanova, Jean-Laurent

    2015-02-01

    All the human primary immunodeficiencies (PIDs) recognized as such in the 1950s were Mendelian traits and, whether autosomal or X-linked, displayed recessive inheritance. The first autosomal dominant (AD) PID, hereditary angioedema, was recognized in 1963. However, since the first identification of autosomal recessive (AR), X-linked recessive (XR) and AD PID-causing genes in 1985 (ADA; severe combined immunodeficiency), 1986 (CYBB, chronic granulomatous disease) and 1989 (SERPING1; hereditary angioedema), respectively, the number of genetically defined AD PIDs has increased more rapidly than that of any other type of PID. AD PIDs now account for 61 of the 260 known conditions (23%). All known AR PIDs are caused by alleles with some loss-of-function (LOF). A single XR PID is caused by gain-of-function (GOF) mutations (WASP-related neutropenia, 2001). In contrast, only 44 of 61 AD defects are caused by LOF alleles, which exert dominance by haploinsufficiency or negative dominance. Since 2003, up to 17 AD disorders of the third kind, due to GOF alleles, have been described. Remarkably, six of the 17 genes concerned also harbor monoallelic (STAT3), biallelic (C3, CFB, CARD11, PIK3R1) or both monoallelic and biallelic (STAT1) LOF alleles in patients with other clinical phenotypes. Most heterozygous GOF alleles result in auto-inflammation, auto-immunity, or both, with a wide range of immunological and clinical forms. Some also underlie infections and, fewer, allergies, by impairing or enhancing immunity to non-self. Malignancies are also rare. The enormous diversity of immunological and clinical phenotypes is thought provoking and mirrors the diversity and pleiotropy of the underlying genotypes. These experiments of nature provide a unique insight into the quantitative regulation of human immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Exacerbated pulmonary arterial hypertension and right ventricular hypertrophy in animals with loss of function of extracellular superoxide dismutase.

    Science.gov (United States)

    Xu, Dachun; Guo, Haipeng; Xu, Xin; Lu, Zhongbing; Fassett, John; Hu, Xinli; Xu, Yawei; Tang, Qizhu; Hu, Dayi; Somani, Arif; Geurts, Aron M; Ostertag, Eric; Bache, Robert J; Weir, E Kenneth; Chen, Yingjie

    2011-08-01

    Studies have demonstrated that increased oxidative stress contributes to the pathogenesis and the development of pulmonary artery hypertension (PAH). Extracellular superoxide dismutase (SOD3) is essential for removing extracellular superoxide anions, and it is highly expressed in lung tissue. However, it is not clear whether endogenous SOD3 can influence the development of PAH. Here we examined the effect of SOD3 knockout on hypoxia-induced PAH in mice and a loss-of-function SOD3 gene mutation (SOD3(E124D)) on monocrotaline (40 mg/kg)-induced PAH in rats. SOD3 knockout significantly exacerbated 2 weeks of hypoxia-induced right ventricular (RV) pressure and RV hypertrophy, whereas RV pressure in SOD3 knockout mice under normoxic conditions is similar to wild-type controls. In untreated control rats at age of 8 weeks, there was no significant difference between wild-type and SOD3(E124D) rats in RV pressure and the ratio of RV weight:left ventricular weight (0.25±0.02 in wild-type rats versus 0.25±0.01 in SOD3(E124D) rats). However, monocrotaline caused significantly greater increases of RV pressure in SOD3(E124D) rats (48.6±1.8 mm Hg in wild-type versus 57.5±3.1 mm Hg in SOD3(E124D) rats), of the ratio of RV weight:left ventricular weight (0.41±0.01 versus 0.50±0.09; Prats (55.2±2.3% versus 69.9±2.6%; P<0.05). Together, these findings indicate that the endogenous SOD3 has no role in the development of PAH under control conditions but plays an important role in protecting the lung from the development of PAH under stress conditions.

  4. Distribution and medical impact of loss-of-function variants in the Finnish founder population.

    Directory of Open Access Journals (Sweden)

    Elaine T Lim

    2014-07-01

    Full Text Available Exome sequencing studies in complex diseases are challenged by the allelic heterogeneity, large number and modest effect sizes of associated variants on disease risk and the presence of large numbers of neutral variants, even in phenotypically relevant genes. Isolated populations with recent bottlenecks offer advantages for studying rare variants in complex diseases as they have deleterious variants that are present at higher frequencies as well as a substantial reduction in rare neutral variation. To explore the potential of the Finnish founder population for studying low-frequency (0.5-5% variants in complex diseases, we compared exome sequence data on 3,000 Finns to the same number of non-Finnish Europeans and discovered that, despite having fewer variable sites overall, the average Finn has more low-frequency loss-of-function variants and complete gene knockouts. We then used several well-characterized Finnish population cohorts to study the phenotypic effects of 83 enriched loss-of-function variants across 60 phenotypes in 36,262 Finns. Using a deep set of quantitative traits collected on these cohorts, we show 5 associations (p<5×10⁻⁸ including splice variants in LPA that lowered plasma lipoprotein(a levels (P = 1.5×10⁻¹¹⁷. Through accessing the national medical records of these participants, we evaluate the LPA finding via Mendelian randomization and confirm that these splice variants confer protection from cardiovascular disease (OR = 0.84, P = 3×10⁻⁴, demonstrating for the first time the correlation between very low levels of LPA in humans with potential therapeutic implications for cardiovascular diseases. More generally, this study articulates substantial advantages for studying the role of rare variation in complex phenotypes in founder populations like the Finns and by combining a unique population genetic history with data from large population cohorts and centralized research access to National Health

  5. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or 'classical' congenital myopathy

    NARCIS (Netherlands)

    Zaharieva, I.T.; Thor, M.G.; Oates, E.C.; Karnebeek, C. van; Hendson, G.; Blom, E.; Witting, N.; Rasmussen, M.; Gabbett, M.T.; Ravenscroft, G.; Sframeli, M.; Suetterlin, K.; Sarkozy, A.; D'Argenzio, L.; Hartley, L.; Matthews, E.; Pitt, M.; Vissing, J.; Ballegaard, M.; Krarup, C.; Slordahl, A.; Halvorsen, H.; Ye, X.C.; Zhang, L.H.; Lokken, N.; Werlauff, U.; Abdelsayed, M.; Davis, M.R.; Feng, L.; Phadke, R.; Sewry, C.A.; Morgan, J.E.; Laing, N.G.; Vallance, H.; Ruben, P.; Hanna, M.G.; Lewis, S.; Kamsteeg, E.J.; Mannikko, R.; Muntoni, F.

    2016-01-01

    See Cannon (doi:10.1093/brain/awv400) for a scientific commentary on this article.Congenital myopathies are a clinically and genetically heterogeneous group of muscle disorders characterized by congenital or early-onset hypotonia and muscle weakness, and specific pathological features on muscle

  6. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or 'classical' congenital myopathy

    DEFF Research Database (Denmark)

    Zaharieva, Irina T; Thor, Michael G; Oates, Emily C

    2016-01-01

    Congenital myopathies are a clinically and genetically heterogeneous group of muscle disorders characterized by congenital or early-onset hypotonia and muscle weakness, and specific pathological features on muscle biopsy. The phenotype ranges from foetal akinesia resulting in in utero or neonatal...

  7. A Zebrafish Loss-of-Function Model for Human CFAP53 Mutations Reveals Its Specific Role in Laterality Organ Function

    NARCIS (Netherlands)

    Noël, Emily S; Momenah, Tarek S; Al-Dagriri, Khalid; Al-Suwaid, Abdulrahman; Al-Shahrani, Safar; Jiang, Hui; Willekers, Sven; Oostveen, Yara Y; Chocron, Sonja; Postma, Alex V; Bhuiyan, Zahurul A; Bakkers, Jeroen

    Establishing correct left-right asymmetry during embryonic development is crucial for proper asymmetric positioning of the organs. Congenital heart defects, such as dextrocardia, transposition of the arteries, and inflow or outflow tract malformations, comprise some of the most common birth defects

  8. A Zebrafish Loss-of-Function Model for Human CFAP53 Mutations Reveals Its Specific Role in Laterality Organ Function

    NARCIS (Netherlands)

    Noël, Emily S.; Momenah, Tarek S.; Al-Dagriri, Khalid; Al-Suwaid, Abdulrahman; Al-Shahrani, Safar; Jiang, Hui; Willekers, Sven; Oostveen, Yara Y.; Chocron, Sonja; Postma, Alex V.; Bhuiyan, Zahurul A.; Bakkers, Jeroen

    2016-01-01

    Establishing correct left-right asymmetry during embryonic development is crucial for proper asymmetric positioning of the organs. Congenital heart defects, such as dextrocardia, transposition of the arteries, and inflow or outflow tract malformations, comprise some of the most common birth defects

  9. A zebrafish Loss-of-Function Model for Human CFAP53 Mutations Reveals its Specific Role in Laterality Organ Function

    NARCIS (Netherlands)

    Noël, Emily S; Momenah, Tarek S; Al-Dagriri, Khalid; Al-Suwaid, Abdulrahman; Al-Shahrani, Safar; Jiang, Hui; Willekers, Sven; Oostveen, Yara Y; Chocron, Sonja; Postma, Alex V; Bhuiyan, Zahurul A; Bakkers, Jeroen

    Establishing correct left-right asymmetry during embryonic development is crucial for proper asymmetric positioning of the organs. Congenital heart defects such as dextrocardia, transposition of the arteries, and inflow or outflow tract malformations, comprise some of the most common birth defects

  10. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma

    DEFF Research Database (Denmark)

    Smith, Dirk; Helgason, Hannes; Sulem, Patrick

    2017-01-01

    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole-g...

  11. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma

    OpenAIRE

    Smith, Dirk; Helgason, Hannes; Sulem, Patrick; Bjornsdottir, Unnur Steina; Lim, Ai Ching; Sveinbjornsson, Gardar; Hasegawa, Haruki; Brown, Michael; Ketchem, Randal R.; Gavala, Monica; Garrett, Logan; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sigurdsson, Asgeir; Magnusson, Olafur T.

    2017-01-01

    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole-genome sequencing and imputation into the Icelandic population, we found a rare variant in IL33 (NM_ 001199640: exon7: c.487-1G> C(rs146597587- C), allele frequency = 0.65%) that disrupts a canonical s...

  12. A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma

    NARCIS (Netherlands)

    Smith, Dirk; Helgason, Hannes; Sulem, Patrick; Bjornsdottir, Unnur Steina; Lim, Ai Ching; Sveinbjornsson, Gardar; Hasegawa, Haruki; Brown, Michael; Ketchem, Randal R.; Gavala, Monica; Garrett, Logan; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sigurdsson, Asgeir; Magnusson, Olafur T.; Eyjolfsson, Gudmundur I.; Olafsson, Isleifur; Onundarson, Pall Torfi; Sigurdardottir, Olof; Gislason, David; Gislason, Thorarinn; Ludviksson, Bjorn Runar; Ludviksdottir, Dora; Boezen, H. Marike; Heinzmann, Andrea; Krueger, Marcus; Porsbjerg, Celeste; Ahluwalia, Tarunveer S.; Waage, Johannes; Backer, Vibeke; Deichmann, Klaus A.; Koppelman, Gerard H.; Bonnelykke, Klaus; Bisgaard, Hans; Masson, Gisli; Thorsteinsdottir, Unnur; Gudbjartsson, Daniel F.; Johnston, James A.; Jonsdottir, Ingileif; Stefansson, Kari

    2017-01-01

    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through

  13. Loss-of-Function CNKSR2 Mutation Is a Likely Cause of Non-Syndromic X-Linked Intellectual Disability.

    Science.gov (United States)

    Houge, G; Rasmussen, I H; Hovland, R

    2012-01-01

    In a non-dysmorphic 5-year-old boy with developmental delay, well-controlled epilepsy, and microcephaly, a 234-kb deletion of Xp22.12 was detected by copy number analysis. The maternally inherited deletion removed the initial 15 of the 21 exons of the connector enhancer of KSR-2 gene called CNKSR2 or CNK2. Our finding suggests that loss of CNKSR2 is a novel cause of non-syndromic X-linked mental retardation, an assumption supported by high gene expression in the brain, localization to the post-synaptic density, and a role in RAS/MAPK-dependent signal transduction.

  14. Loss-of-Function CNKSR2 Mutation Is a Likely Cause of Non-Syndromic X-Linked Intellectual Disability

    OpenAIRE

    Houge, G.; Rasmussen, I.H.; Hovland, R.

    2011-01-01

    In a non-dysmorphic 5-year-old boy with developmental delay, well-controlled epilepsy, and microcephaly, a 234-kb deletion of Xp22.12 was detected by copy number analysis. The maternally inherited deletion removed the initial 15 of the 21 exons of the connector enhancer of KSR-2 gene called CNKSR2 or CNK2. Our finding suggests that loss of CNKSR2 is a novel cause of non-syndromic X-linked mental retardation, an assumption supported by high gene expression in the brain, localization to the pos...

  15. Associations of Filaggrin Gene Loss-of-Function Variants with Urinary Phthalate Metabolites and Testicular Function in Young Danish Men

    DEFF Research Database (Denmark)

    Joensen, Ulla Nordström; Jørgensen, Niels; Meldgaard, Michael

    2014-01-01

    variants in a cross-sectional study of 861 young men from the general Danish population. METHODS: All men were genotyped for FLG R501X, 2282del4, and R2447X loss-of-function variants. We measured urinary concentrations of 14 phthalate metabolites and serum levels of reproductive hormones. We also evaluated...... not significantly associated with reproductive hormones or semen quality parameters. CONCLUSION: This study provides evidence that carriers of FLG loss-of-function alleles may have higher internal exposure to phthalates, possibly due to increased transepidermal absorption. FLG loss-of-function variants may indicate......BACKGROUND: Filaggrin is an epidermal protein that is crucial for skin barrier function. Up to 10% of Europeans and 5% of Asians carry at least one null allele in the filaggrin gene (FLG). Reduced expression of filaggrin in carriers of the null allele is associated with facilitated transfer...

  16. Biallelic loss-of-function variants in DOCK3 cause muscle hypotonia, ataxia, and intellectual disability.

    Science.gov (United States)

    Helbig, K L; Mroske, C; Moorthy, D; Sajan, S A; Velinov, M

    2017-10-01

    DOCK3 encodes the dedicator of cytokinesis 3 protein, a member of the DOCK180 family of proteins that are characterized by guanine-nucleotide exchange factor activity. DOCK3 is expressed exclusively in the central nervous system and plays an important role in axonal outgrowth and cytoskeleton reorganization. Dock3 knockout mice exhibit motor deficiencies with abnormal ataxic gait and impaired learning. We report 2 siblings with biallelic loss-of-function variants in DOCK3. Diagnostic whole-exome sequencing (WES) and chromosomal microarray were performed on a proband with severe developmental disability, hypotonia, and ataxic gait. Testing was also performed on the proband's similarly affected brother. A paternally inherited 458 kb deletion in chromosomal region 3p21.2 disrupting the DOCK3 gene was identified in both affected siblings. WES identified a nonsense variant c.382C>G (p.Gln128*) in the DOCK3 gene (NM_004947) on the maternal allele in both siblings. Common features in both affected individuals include severe developmental disability, ataxic gait, and severe hypotonia, which recapitulates the Dock3 knockout mouse phenotype. We show that complete DOCK3 deficiency in humans leads to developmental disability with significant hypotonia and gait ataxia, probably due to abnormal axonal development. © 2017 The Authors. Clinical Genetics published by John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Sodium channelopathies of skeletal muscle result from gain or loss of function

    OpenAIRE

    Jurkat-Rott, Karin; Holzherr, Boris; Fauler, Michael; Lehmann-Horn, Frank

    2010-01-01

    Five hereditary sodium channelopathies of skeletal muscle have been identified. Prominent symptoms are either myotonia or weakness caused by an increase or decrease of muscle fiber excitability. The voltage-gated sodium channel NaV1.4, initiator of the muscle action potential, is mutated in all five disorders. Pathogenetically, both loss and gain of function mutations have been described, the latter being the more frequent mechanism and involving not just the ion-conducting pore, but aberrant...

  18. Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in Commensal Gut Bacteria.

    Science.gov (United States)

    Sousa, Ana; Ramiro, Ricardo S; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, Isabel

    2017-11-01

    The evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) spread to >90% frequency in all colonized mice. Here, we show that this loss-of-function is repeatedly reversed when a gat-negative clone colonizes new mice. The regain of function occurs via compensatory mutation and reversion, the latter leaving no trace of past adaptation. We further show that loss-of-function adaptive mutants reevolve, after colonization with an evolved gat-positive clone. Thus, even under strong bottlenecks a regime of strong-mutation-strong-selection dominates adaptation. Coupling experiments and modeling, we establish that reverse evolution recurrently generates two coexisting phenotypes within the microbiota that can or not consume galactitol (gat-positive and gat-negative, respectively). Although the abundance of the dominant strain, the gat-negative, depends on the microbiota composition, gat-positive abundance is independent of the microbiota composition and can be precisely manipulated by supplementing the diet with galactitol. These results show that a specific diet is able to change the abundance of specific strains. Importantly, we find polymorphism for these phenotypes in indigenous Enterobacteria of mice and man. Our results demonstrate that natural selection can greatly overwhelm genetic drift at structuring the strain diversity of gut commensals and that competition for limiting resources may be a key mechanism for maintaining polymorphism in the gut. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  19. A comprehensive dataset of genes with a loss-of-function mutant phenotype in Arabidopsis.

    Science.gov (United States)

    Lloyd, Johnny; Meinke, David

    2012-03-01

    Despite the widespread use of Arabidopsis (Arabidopsis thaliana) as a model plant, a curated dataset of Arabidopsis genes with mutant phenotypes remains to be established. A preliminary list published nine years ago in Plant Physiology is outdated, and genome-wide phenotype information remains difficult to obtain. We describe here a comprehensive dataset of 2,400 genes with a loss-of-function mutant phenotype in Arabidopsis. Phenotype descriptions were gathered primarily from manual curation of the scientific literature. Genes were placed into prioritized groups (essential, morphological, cellular-biochemical, and conditional) based on the documented phenotypes of putative knockout alleles. Phenotype classes (e.g. vegetative, reproductive, and timing, for the morphological group) and subsets (e.g. flowering time, senescence, circadian rhythms, and miscellaneous, for the timing class) were also established. Gene identities were classified as confirmed (through molecular complementation or multiple alleles) or not confirmed. Relationships between mutant phenotype and protein function, genetic redundancy, protein connectivity, and subcellular protein localization were explored. A complementary dataset of 401 genes that exhibit a mutant phenotype only when disrupted in combination with a putative paralog was also compiled. The importance of these genes in confirming functional redundancy and enhancing the value of single gene datasets is discussed. With further input and curation from the Arabidopsis community, these datasets should help to address a variety of important biological questions, provide a foundation for exploring the relationship between genotype and phenotype in angiosperms, enhance the utility of Arabidopsis as a reference plant, and facilitate comparative studies with model genetic organisms.

  20. Detecting low frequent loss-of-function alleles in genome wide association studies with red hair color as example

    NARCIS (Netherlands)

    F. Liu (Fan); M.V. Struchalin (Maksim); K. van Duijn (Kate); A. Hofman (Albert); A.G. Uitterlinden (André); Y.S. Aulchenko (Yurii); M.H. Kayser (Manfred)

    2011-01-01

    textabstractMultiple loss-of-function (LOF) alleles at the same gene may influence a phenotype not only in the homozygote state when alleles are considered individually, but also in the compound heterozygote (CH) state. Such LOF alleles typically have low frequencies and moderate to large effects.

  1. Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis

    DEFF Research Database (Denmark)

    Palmer, Colin N A; Irvine, Alan D; Terron-Kwiatkowski, Ana

    2006-01-01

    most genetic studies have focused on immunological mechanisms, a primary epithelial barrier defect has been anticipated. Filaggrin is a key protein that facilitates terminal differentiation of the epidermis and formation of the skin barrier. Here we show that two independent loss-of-function genetic...... dermatitis. This work establishes a key role for impaired skin barrier function in the development of atopic disease....

  2. Sodium channelopathies of skeletal muscle result from gain or loss of function

    Science.gov (United States)

    Jurkat-Rott, Karin; Holzherr, Boris; Fauler, Michael

    2010-01-01

    Five hereditary sodium channelopathies of skeletal muscle have been identified. Prominent symptoms are either myotonia or weakness caused by an increase or decrease of muscle fiber excitability. The voltage-gated sodium channel NaV1.4, initiator of the muscle action potential, is mutated in all five disorders. Pathogenetically, both loss and gain of function mutations have been described, the latter being the more frequent mechanism and involving not just the ion-conducting pore, but aberrant pores as well. The type of channel malfunction is decisive for therapy which consists either of exerting a direct effect on the sodium channel, i.e., by blocking the pore, or of restoring skeletal muscle membrane potential to reduce the fraction of inactivated channels. PMID:20237798

  3. Enu mutagenesis identifies a novel platelet phenotype in a loss-of-function Jak2 allele.

    Directory of Open Access Journals (Sweden)

    Nicole M Anderson

    Full Text Available Utilizing ENU mutagenesis, we identified a mutant mouse with elevated platelets. Genetic mapping localized the mutation to an interval on chromosome 19 that encodes the Jak2 tyrosine kinase. We identified a A3056T mutation resulting in a premature stop codon within exon 19 of Jak2 (Jak2(K915X, resulting in a protein truncation and functionally inactive enzyme. This novel platelet phenotype was also observed in mice bearing a hemizygous targeted disruption of the Jak2 locus (Jak2(+/-. Timed pregnancy experiments revealed that Jak2(K915X/K915X and Jak2(-/- displayed embryonic lethality; however, Jak2(K915X/K915X embryos were viable an additional two days compared to Jak2(-/- embryos. Our data suggest that perturbing JAK2 activation may have unexpected consequences in elevation of platelet number and correspondingly, important implications for treatment of hematological disorders with constitutive Jak2 activity.

  4. Sodium channelopathies of skeletal muscle result from gain or loss of function.

    Science.gov (United States)

    Jurkat-Rott, Karin; Holzherr, Boris; Fauler, Michael; Lehmann-Horn, Frank

    2010-07-01

    Five hereditary sodium channelopathies of skeletal muscle have been identified. Prominent symptoms are either myotonia or weakness caused by an increase or decrease of muscle fiber excitability. The voltage-gated sodium channel NaV1.4, initiator of the muscle action potential, is mutated in all five disorders. Pathogenetically, both loss and gain of function mutations have been described, the latter being the more frequent mechanism and involving not just the ion-conducting pore, but aberrant pores as well. The type of channel malfunction is decisive for therapy which consists either of exerting a direct effect on the sodium channel, i.e., by blocking the pore, or of restoring skeletal muscle membrane potential to reduce the fraction of inactivated channels.

  5. Loss of Function of Evc2 in Dental Mesenchyme Leads to Hypomorphic Enamel.

    Science.gov (United States)

    Zhang, H; Takeda, H; Tsuji, T; Kamiya, N; Kunieda, T; Mochida, Y; Mishina, Y

    2017-04-01

    Ellis-van Creveld (EvC) syndrome is an autosomal-recessive skeletal dysplasia, characterized by short stature and postaxial polydactyly. A series of dental abnormalities, including hypomorphic enamel formation, has been reported in patients with EvC. Despite previous studies that attempted to uncover the mechanism leading to abnormal tooth development, little is known regarding how hypomorphic enamel is formed in patients with EvC. In the current study, using Evc2/ Limbin mutant mice we recently generated, we analyzed enamel formation in the mouse incisor. Consistent with symptoms in human patients, we observed that Evc2 mutant mice had smaller incisors with enamel hypoplasia. Histologic observations coupled with ameloblast marker analyses suggested that Evc2 mutant preameloblasts were capable of differentiating to secretory ameloblasts; this process, however, was apparently delayed, due to delayed odontoblast differentiation, mediated by a limited number of dental mesenchymal stem cells in Evc2 mutant mice. This concept was further supported by the observation that dental mesenchymal-specific deletion of Evc2 phenocopied the tooth abnormalities in Evc2 mutants. Overall, our findings suggest that mutations in Evc2 affect dental mesenchymal stem cell homeostasis, which further leads to hypomorphic enamel formation.

  6. A loss of function analysis of host factors influencing Vaccinia virus replication by RNA interference.

    Directory of Open Access Journals (Sweden)

    Philippa M Beard

    Full Text Available Vaccinia virus (VACV is a large, cytoplasmic, double-stranded DNA virus that requires complex interactions with host proteins in order to replicate. To explore these interactions a functional high throughput small interfering RNA (siRNA screen targeting 6719 druggable cellular genes was undertaken to identify host factors (HF influencing the replication and spread of an eGFP-tagged VACV. The experimental design incorporated a low multiplicity of infection, thereby enhancing detection of cellular proteins involved in cell-to-cell spread of VACV. The screen revealed 153 pro- and 149 anti-viral HFs that strongly influenced VACV replication. These HFs were investigated further by comparisons with transcriptional profiling data sets and HFs identified in RNAi screens of other viruses. In addition, functional and pathway analysis of the entire screen was carried out to highlight cellular mechanisms involved in VACV replication. This revealed, as anticipated, that many pro-viral HFs are involved in translation of mRNA and, unexpectedly, suggested that a range of proteins involved in cellular transcriptional processes and several DNA repair pathways possess anti-viral activity. Multiple components of the AMPK complex were found to act as pro-viral HFs, while several septins, a group of highly conserved GTP binding proteins with a role in sequestering intracellular bacteria, were identified as strong anti-viral VACV HFs. This screen has identified novel and previously unexplored roles for cellular factors in poxvirus replication. This advancement in our understanding of the VACV life cycle provides a reliable knowledge base for the improvement of poxvirus-based vaccine vectors and development of anti-viral theraputics.

  7. In Vivo Modelling of ATP1A3 G316S-Induced Ataxia in C. elegans Using CRISPR/Cas9-Mediated Homologous Recombination Reveals Dominant Loss of Function Defects.

    Directory of Open Access Journals (Sweden)

    Altar Sorkaç

    Full Text Available The NIH Undiagnosed Diseases Program admitted a male patient with unclassifiable late-onset ataxia-like symptoms. Exome sequencing revealed a heterozygous de novo mutation converting glycine 316 to serine in ATP1A3, which might cause disease. ATP1A3 encodes the Na+/K+ ATPase pump α3-subunit. Using CRISPR/Cas9-mediated homologous recombination for genome editing, we modelled this putative disease-causing allele in Caenorhabditis elegans, recreating the patient amino acid change in eat-6, the orthologue of ATP1A3. The impact of the mutation on eat-6 function at the neuromuscular junction was examined using two behavioural assays: rate of pharyngeal pumping and sensitivity to aldicarb, a drug that causes paralysis over time via the inhibition of acetylcholinesterase. The patient allele decreased pumping rates and caused hypersensitivity to aldicarb. Animals heterozygous for the allele exhibited similar defects, whereas loss of function mutations in eat-6 were recessive. These results indicate that the mutation is dominant and impairs the neuromuscular function. Thus, we conclude that the de novo G316S mutation in ATP1A3 likely causes or contributes to patient symptoms. More broadly, we conclude that, for conserved genes, it is possible to rapidly and easily model human diseases in C. elegans using CRIPSR/Cas9 genome editing.

  8. Duplication and Loss of Function of Genes Encoding RNA Polymerase III Subunit C4 Causes Hybrid Incompatibility in Rice

    Directory of Open Access Journals (Sweden)

    Giao Ngoc Nguyen

    2017-08-01

    Full Text Available Reproductive barriers are commonly observed in both animals and plants, in which they maintain species integrity and contribute to speciation. This report shows that a combination of loss-of-function alleles at two duplicated loci, DUPLICATED GAMETOPHYTIC STERILITY 1 (DGS1 on chromosome 4 and DGS2 on chromosome 7, causes pollen sterility in hybrid progeny derived from an interspecific cross between cultivated rice, Oryza sativa, and an Asian annual wild rice, O. nivara. Male gametes carrying the DGS1 allele from O. nivara (DGS1-nivaras and the DGS2 allele from O. sativa (DGS2-T65s were sterile, but female gametes carrying the same genotype were fertile. We isolated the causal gene, which encodes a protein homologous to DNA-dependent RNA polymerase (RNAP III subunit C4 (RPC4. RPC4 facilitates the transcription of 5S rRNAs and tRNAs. The loss-of-function alleles at DGS1-nivaras and DGS2-T65s were caused by weak or nonexpression of RPC4 and an absence of RPC4, respectively. Phylogenetic analysis demonstrated that gene duplication of RPC4 at DGS1 and DGS2 was a recent event that occurred after divergence of the ancestral population of Oryza from other Poaceae or during diversification of AA-genome species.

  9. Gag mutations strongly contribute to HIV-1 resistance to protease inhibitors in highly drug-experienced patients besides compensating for fitness loss.

    OpenAIRE

    Elisabeth Dam; Romina Quercia; Bärbel Glass; Diane Descamps; Odile Launay; Xavier Duval; Hans-Georg Kräusslich; Allan J Hance; François Clavel

    2009-01-01

    Human immunodeficiency virus type 1 (HIV-1) resistance to protease inhibitors (PI) results from mutations in the viral protease (PR) that reduce PI binding but also decrease viral replicative capacity (RC). Additional mutations compensating for the RC loss subsequently accumulate within PR and in Gag substrate cleavage sites. We examined the respective contribution of mutations in PR and Gag to PI resistance and RC and their interdependence using a panel of HIV-1 molecular clones carrying dif...

  10. Loss of functional diversity of ant assemblages in secondary tropical forests.

    Science.gov (United States)

    Bihn, Jochen H; Gebauer, Gerhard; Brandl, Roland

    2010-03-01

    Secondary forests and plantations increasingly dominate the tropical wooded landscape in place of primary forests. The expected reduction of biodiversity and its impact on ecological functions provided by these secondary forests are of major concern to society and ecologists. The potential effect of biodiversity loss on ecosystem functioning depends largely on the associated loss in the functional diversity of animal and plant assemblages, i.e., the degree of functional redundancy among species. However, the relationship between species and functional diversity is still poorly documented for most ecosystems. Here, we analyze how changes in the species diversity of ground-foraging ant assemblages translate into changes of functional diversity along a successional gradient of secondary forests in the Atlantic Forest of Brazil. Our analysis uses continuous measures of functional diversity and is based on four functional traits related to resource use of ants: body size, relative eye size, relative leg length, and trophic position. We find a strong relationship between species and functional diversity, independent of the functional traits used, with no evidence for saturation in this relationship. Recovery of species richness and diversity of ant assemblages in tropical secondary forests was accompanied by a proportional increase of functional richness and diversity of assemblages. Moreover, our results indicate that the increase in functional diversity along the successional gradient of secondary forests is primarily driven by rare species, which are functionally unique. The observed loss of both species and functional diversity in secondary forests offers no reason to believe that the ecological functions provided by secondary forests are buffered against species loss through functional redundancy.

  11. Sleep deprivation leads to a loss of functional connectivity in frontal brain regions.

    Science.gov (United States)

    Verweij, Ilse M; Romeijn, Nico; Smit, Dirk Ja; Piantoni, Giovanni; Van Someren, Eus Jw; van der Werf, Ysbrand D

    2014-07-19

    The restorative effect of sleep on waking brain activity remains poorly understood. Previous studies have compared overall neural network characteristics after normal sleep and sleep deprivation. To study whether sleep and sleep deprivation might differentially affect subsequent connectivity characteristics in different brain regions, we performed a within-subject study of resting state brain activity using the graph theory framework adapted for the individual electrode level.In balanced order, we obtained high-density resting state electroencephalography (EEG) in 8 healthy participants, during a day following normal sleep and during a day following total sleep deprivation. We computed topographical maps of graph theoretical parameters describing local clustering and path length characteristics from functional connectivity matrices, based on synchronization likelihood, in five different frequency bands. A non-parametric permutation analysis with cluster correction for multiple comparisons was applied to assess significance of topographical changes in clustering coefficient and path length. Significant changes in graph theoretical parameters were only found on the scalp overlying the prefrontal cortex, where the clustering coefficient (local integration) decreased in the alpha frequency band and the path length (global integration) increased in the theta frequency band. These changes occurred regardless, and independent of, changes in power due to the sleep deprivation procedure. The findings indicate that sleep deprivation most strongly affects the functional connectivity of prefrontal cortical areas. The findings extend those of previous studies, which showed sleep deprivation to predominantly affect functions mediated by the prefrontal cortex, such as working memory. Together, these findings suggest that the restorative effect of sleep is especially relevant for the maintenance of functional connectivity of prefrontal brain regions.

  12. Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

    Directory of Open Access Journals (Sweden)

    Vaishaali Natarajan

    Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

  13. Loss of Function of FATTY ACID DESATURASE7 in Tomato Enhances Basal Aphid Resistance in a Salicylate-Dependent Manner1[W][OA

    Science.gov (United States)

    Avila, Carlos A.; Arévalo-Soliz, Lirio M.; Jia, Lingling; Navarre, Duroy A.; Chen, Zhaorigetu; Howe, Gregg A.; Meng, Qing-Wei; Smith, Jonathon E.; Goggin, Fiona L.

    2012-01-01

    We report here that disruption of function of the ω-3 FATTY ACID DESATURASE7 (FAD7) enhances plant defenses against aphids. The suppressor of prosystemin-mediated responses2 (spr2) mutation in tomato (Solanum lycopersicum), which eliminates the function of FAD7, reduces the settling behavior, survival, and fecundity of the potato aphid (Macrosiphum euphorbiae). Likewise, the antisense suppression of LeFAD7 expression in wild-type tomato plants reduces aphid infestations. Aphid resistance in the spr2 mutant is associated with enhanced levels of salicylic acid (SA) and mRNA encoding the pathogenesis-related protein P4. Introduction of the Naphthalene/salicylate hydroxylase transgene, which suppresses SA accumulation, restores wild-type levels of aphid susceptibility to spr2. Resistance in spr2 is also lost when we utilize virus-induced gene silencing to suppress the expression of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1), a positive regulator of many SA-dependent defenses. These results indicate that FAD7 suppresses defenses against aphids that are mediated through SA and NPR1. Although loss of function of FAD7 also inhibits the synthesis of jasmonate (JA), the effects of this desaturase on aphid resistance are not dependent on JA; other mutants impaired in JA synthesis (acx1) or perception (jai1-1) show wild-type levels of aphid susceptibility, and spr2 retains aphid resistance when treated with methyl jasmonate. Thus, FAD7 may influence JA-dependent defenses against chewing insects and SA-dependent defenses against aphids through independent effects on JA synthesis and SA signaling. The Arabidopsis (Arabidopsis thaliana) mutants Atfad7-2 and Atfad7-1fad8 also show enhanced resistance to the green peach aphid (Myzus persicae) compared with wild-type controls, indicating that FAD7 influences plant-aphid interactions in at least two plant families. PMID:22291202

  14. Loss-of-function variants of SETD5 cause intellectual disability and the core phenotype of microdeletion 3p25.3 syndrome

    Science.gov (United States)

    Kuechler, Alma; Zink, Alexander M; Wieland, Thomas; Lüdecke, Hermann-Josef; Cremer, Kirsten; Salviati, Leonardo; Magini, Pamela; Najafi, Kimia; Zweier, Christiane; Czeschik, Johanna Christina; Aretz, Stefan; Endele, Sabine; Tamburrino, Federica; Pinato, Claudia; Clementi, Maurizio; Gundlach, Jasmin; Maylahn, Carina; Mazzanti, Laura; Wohlleber, Eva; Schwarzmayr, Thomas; Kariminejad, Roxana; Schlessinger, Avner; Wieczorek, Dagmar; Strom, Tim M; Novarino, Gaia; Engels, Hartmut

    2015-01-01

    Intellectual disability (ID) has an estimated prevalence of 2–3%. Due to its extreme heterogeneity, the genetic basis of ID remains elusive in many cases. Recently, whole exome sequencing (WES) studies revealed that a large proportion of sporadic cases are caused by de novo gene variants. To identify further genes involved in ID, we performed WES in 250 patients with unexplained ID and their unaffected parents and included exomes of 51 previously sequenced child–parents trios in the analysis. Exome analysis revealed de novo intragenic variants in SET domain-containing 5 (SETD5) in two patients. One patient carried a nonsense variant, and the other an 81 bp deletion located across a splice-donor site. Chromosomal microarray diagnostics further identified four de novo non-recurrent microdeletions encompassing SETD5. CRISPR/Cas9 mutation modelling of the two intragenic variants demonstrated nonsense-mediated decay of the resulting transcripts, pointing to a loss-of-function (LoF) and haploinsufficiency as the common disease-causing mechanism of intragenic SETD5 sequence variants and SETD5-containing microdeletions. In silico domain prediction of SETD5, a predicted SET domain-containing histone methyltransferase (HMT), substantiated the presence of a SET domain and identified a novel putative PHD domain, strengthening a functional link to well-known histone-modifying ID genes. All six patients presented with ID and certain facial dysmorphisms, suggesting that SETD5 sequence variants contribute substantially to the microdeletion 3p25.3 phenotype. The present report of two SETD5 LoF variants in 301 patients demonstrates a prevalence of 0.7% and thus SETD5 variants as a relatively frequent cause of ID. PMID:25138099

  15. TEC family kinases in health and disease--loss-of-function of BTK and ITK and the gain-of-function fusions ITK-SYK and BTK-SYK.

    Science.gov (United States)

    Hussain, Alamdar; Yu, Liang; Faryal, Rani; Mohammad, Dara K; Mohamed, Abdalla J; Smith, C I Edvard

    2011-06-01

    The TEC family is ancient and constitutes the second largest family of cytoplasmic tyrosine kinases. In 1993, loss-of-function mutations in the BTK gene were reported as the cause of X-linked agammaglobulinemia. Of all the existing 90 tyrosine kinases in humans, Bruton's tyrosine kinase (BTK) is the kinase for which most mutations have been identified. These experiments of nature collectively provide a form of mutation scanning with direct implications for the several hundred endogenous signaling proteins carrying domains also found in BTK. In 2009, an inactivating mutation in the ITK gene was shown to cause susceptibility to lethal Epstein-Barr virus infection. Both kinases represent interesting targets for inhibition: in the case of BTK, as an immunosuppressant, whereas there is evidence that the inhibition of inducible T-cell kinase (ITK) could influence the infectivity of HIV and also have anti-inflammatory activity. Since 2006, several patients carrying a fusion protein, originating from a translocation joining genes encoding the kinases ITK and spleen tyrosine kinase (SYK), have been shown to develop T-cell lymphoma. We review these disease processes and also describe the role of the N-terminal pleckstrin homology-Tec homology (PH-TH) domain doublet of BTK and ITK in the downstream intracellular signaling of such fusion proteins. © 2011 The Authors Journal compilation © 2011 FEBS.

  16. Detecting low frequent loss-of-function alleles in genome wide association studies with red hair color as example.

    Directory of Open Access Journals (Sweden)

    Fan Liu

    Full Text Available Multiple loss-of-function (LOF alleles at the same gene may influence a phenotype not only in the homozygote state when alleles are considered individually, but also in the compound heterozygote (CH state. Such LOF alleles typically have low frequencies and moderate to large effects. Detecting such variants is of interest to the genetics community, and relevant statistical methods for detecting and quantifying their effects are sorely needed. We present a collapsed double heterozygosity (CDH test to detect the presence of multiple LOF alleles at a gene. When causal SNPs are available, which may be the case in next generation genome sequencing studies, this CDH test has overwhelmingly higher power than single SNP analysis. When causal SNPs are not directly available such as in current GWA settings, we show the CDH test has higher power than standard single SNP analysis if tagging SNPs are in linkage disequilibrium with the underlying causal SNPs to at least a moderate degree (r²>0.1. The test is implemented for genome-wide analysis in the publically available software package GenABEL which is based on a sliding window approach. We provide the proof of principle by conducting a genome-wide CDH analysis of red hair color, a trait known to be influenced by multiple loss-of-function alleles, in a total of 7,732 Dutch individuals with hair color ascertained. The association signals at the MC1R gene locus from CDH were uniformly more significant than traditional GWA analyses (the most significant P for CDH = 3.11×10⁻¹⁴² vs. P for rs258322 = 1.33×10⁻⁶⁶. The CDH test will contribute towards finding rare LOF variants in GWAS and sequencing studies.

  17. Atopic diseases by filaggrin mutations and birth year

    DEFF Research Database (Denmark)

    Thyssen, J P; Linneberg, A; Johansen, J D

    2012-01-01

    The prevalence of atopic disorders has increased in recent years. The pathogenesis is complex with genetic and environmental risk factors. Filaggrin loss-of-function mutations are common and associated with atopic disorders. We investigated whether the prevalence of filaggrin mutations increased ...... in different birth cohorts in adults from the general population in Denmark....

  18. Hyperinsulinaemic hypoglycaemia and diabetes mellitus due to dominant ABCC8/KCNJ11 mutations.

    LENUS (Irish Health Repository)

    Kapoor, R R

    2011-10-01

    Dominantly acting loss-of-function mutations in the ABCC8\\/KCNJ11 genes can cause mild medically responsive hyperinsulinaemic hypoglycaemia (HH). As controversy exists over whether these mutations predispose to diabetes in adulthood we investigated the prevalence of diabetes in families with dominantly inherited ATP-sensitive potassium (K(ATP)) channel mutations causing HH in the proband.

  19. The most common mutation causing medium-chain acyl-CoA dehydrogenase deficiency is strongly associated with a particular haplotype in the region of the gene

    DEFF Research Database (Denmark)

    Kølvraa, S; Gregersen, N; Blakemore, A I

    1991-01-01

    RFLP haplotypes in the region containing the medium-chain acyl-CoA dehydrogenase (MCAD) gene on chromosome 1 have been determined in patients with MCAD deficiency. The RFLPs were detected after digestion of patient DNA with the enzymes BanII. PstI and TaqI and with an MCAD cDNA-clone as a probe....... Of 32 disease-causing alleles studied, 31 possessed the previously published A----G point-mutation at position 985 of the cDNA. This mutation has been shown to result in inactivity of the MCAD enzyme. In at least 30 of the 31 alleles carrying this G985 mutation a specific RFLP haplotype was present...

  20. Identification of a PRPF4 loss-of-function variant that abrogates U4/U6.U5 tri-snRNP integration and is associated with retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Bastian Linder

    Full Text Available Pre-mRNA splicing by the spliceosome is an essential step in the maturation of nearly all human mRNAs. Mutations in six spliceosomal proteins, PRPF3, PRPF4, PRPF6, PRPF8, PRPF31 and SNRNP200, cause retinitis pigmentosa (RP, a disease characterized by progressive photoreceptor degeneration. All splicing factors linked to RP are constituents of the U4/U6.U5 tri-snRNP subunit of the spliceosome, suggesting that the compromised function of this particle may lead to RP. Here, we report the identification of the p.R192H variant of the tri-snRNP factor PRPF4 in a patient with RP. The mutation affects a highly conserved arginine residue that is crucial for PRPF4 function. Introduction of a corresponding mutation into the zebrafish homolog of PRPF4 resulted in a complete loss of function in vivo. A series of biochemical experiments suggested that p.R192H disrupts the binding interface between PRPF4 and its interactor PRPF3. This interferes with the ability of PRPF4 to integrate into the tri-snRNP, as shown in a human cell line and in zebrafish embryos. These data suggest that the p.R192H variant of PRPF4 represents a functional null allele. The resulting haploinsufficiency of PRPF4 compromises the function of the tri-snRNP, reinforcing the notion that this spliceosomal particle is of crucial importance in the physiology of the retina.

  1. Detection of 23SrRNA Mutations Strongly Related to Clarithromycin Resistance in Helicobacter pylori Strains Isolated From Patients in the North of Iran.

    Science.gov (United States)

    Eghbali, Zahra; Mojtahedi, Ali; Moien Ansar, Malek; Fakhrieh Asl, Saba; Aminian, Keyvan

    2016-02-01

    Helicobacter pylori is curved Gram negative and microaerophilic bacilli that have infected half of the world's population. It is recognized as the causative agent of duodenal ulcer, gastritis peptic ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma and is associated with gastric adenocarcinoma. Resistance to clarithromycin is related to point mutations in 23SrRNA gene on nt 2143 and 2144, when A turns to G, and A2143G is the most important type. These mutations lead to reduced affinity of antibiotics to their ribosomal target and are considered as the main cause of treatment failure. The aim of this study was to determine the frequency of A2143G point mutation in 23SrRNA of H. pylori strains isolated from gastric biopsies of patients in Rasht, north of Iran, by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A descriptive study was performed on 89 H. pylori strains, which were isolated from gastric biopsies of patients with gastric disorders such as gastritis, peptic ulcer, duodenal ulcer, non-ulcer dyspepsia and gastric adenocarcinoma. Isolated strains were tested for clarithromycin resistance using as breakpoint a minimum inhibitory concentration (MIC) of ≥ 1 mg/L by the E-test. The presence of H. pylori DNA was confirmed by amplifying the ureC (glmM) gene by PCR. Also, point mutation on 23SrRNA gene (A2142G and A2143G) was detected by PCR-RFLP using MboII and BsaI restriction endonucleases in all extracted DNA. Of the 89 H. pylori isolates, eighty-four were susceptible to clarithromycin, while five (5.6%) were resistant. All DNA samples of resistant strains, which were treated with BsaI had A2143G mutation. There was no point mutation in the sensitive strains of H. pylori. Also, we detected no mutation on nt A2142G of resistant strains. In the present study, the frequency of clarithromycin resistance was lower than the other studies conducted in Iran. Resistance frequency in samples isolated from gastric ulcer was higher

  2. Optimization of CRISPR/Cas9 genome editing for loss-of-function in the early chick embryo.

    Science.gov (United States)

    Gandhi, Shashank; Piacentino, Michael L; Vieceli, Felipe M; Bronner, Marianne E

    2017-12-01

    The advent of CRISPR/Cas9 has made genome editing possible in virtually any organism, including those not previously amenable to genetic manipulations. Here, we present an optimization of CRISPR/Cas9 for application to early avian embryos with improved efficiency via a three-fold strategy. First, we employed Cas9 protein flanked with two nuclear localization signal sequences for improved nuclear localization. Second, we used a modified guide RNA (gRNA) scaffold that obviates premature termination of transcription and unstable Cas9-gRNA interactions. Third, we used a chick-specific U6 promoter that yields 4-fold higher gRNA expression than the previously utilized human U6. For rapid screening of gRNAs for in vivo applications, we also generated a chicken fibroblast cell line that constitutively expresses Cas9. As proof of principle, we performed electroporation-based loss-of-function studies in the early chick embryo to knock out Pax7 and Sox10, key transcription factors with known functions in neural crest development. The results show that CRISPR/Cas9-mediated deletion causes loss of their respective proteins and transcripts, as well as predicted downstream targets. Taken together, the results reveal the utility of this optimized CRISPR/Cas9 method for targeted gene knockout in chicken embryos in a manner that is reproducible, robust and specific. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Genetic background strongly modifies the severity of symptoms of Hirschsprung disease, but not hearing loss in rats carrying Ednrb(sl mutations.

    Directory of Open Access Journals (Sweden)

    Ruihua Dang

    Full Text Available Hirschsprung disease (HSCR is thought to result as a consequence of multiple gene interactions that modulate the ability of enteric neural crest cells to populate the developing gut. However, it remains unknown whether the single complete deletion of important HSCR-associated genes is sufficient to result in HSCR disease. In this study, we found that the null mutation of the Ednrb gene, thought indispensable for enteric neuron development, is insufficient to result in HSCR disease when bred onto a different genetic background in rats carrying Ednrb(sl mutations. Moreover, we found that this mutation results in serious congenital sensorineural deafness, and these strains may be used as ideal models of Waardenburg Syndrome Type 4 (WS4. Furthermore, we evaluated how the same changed genetic background modifies three features of WS4 syndrome, aganglionosis, hearing loss, and pigment disorder in these congenic strains. We found that the same genetic background markedly changed the aganglionosis, but resulted in only slight changes to hearing loss and pigment disorder. This provided the important evidence, in support of previous studies, that different lineages of neural crest-derived cells migrating along with various pathways are regulated by different signal molecules. This study will help us to better understand complicated diseases such as HSCR and WS4 syndrome.

  4. A Comprehensive Dataset of Genes with a Loss-of-Function Mutant Phenotype in Arabidopsis1[W][OA

    Science.gov (United States)

    Lloyd, Johnny; Meinke, David

    2012-01-01

    Despite the widespread use of Arabidopsis (Arabidopsis thaliana) as a model plant, a curated dataset of Arabidopsis genes with mutant phenotypes remains to be established. A preliminary list published nine years ago in Plant Physiology is outdated, and genome-wide phenotype information remains difficult to obtain. We describe here a comprehensive dataset of 2,400 genes with a loss-of-function mutant phenotype in Arabidopsis. Phenotype descriptions were gathered primarily from manual curation of the scientific literature. Genes were placed into prioritized groups (essential, morphological, cellular-biochemical, and conditional) based on the documented phenotypes of putative knockout alleles. Phenotype classes (e.g. vegetative, reproductive, and timing, for the morphological group) and subsets (e.g. flowering time, senescence, circadian rhythms, and miscellaneous, for the timing class) were also established. Gene identities were classified as confirmed (through molecular complementation or multiple alleles) or not confirmed. Relationships between mutant phenotype and protein function, genetic redundancy, protein connectivity, and subcellular protein localization were explored. A complementary dataset of 401 genes that exhibit a mutant phenotype only when disrupted in combination with a putative paralog was also compiled. The importance of these genes in confirming functional redundancy and enhancing the value of single gene datasets is discussed. With further input and curation from the Arabidopsis community, these datasets should help to address a variety of important biological questions, provide a foundation for exploring the relationship between genotype and phenotype in angiosperms, enhance the utility of Arabidopsis as a reference plant, and facilitate comparative studies with model genetic organisms. PMID:22247268

  5. The Effect of PCSK9 Loss-of-Function Variants on the Postprandial Lipid and ApoB-Lipoprotein Response.

    Science.gov (United States)

    Ooi, Teik Chye; Krysa, Jacqueline A; Chaker, Seham; Abujrad, Hussein; Mayne, Janice; Henry, Kathy; Cousins, Marion; Raymond, Angela; Favreau, Colette; Taljaard, Monica; Chrétien, Michel; Mbikay, Majambu; Proctor, Spencer D; Vine, Donna F

    2017-09-01

    Proprotein convertase subtilisin kexin 9 (PCSK9) mediates degradation of the low-density lipoprotein receptor (LDLR), thereby increasing plasma low-density lipoprotein cholesterol (LDL-C). Variations in the PCSK9 gene associated with loss of function (LOF) of PCSK9 result in greater expression of hepatic LDLR, lower concentrations of LDL-C, and protection from cardiovascular disease (CVD). Apolipoprotein-B (apoB) remnants also contribute to CVD risk and are similarly cleared by the LDLR. We hypothesized that PCSK9-LOF carriers would have lower fasting and postprandial remnant lipoproteins on top of lower LDL-C. To compare fasting and postprandial concentrations of triglycerides (TGs), total apoB, and apoB48 as indicators of remnant lipoprotein metabolism in PCSK9-LOF carriers with those with no PCSK9 variants. Case-control, metabolic study. Clinical Research Center of The Ottawa Hospital. Persons with one or more copies of the L10ins/A53V and/or I474V and/or R46L PCSK9 variant and persons with no PCSK9 variants. Oral fat tolerance test. Fasting and postprandial plasma TG, apoB48, total apoB, total cholesterol, and PCSK9 were measured at 0, 2, 4, and 6 hours after an oral fat load. Participants with PCSK9-LOF variants (n = 22) had reduced fasting LDL-C (-14%) as well as lower fasting TG (-21%) compared with noncarrier controls (n = 23). LOF variants also had reduced postprandial total apoB (-17%), apoB48 (-23%), and TG (-18%). Postprandial PCSK9 declined in both groups (-24% vs -16%, respectively). Participants carrying PCSK9-LOF variants had attenuated levels of fasting and postprandial TG, apoB48, and total apoB. This may confer protection from CVD and further validate the use of PCSK9 inhibitors to lower CVD risk. Copyright © 2017 Endocrine Society

  6. Multiple loss-of-function mechanisms contribute to SCN5A-related familial sick sinus syndrome.

    Directory of Open Access Journals (Sweden)

    Junhong Gui

    2010-06-01

    Full Text Available To identify molecular mechanisms underlying SCN5A-related sick sinus syndrome (SSS, a rare type of SSS, in parallel experiments we elucidated the electrophysiological properties and the cell surface localization of thirteen human Na(v1.5 (hNa(v1.5 mutant channels previously linked to this disease.Mutant hNa(v1.5 channels expressed by HEK293 cells and Xenopus oocytes were investigated by whole-cell patch clamp and two-microelectrode voltage clamp, respectively. HEK293 cell surface biotinylation experiments quantified the fraction of correctly targeted channel proteins. Our data suggested three distinct mutant channel subtypes: Group 1 mutants (L212P, P1298L, DelF1617, R1632H gave peak current densities and cell surface targeting indistinguishable from wild-type hNa(v1.5. Loss-of-function of these mutants resulted from altered channel kinetics, including a negative shift of steady-state inactivation and a reduced voltage dependency of open-state inactivation. Group 2 mutants (E161K, T220I, D1275N gave significantly reduced whole-cell currents due to impaired cell surface localization (D1275N, altered channel properties at unchanged cell surface localization (T220I, or a combination of both (E161K. Group 3 mutant channels were non-functional, due to an almost complete lack of protein at the plasma membrane (T187I, W1421X, K1578fs/52, R1623X or a probable gating/permeation defect with normal surface localisation (R878C, G1408R.This study indicates that multiple molecular mechanisms, including gating abnormalities, trafficking defects, or a combination of both, are responsible for SCN5A-related familial SSS.

  7. Exome Sequencing and Functional Validation in Zebrafish Identify GTDC2 Mutations as a Cause of Walker-Warburg Syndrome

    Science.gov (United States)

    Manzini, M. Chiara; Tambunan, Dimira E.; Hill, R. Sean; Yu, Tim W.; Maynard, Thomas M.; Heinzen, Erin L.; Shianna, Kevin V.; Stevens, Christine R.; Partlow, Jennifer N.; Barry, Brenda J.; Rodriguez, Jacqueline; Gupta, Vandana A.; Al-Qudah, Abdel-Karim; Eyaid, Wafaa M.; Friedman, Jan M.; Salih, Mustafa A.; Clark, Robin; Moroni, Isabella; Mora, Marina; Beggs, Alan H.; Gabriel, Stacey B.; Walsh, Christopher A.

    2012-01-01

    Whole-exome sequencing (WES), which analyzes the coding sequence of most annotated genes in the human genome, is an ideal approach to studying fully penetrant autosomal-recessive diseases, and it has been very powerful in identifying disease-causing mutations even when enrollment of affected individuals is limited by reduced survival. In this study, we combined WES with homozygosity analysis of consanguineous pedigrees, which are informative even when a single affected individual is available, to identify genetic mutations responsible for Walker-Warburg syndrome (WWS), a genetically heterogeneous autosomal-recessive disorder that severely affects the development of the brain, eyes, and muscle. Mutations in seven genes are known to cause WWS and explain 50%–60% of cases, but multiple additional genes are expected to be mutated because unexplained cases show suggestive linkage to diverse loci. Using WES in consanguineous WWS-affected families, we found multiple deleterious mutations in GTDC2 (also known as AGO61). GTDC2’s predicted role as an uncharacterized glycosyltransferase is consistent with the function of other genes that are known to be mutated in WWS and that are involved in the glycosylation of the transmembrane receptor dystroglycan. Therefore, to explore the role of GTDC2 loss of function during development, we used morpholino-mediated knockdown of its zebrafish ortholog, gtdc2. We found that gtdc2 knockdown in zebrafish replicates all WWS features (hydrocephalus, ocular defects, and muscular dystrophy), strongly suggesting that GTDC2 mutations cause WWS. PMID:22958903

  8. Loss-of-function mutants and overexpression lines of the Arabidopsis cyclin CYCA1;2/Tardy Asynchronous Meiosis exhibit different defects in prophase-i meiocytes but produce the same meiotic products.

    Directory of Open Access Journals (Sweden)

    Yixing Wang

    Full Text Available In Arabidopsis, loss-of-function mutations in the A-type cyclin CYCA1;2/Tardy Asynchronous Meiosis (TAM gene lead to the production of abnormal meiotic products including triads and dyads. Here we report that overexpression of TAM by the ASK1:TAM transgene also led to the production of triads and dyads in meiosis, as well as shriveled seeds, in a dominant fashion. However, the partial loss-of-function mutant tam-1, an ASK1:TAM line, and the wild type differed in dynamic changes in chromosome thread thickness from zygotene to diplotene. We also found that the pericentromeric heterochromatin regions in male meiocytes in tam-1 and tam-2 (a null allele frequently formed a tight cluster at the pachytene and diplotene stages, in contrast to the infrequent occurrences of such clusters in the wild type and the ASK1:TAM line. Immunolocalization studies of the chromosome axial component ASY1 revealed that ASY1 was highly expressed at the appropriate male meiotic stages but not localized to the chromosomes in tam-2. The level of ASY1, however, was greatly reduced in another ASK1:TAM line with much overexpressed TAM. Our results indicate that the reduction and increase in the activity of TAM differentially affect chromosomal morphology and the action of ASY1 in prophase I. Based on these results, we propose that either the different meiotic defects or a common defect such as missing ASY1 on the chromosomal axes triggers a hitherto uncharacterized cell cycle checkpoint in the male meiocytes in the tam mutants and ASK1:TAM lines, leading to the production of the same abnormal meiotic products.

  9. Gene-environment interaction in the onset of eczema in infancy: filaggrin loss-of-function mutations enhanced by neonatal cat exposure.

    OpenAIRE

    Bisgaard, H; Simpson, A; Palmer, CN; B?nnelykke, K; McLean, I; Mukhopadhyay, S; Pipper, CB; Halkjaer, LB; Lipworth, B; Hankinson, J; Woodcock, A; Custovic, A

    2008-01-01

    Editors' Summary Background. Eczema is a skin condition characterized by dry, red, and itchy patches on the skin. Eczema is associated with asthma and allergy, though allergy rarely plays a role in development or severity of eczema. Eczema usually begins during infancy, typically on the face, scalp, neck, extensor sides of the forearms, and legs. Up to one in five infants develops eczema, but in more than half of them, the condition improves or disappears completely before they are 15 years o...

  10. Loss-of-Function Mutations in LGI4, a Secreted Ligand Involved in Schwann Cell Myelination, Are Responsible for Arthrogryposis Multiplex Congenita

    NARCIS (Netherlands)

    Xue, Shifeng; Maluenda, Jérôme; Marguet, Florent; Shboul, Mohammad; Quevarec, Loïc; Bonnard, Carine; Ng, Alvin Yu Jin; Tohari, Sumanty; Tan, Thong Teck; Kong, Mung Kei; Monaghan, Kristin G.; Cho, Megan T.; Siskind, Carly E.; Sampson, Jacinda B.; Rocha, Carolina Tesi; Alkazaleh, Fawaz; Gonzales, Marie; Rigonnot, Luc; Whalen, Sandra; Gut, Marta; Gut, Ivo; Bucourt, Martine; Venkatesh, Byrappa; Laquerrière, Annie; Reversade, Bruno; Melki, Judith

    2017-01-01

    Arthrogryposis multiplex congenita (AMC) is a developmental condition characterized by multiple joint contractures resulting from reduced or absent fetal movements. Through genetic mapping of disease loci and whole-exome sequencing in four unrelated multiplex families presenting with severe AMC, we

  11. PCSK9 R46L Loss-of-Function Mutation Reduces Lipoprotein(a), LDL Cholesterol, and Risk of Aortic Valve Stenosis

    DEFF Research Database (Denmark)

    Langsted, Anne; Nordestgaard, Børge; Benn, Marianne

    2016-01-01

    CONTEXT: Novel, low-density lipoprotein (LDL) cholesterol-lowering proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors also lower lipoprotein(a) levels, but the effect on aortic valve stenosis and myocardial infarction is unknown. OBJECTIVE: We tested the hypothesis that the PCSK9 R46L...... individuals of Danish descent. PARTICIPANTS: We studied 103 083 individuals from the Copenhagen General Population Study, the Copenhagen City Heart Study, and the Copenhagen Ischemic Heart Disease Study. MAIN OUTCOME MEASURES: Lipoprotein(a), LDL cholesterol, and PCSK9 R46L genotype and diagnoses of aortic...... P = .02). The corresponding values for LDL cholesterol levels were 124 (101-147) mg/dl, 104 (85-132) mg/dl, and 97 (85-128) mg/dl, respectively (trend P = 2 × 10(-52)). PCSK9 R46L carriers vs noncarriers had an age- and sex-adjusted odds ratio of 0.64 (95% confidence interval, 0.44-0.95) for aortic...

  12. Association of loss-of-function mutations in the ABCA1 gene with high-density lipoprotein cholesterol levels and risk of ischemic heart disease

    DEFF Research Database (Denmark)

    Frikke-Schmidt, R.; Nordestgaard, B.G.; Stene, M.C.A.

    2008-01-01

    increased risk of ischemic heart disease ( IHD). Design, Setting, and Participants Three studies of white individuals from Copenhagen, Denmark, were used: the Copenhagen City Heart Study ( CCHS), a 31-year prospective general population study ( n= 9022; 28 heterozygotes); the Copenhagen General Population...

  13. Heterozygous Loss-of-Function SEC61A1 Mutations Cause Autosomal-Dominant Tubulo-Interstitial and Glomerulocystic Kidney Disease with Anemia

    Czech Academy of Sciences Publication Activity Database

    Bolar, N. A.; Golzio, C.; Živná, M.; Hayot, G.; Van Hemelrijk, C.; Schepers, D.; Vandeweyer, G.; Hoischen, A.; Huyghe, J. R.; Raes, A.; Matthys, E.; Sys, E.; Azou, M.; Gubler, M. C.; Praet, M.; Van Camp, G.; McFadden, K.; Pediaditakis, I.; Přistoupilová, A.; Hodaňová, K.; Vyleťal, P.; Hartmannová, H.; Stránecký, V.; Hůlková, H.; Barešová, V.; Jedličková, I.; Sovová, J.; Hnízda, Aleš; Kidd, K.; Bleyer, A. J.; Spong, R. S.; Vande Walle, J.; Mortier, G.; Brunner, H.; Van Laer, L.; Kmoch, S.; Katsanis, N.; Loeys, B. L.

    2016-01-01

    Roč. 99, č. 1 (2016), s. 174-187 ISSN 0002-9297 R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : Sec61 * tubulo-interstitial kidney disease * rare disease Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.025, year: 2016 http://www.sciencedirect.com/science/article/pii/S0002929716301999

  14. Investigation about selecting strong type of melons by using melon paleness factor fusarium oxysporum f.sp.melonis and mutation techniques

    International Nuclear Information System (INIS)

    Kantoglu, Y.; Secer, E.; Kunter, B.; Erzurum, K.; Maden, S.; Yanmaz, R.

    2009-01-01

    Fusarium wilt is a vascular disease of the Cucurbitaceae family, especially in muskmelon (Cucumis melo L.), caused by the soil fungus Fusarium oxysporum f. sp. melonis (FOM). This pathogen persists in the soil for extended periods of time, and the only effective control is the use of resistant varieties. Fusarium oxysporum f. sp. melonis is a very serious disease factor for farmers in Turkey. In this research, we show a method for mass-selection of melon mutants resistant to Fusarium wilt. In vitro selection of resistant cells, which are come from irradiated and non-irradiated explants, is done using culture filtrates of different FOM races. According to our results we determined effective irradiation doses and filtrate treatment dose by Linear Regression Analysis. According to our results 21.75 Gy is effective dose for in vitro Yuva cv. explants to induce mutation and for filtrate treatment 6.73% is the proper dose to select survive calluses and plantlets. We recommended using 10 and 20 Gy gamma ray doses for in vitro melon plantlets to induce mutation by our results. We succeed to regenerate 6% plantlets which were obtained and selected from irradiated plantlets and regenerated in in vitro medias which were include 6.73 % filtrate. Although 16.7% of resistant or tolerant plantlets can continue their viability in greenhouse conditions after disease inoculation treatment, we observed 4 plants had a surviving capability in a limited time. That is very important for breeding cycle and this research can lead to the development of new melon cultivars that will be resistant to Fusarium wilt.

  15. Mutation Update for UBE3A variants in Angelman syndrome.

    Science.gov (United States)

    Sadikovic, Bekim; Fernandes, Priscilla; Zhang, Victor Wei; Ward, Patricia A; Miloslavskaya, Irene; Rhead, William; Rosenbaum, Richard; Gin, Robert; Roa, Benjamin; Fang, Ping

    2014-12-01

    Angelman syndrome is a neurodevelopmental disorder caused by a deficiency of the imprinted and maternally expressed UBE3A gene. Although de novo genetic and epigenetic imprinting defects of UBE3A genomic locus account for majority of Angelman diagnoses, approximately 10% of individuals affected with Angelman syndrome are a result of UBE3A loss-of-function mutations occurring on the expressed maternal chromosome. The variants described in this manuscript represent the analysis of 2,515 patients referred for UBE3A gene sequencing at our institution, along with a comprehensive review of the UBE3A mutation literature. Of these, 267 (10.62%) patients had a report issued for detection of a UBE3A gene nucleotide variant, which in many cases involved family studies resulting in reclassification of variants of unknown clinical significance (VUS). Overall, 111 (4.41%) probands had a nucleotide change classified as pathogenic or strongly favored to be pathogenic, 29 (1.15%) had a VUS, and 126 (5.0%) had a nucleotide change classified as benign or strongly favored to be benign. All variants and their clinical interpretations are submitted to NCBI ClinVar, a freely accessible human variation and phenotype database. © 2014 WILEY PERIODICALS, INC.

  16. DBI/ACBP loss-of-function does not affect anxiety-like behaviour but reduces anxiolytic responses to diazepam in mice

    DEFF Research Database (Denmark)

    Budry, Lionel; Bouyakdan, Khalil; Tobin, Stephanie

    2016-01-01

    . Male and female ACBP(GFAP) KO and ACBP KO mice do not show significant changes in anxiety-like behaviour compared to control littermates during elevated plus maze (EPM) and open field (OF) tests. Surprisingly, ACBP(GFAP) KO and ACBP KO mice were unresponsive to the anxiolytic effect of a low dose......-like behaviour and anxiolytic responses to diazepam has not been investigated. To address this question, we assessed anxiety behaviour and anxiolytic responses to diazepam in two complementary loss-of-function mouse models including astrocyte-specific ACBP KO (ACBP(GFAP) KO) and whole-body KO (ACBP KO) mice...... of diazepam during EPM tests. In conclusion, our experiments using genetic ACBP loss-of-function models suggest that endozepines deficiency does not affect anxiety-like behaviour in mice and impairs the anxiolytic action of diazepam....

  17. Genotype-phenotype relationship in patients with mutations in thyroid hormone transporter MCT8

    NARCIS (Netherlands)

    J.A. Jansen (John); E.C.H. Friesema (Edith); M.H.A. Kester (Monique); C.E. Schwartz; T.J. Visser (Theo)

    2008-01-01

    textabstractLoss-of-function mutations in thyroid hormone transporter monocarboxylate transporter 8 (MCT8) lead to severe X-linked psychomotor retardation and elevated serum T3levels. Most patients, for example those with mutations V235M, S448X, insI189, or delF230, cannot stand, walk, or speak.

  18. It Remains Unknown Whether Filaggrin Gene Mutations Evolved to Increase Cutaneous Synthesis of Vitamin D

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Elias, Peter M

    2017-01-01

    advantage for heterozygous FLG mutation carriers, residing at northern latitudes, depletion of the FLG downstream product, trans-urocanic acid, would facilitate the intracutaneous synthesis of vitamin D3 by allowing increased transcutaneous absorption of UVB photons. Such loss-of-function FLG mutations...

  19. Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

    NARCIS (Netherlands)

    Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Dörfler, Arnd; Kinning, Esther; Megarbane, André; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Dörr, Helmuth-Günther; Reis, André

    2008-01-01

    Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism

  20. Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

    NARCIS (Netherlands)

    Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Doerfler, Arnd; Kinning, Esther; Megarbane, Andre; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Doerr, Helmuth-Guenther; Reis, Andre

    2008-01-01

    Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss- of- function mutations in the centrosomal pericentrin ( PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial

  1. Mutations affecting glycinergic neurotransmission in hyperekplexia increase pain sensitivity

    DEFF Research Database (Denmark)

    Vuilleumier, Pascal Henri; Fritsche, Raphael; Schliessbach, Jürg

    2018-01-01

    these pathways in humans. Hyperekplexia is a rare human disease that is caused by loss-of-function mutations in genes encoding for glycine receptors and glycine transporters. In the present study, we tested whether hyperekplexia patients display altered pain perception or central pain modulation compared...

  2. The cardiac phenotype in patients with a CHD7 mutation

    DEFF Research Database (Denmark)

    Corsten-Janssen, Nicole; Kerstjens-Frederikse, Wilhelmina S; du Marchie Sarvaas, Gideon J

    2013-01-01

    Loss-of-function mutations in CHD7 cause Coloboma, Heart Disease, Atresia of Choanae, Retardation of Growth and/or Development, Genital Hypoplasia, and Ear Abnormalities With or Without Deafness (CHARGE) syndrome, a variable combination of multiple congenital malformations including heart defects...

  3. Loss of functional E-cadherin renders cells more resistant to the apoptotic agent taxol in vitro

    International Nuclear Information System (INIS)

    Ferreira, Paulo; Oliveira, Maria Jose; Beraldi, Eliana; Mateus, Ana Rita; Nakajima, Takashi; Gleave, Martin; Yokota, Jun; Carneiro, Fatima; Huntsman, David; Seruca, Raquel; Suriano, Gianpaolo

    2005-01-01

    Experimental evidence supports a role for E-cadherin in suppressing invasion, metastasis, and proliferation. Germline mutations of the E-cadherin represent the genetic cause of hereditary diffuse gastric cancer (HDGC). In this type of tumor, isolated cancer cells permeate the basal membrane and paradoxically survive in the gastric wall in the absence of contact with neighbor epithelial cells or with the extracellular matrix. This suggests that upon E-cadherin deregulation, cells acquired resistance to apoptosis. To test this hypothesis, CHO cells stably expressing either wild-type E-cadherin or the HDGC-related germline mutations T340A and V832M were seeded either on a thin layer of collagen type I or on plastic and then subjected to the apoptotic agent taxol. We found that in vitro functional E-cadherin renders cells more sensitive to the effect of taxol. Our results also indicate that this effect is associated to decreased level of the anti-apoptotic bcl-2 protein

  4. Mutations in POGLUT1, encoding protein O-glucosyltransferase 1, cause autosomal-dominant Dowling-Degos disease.

    Science.gov (United States)

    Basmanav, F Buket; Oprisoreanu, Ana-Maria; Pasternack, Sandra M; Thiele, Holger; Fritz, Günter; Wenzel, Jörg; Größer, Leopold; Wehner, Maria; Wolf, Sabrina; Fagerberg, Christina; Bygum, Anette; Altmüller, Janine; Rütten, Arno; Parmentier, Laurent; El Shabrawi-Caelen, Laila; Hafner, Christian; Nürnberg, Peter; Kruse, Roland; Schoch, Susanne; Hanneken, Sandra; Betz, Regina C

    2014-01-02

    Dowling-Degos disease (DDD) is an autosomal-dominant genodermatosis characterized by progressive and disfiguring reticulate hyperpigmentation. We previously identified loss-of-function mutations in KRT5 but were only able to detect pathogenic mutations in fewer than half of our subjects. To identify additional causes of DDD, we performed exome sequencing in five unrelated affected individuals without mutations in KRT5. Data analysis identified three heterozygous mutations from these individuals, all within the same gene. These mutations, namely c.11G>A (p.Trp4*), c.652C>T (p.Arg218*), and c.798-2A>C, are within POGLUT1, which encodes protein O-glucosyltransferase 1. Further screening of unexplained cases for POGLUT1 identified six additional mutations, as well as two of the above described mutations. Immunohistochemistry of skin biopsies of affected individuals with POGLUT1 mutations showed significantly weaker POGLUT1 staining in comparison to healthy controls with strong localization of POGLUT1 in the upper parts of the epidermis. Immunoblot analysis revealed that translation of either wild-type (WT) POGLUT1 or of the protein carrying the p.Arg279Trp substitution led to the expected size of about 50 kDa, whereas the c.652C>T (p.Arg218*) mutation led to translation of a truncated protein of about 30 kDa. Immunofluorescence analysis identified a colocalization of the WT protein with the endoplasmic reticulum and a notable aggregating pattern for the truncated protein. Recently, mutations in POFUT1, which encodes protein O-fucosyltransferase 1, were also reported to be responsible for DDD. Interestingly, both POGLUT1 and POFUT1 are essential regulators of Notch activity. Our results furthermore emphasize the important role of the Notch pathway in pigmentation and keratinocyte morphology. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  5. Maternal filaggrin mutations increase the risk of atopic dermatitis in children: an effect independent of mutation inheritance.

    Directory of Open Access Journals (Sweden)

    Jorge Esparza-Gordillo

    2015-03-01

    Full Text Available Epidemiological studies suggest that allergy risk is preferentially transmitted through mothers. This can be due to genomic imprinting, where the phenotype effect of an allele depends on its parental origin, or due to maternal effects reflecting the maternal genome's influence on the child during prenatal development. Loss-of-function mutations in the filaggrin gene (FLG cause skin barrier deficiency and strongly predispose to atopic dermatitis (AD. We investigated the 4 most prevalent European FLG mutations (c.2282del4, p.R501X, p.R2447X, and p.S3247X in two samples including 759 and 450 AD families. We used the multinomial and maximum-likelihood approach implemented in the PREMIM/EMIM tool to model parent-of-origin effects. Beyond the known role of FLG inheritance in AD (R1meta-analysis = 2.4, P = 1.0 x 10-36, we observed a strong maternal FLG genotype effect that was consistent in both independent family sets and for all 4 mutations analysed. Overall, children of FLG-carrier mothers had a 1.5-fold increased AD risk (S1 = 1.50, Pmeta-analysis = 8.4 x 10-8. Our data point to two independent and additive effects of FLG mutations: i carrying a mutation and ii having a mutation carrier mother. The maternal genotype effect was independent of mutation inheritance and can be seen as a non-genetic transmission of a genetic effect. The FLG maternal effect was observed only when mothers had allergic sensitization (elevated allergen-specific IgE antibody plasma levels, suggesting that FLG mutation-induced systemic immune responses in the mother may influence AD risk in the child. Notably, the maternal effect reported here was stronger than most common genetic risk factors for AD recently identified through genome-wide association studies (GWAS. Our study highlights the power of family-based studies in the identification of new etiological mechanisms and reveals, for the first time, a direct influence of the maternal genotype on the offspring

  6. Albinism in phylogenetically and geographically distinct populations of Astyanax cavefish arises through the same loss-of-function Oca2 allele

    Science.gov (United States)

    Gross, J B; Wilkens, H

    2013-01-01

    The Mexican tetra, Astyanax mexicanus, comprises 29 populations of cave-adapted fish distributed across a vast karst region in northeastern Mexico. These populations have a complex evolutionary history, having descended from ‘old' and ‘young' ancestral surface-dwelling stocks that invaded the region ∼6.7 and ∼2.8 MYa, respectively. This study investigates a set of captive, pigmented Astyanax cavefish collected from the Micos cave locality in 1970, in which albinism appeared over the past two decades. We combined novel coloration analyses, coding sequence comparisons and mRNA expression level studies to investigate the origin of albinism in captive-bred Micos cavefish. We discovered that albino Micos cavefish harbor two copies of a loss-of-function ocular and cutaneous albinism type II (Oca2) allele previously identified in the geographically distant Pachón cave population. This result suggests that phylogenetically young Micos cavefish and phylogenetically old Pachón cave fish inherited this Oca2 allele from the ancestral surface-dwelling taxon. This likely resulted from the presence of the loss-of-function Oca2 haplotype in the ‘young' ancestral surface-dwelling stock that colonized the Micos cave and also introgressed into the ancient Pachón cave population. The appearance of albinism in captive Micos cavefish, caused by the same loss-of-function allele present in Pachón cavefish, implies that geographically and phylogenetically distinct cave populations can evolve the same troglomorphic phenotype from standing genetic variation present in the ancestral taxon. PMID:23572122

  7. Albinism in phylogenetically and geographically distinct populations of Astyanax cavefish arises through the same loss-of-function Oca2 allele.

    Science.gov (United States)

    Gross, J B; Wilkens, H

    2013-08-01

    The Mexican tetra, Astyanax mexicanus, comprises 29 populations of cave-adapted fish distributed across a vast karst region in northeastern Mexico. These populations have a complex evolutionary history, having descended from 'old' and 'young' ancestral surface-dwelling stocks that invaded the region ∼6.7 and ∼2.8 MYa, respectively. This study investigates a set of captive, pigmented Astyanax cavefish collected from the Micos cave locality in 1970, in which albinism appeared over the past two decades. We combined novel coloration analyses, coding sequence comparisons and mRNA expression level studies to investigate the origin of albinism in captive-bred Micos cavefish. We discovered that albino Micos cavefish harbor two copies of a loss-of-function ocular and cutaneous albinism type II (Oca2) allele previously identified in the geographically distant Pachón cave population. This result suggests that phylogenetically young Micos cavefish and phylogenetically old Pachón cave fish inherited this Oca2 allele from the ancestral surface-dwelling taxon. This likely resulted from the presence of the loss-of-function Oca2 haplotype in the 'young' ancestral surface-dwelling stock that colonized the Micos cave and also introgressed into the ancient Pachón cave population. The appearance of albinism in captive Micos cavefish, caused by the same loss-of-function allele present in Pachón cavefish, implies that geographically and phylogenetically distinct cave populations can evolve the same troglomorphic phenotype from standing genetic variation present in the ancestral taxon.

  8. Functional and Morphological Correlates in the Drosophila LRRK2 loss-of-function Model of Parkinson's Disease: Drug Effects of Withania somnifera (Dunal Administration.

    Directory of Open Access Journals (Sweden)

    Francescaelena De Rose

    Full Text Available The common fruit fly Drosophila melanogaster (Dm is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2 loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD. Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+ or as adults (L-/A+ only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared to WT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a locomotor activity b muscle electrophysiological response to stimuli and also c protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is required.

  9. Functional and Morphological Correlates in the Drosophila LRRK2 loss-of-function Model of Parkinson’s Disease: Drug Effects of Withania somnifera (Dunal) Administration

    Science.gov (United States)

    Catelani, Tiziano; Setzu, Maria Dolores; Solla, Paolo; Marrosu, Francesco; Sanna, Enrico; Kasture, Sanjay; Acquas, Elio

    2016-01-01

    The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson’s disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared to WT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is required. PMID:26727265

  10. MEK inhibitors block growth of lung tumours with mutations in ataxia–telangiectasia mutated

    Science.gov (United States)

    Smida, Michal; Fece de la Cruz, Ferran; Kerzendorfer, Claudia; Uras, Iris Z.; Mair, Barbara; Mazouzi, Abdelghani; Suchankova, Tereza; Konopka, Tomasz; Katz, Amanda M.; Paz, Keren; Nagy-Bojarszky, Katalin; Muellner, Markus K.; Bago-Horvath, Zsuzsanna; Haura, Eric B.; Loizou, Joanna I.; Nijman, Sebastian M. B.

    2016-01-01

    Lung cancer is the leading cause of cancer deaths, and effective treatments are urgently needed. Loss-of-function mutations in the DNA damage response kinase ATM are common in lung adenocarcinoma but directly targeting these with drugs remains challenging. Here we report that ATM loss-of-function is synthetic lethal with drugs inhibiting the central growth factor kinases MEK1/2, including the FDA-approved drug trametinib. Lung cancer cells resistant to MEK inhibition become highly sensitive upon loss of ATM both in vitro and in vivo. Mechanistically, ATM mediates crosstalk between the prosurvival MEK/ERK and AKT/mTOR pathways. ATM loss also enhances the sensitivity of KRAS- or BRAF-mutant lung cancer cells to MEK inhibition. Thus, ATM mutational status in lung cancer is a mechanistic biomarker for MEK inhibitor response, which may improve patient stratification and extend the applicability of these drugs beyond RAS and BRAF mutant tumours. PMID:27922010

  11. Mutations in POGLUT1, Encoding Protein O-Glucosyltransferase 1, Cause Autosomal-Dominant Dowling-Degos Disease

    OpenAIRE

    Basmanav, F. Buket; Oprisoreanu, Ana-Maria; Pasternack, Sandra M.; Thiele, Holger; Fritz, Günter; Wenzel, Jörg; Größer, Leopold; Wehner, Maria; Wolf, Sabrina; Fagerberg, Christina; Bygum, Anette; Altmüller, Janine; Rütten, Arno; Parmentier, Laurent; El Shabrawi-Caelen, Laila

    2014-01-01

    Dowling-Degos disease (DDD) is an autosomal-dominant genodermatosis characterized by progressive and disfiguring reticulate hyperpigmentation. We previously identified loss-of-function mutations in KRT5 but were only able to detect pathogenic mutations in fewer than half of our subjects. To identify additional causes of DDD, we performed exome sequencing in five unrelated affected individuals without mutations in KRT5. Data analysis identified three heterozygous mutations from these individua...

  12. Expanding the mutation spectrum in ICF syndrome: Evidence for a gender bias in ICF2.

    Science.gov (United States)

    van den Boogaard, M L; Thijssen, P E; Aytekin, C; Licciardi, F; Kıykım, A A; Spossito, L; Dalm, V A S H; Driessen, G J; Kersseboom, R; de Vries, F; van Ostaijen-Ten Dam, M M; Ikinciogullari, A; Dogu, F; Oleastro, M; Bailardo, E; Daxinger, L; Nain, E; Baris, S; van Tol, M J D; Weemaes, C; van der Maarel, S M

    2017-10-01

    Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a rare, genetically heterogeneous, autosomal recessive disorder. Patients suffer from recurrent infections caused by reduced levels or absence of serum immunoglobulins. Genetically, 4 subtypes of ICF syndrome have been identified to date: ICF1 (DNMT3B mutations), ICF2 (ZBTB24 mutations), ICF3 (CDCA7 mutations), and ICF4 (HELLS mutations). To study the mutation spectrum in ICF syndrome. Genetic studies were performed in peripheral blood lymphocyte DNA from suspected ICF patients and family members. We describe 7 ICF1 patients and 6 novel missense mutations in DNMT3B, affecting highly conserved residues in the catalytic domain. We also describe 5 new ICF2 patients, one of them carrying a homozygous deletion of the complete ZBTB24 locus. In a meta-analysis of all published ICF cases, we observed a gender bias in ICF2 with 79% male patients. The biallelic deletion of ZBTB24 provides strong support for the hypothesis that most ICF2 patients suffer from a ZBTB24 loss of function mechanism and confirms that complete absence of ZBTB24 is compatible with human life. This is in contrast to the observed early embryonic lethality in mice lacking functional Zbtb24. The observed gender bias seems to be restricted to ICF2 as it is not observed in the ICF1 cohort. Our study expands the mutation spectrum in ICF syndrome and supports that DNMT3B and ZBTB24 are the most common disease genes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. BRCA mutations cause reduction in miR-200c expression in triple negative breast cancer.

    Science.gov (United States)

    Erturk, Elif; Cecener, Gulsah; Tezcan, Gulcin; Egeli, Unal; Tunca, Berrin; Gokgoz, Sehsuvar; Tolunay, Sahsine; Tasdelen, Ismet

    2015-02-10

    Triple negative breast cancer (TNBC) is the most aggressive and poorly understood subclass of breast cancer (BC). Over the recent years, miRNA expression studies have been providing certain detailed overview that aberrant expression of miRNAs is associated with TNBC. Although TNBC tumors are strongly connected with loss of function of BRCA genes, there is no knowledge about the effect of BRCA mutation status on miRNA expressions in TNBC cases. The aims of this study were to evaluate the expression profile of miRNAs that plays role in TNBC progression and the role of BRCA mutations in their regulation. The expression level of BC associated 13 miRNAs was analyzed in 7 BRCA mutations positive, 6 BRCA mutations negative TNBC cases and 20 non-tumoral tissues using RT-PCR. According to RT2 Profiler PCR Array Data Analysis, let-7a expression was 4.67 fold reduced in TNBCs as compared to normal tissues (P=0.031). In addition, miR-200c expression was 5.75 fold reduced in BRCA mutation positive TNBC tumors (P=0.005). Analysis revealed a negative correlation between miR-200c and VEGFA expressions (r=-468). Thus, miR-200c may be involved in invasion and metastasis in TNBC cases with BRCA mutation. In this study we provide the knowledge on the first report of association between microRNA-200c and BRCA mutations in TNBC. Further studies and evaluations are required, but this miRNA may provide novel therapeutic molecular targets for TNBC treatment and new directions for the development of anticancer drugs. Copyright © 2014. Published by Elsevier B.V.

  14. Mutations in POGLUT1, Encoding Protein O-Glucosyltransferase 1, Cause Autosomal-Dominant Dowling-Degos Disease

    DEFF Research Database (Denmark)

    Basmanav, F Buket; Oprisoreanu, Ana-Maria; Pasternack, Sandra M

    2014-01-01

    Dowling-Degos disease (DDD) is an autosomal-dominant genodermatosis characterized by progressive and disfiguring reticulate hyperpigmentation. We previously identified loss-of-function mutations in KRT5 but were only able to detect pathogenic mutations in fewer than half of our subjects. To ident...

  15. Early onset obesity and adrenal insufficiency associated with a homozygous POMC mutation

    OpenAIRE

    Mendiratta, Meenal S; Yang, Yaping; Balazs, Andrea E; Willis, Alecia S; Eng, Christine M; Karaviti, Lefkothea P; Potocki, Lorraine

    2011-01-01

    Abstract Isolated hypocortisolism due to ACTH deficiency is a rare condition that can be caused by homozygous or compound heterozygous mutations in the gene encoding proopiomelanocortin (POMC). Loss of function mutations of POMC gene typically results in adrenal insufficiency, obesity and red hair. We describe an 18 month old Hispanic female with congenital adrenal insufficiency, a novel POMC mutation and atypical clinical features. The patient presented at the age of 9 months with hypoglycem...

  16. DBI/ACBP loss-of-function does not affect anxiety-like behaviour but reduces anxiolytic responses to diazepam in mice.

    Science.gov (United States)

    Budry, Lionel; Bouyakdan, Khalil; Tobin, Stephanie; Rodaros, Demetra; Marcher, Ann-Britt; Mandrup, Susanne; Fulton, Stephanie; Alquier, Thierry

    2016-10-15

    Diazepam is well known for its anxiolytic properties, which are mediated via activation of the GABAA receptor. Diazepam Binding Inhibitor (DBI), also called acyl-CoA binding protein (ACBP), is a ubiquitously expressed protein originally identified based on its ability to displace diazepam from its binding site on the GABAA receptor. Central administration of ACBP or its cleaved fragment, commonly referred to as endozepines, induces proconflict and anxiety-like behaviour in rodents. For this reason, ACBP is known as an anxiogenic peptide. However, the role of endogenous ACBP in anxiety-like behaviour and anxiolytic responses to diazepam has not been investigated. To address this question, we assessed anxiety behaviour and anxiolytic responses to diazepam in two complementary loss-of-function mouse models including astrocyte-specific ACBP KO (ACBP(GFAP) KO) and whole-body KO (ACBP KO) mice. Male and female ACBP(GFAP) KO and ACBP KO mice do not show significant changes in anxiety-like behaviour compared to control littermates during elevated plus maze (EPM) and open field (OF) tests. Surprisingly, ACBP(GFAP) KO and ACBP KO mice were unresponsive to the anxiolytic effect of a low dose of diazepam during EPM tests. In conclusion, our experiments using genetic ACBP loss-of-function models suggest that endozepines deficiency does not affect anxiety-like behaviour in mice and impairs the anxiolytic action of diazepam. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. HDL from apoA1 transgenic mice expressing the 4WF isoform is resistant to oxidative loss of function[S

    Science.gov (United States)

    Berisha, Stela Z.; Brubaker, Greg; Kasumov, Takhar; Hung, Kimberly T.; DiBello, Patricia M.; Huang, Ying; Li, Ling; Willard, Belinda; Pollard, Katherine A.; Nagy, Laura E.; Hazen, Stanley L.; Smith, Jonathan D.

    2015-01-01

    HDL functions are impaired by myeloperoxidase (MPO), which selectively targets and oxidizes human apoA1. We previously found that the 4WF isoform of human apoA1, in which the four tryptophan residues are substituted with phenylalanine, is resistant to MPO-mediated loss of function. The purpose of this study was to generate 4WF apoA1 transgenic mice and compare functional properties of the 4WF and wild-type human apoA1 isoforms in vivo. Male mice had significantly higher plasma apoA1 levels than females for both isoforms of human apoA1, attributed to different production rates. With matched plasma apoA1 levels, 4WF transgenics had a trend for slightly less HDL-cholesterol versus human apoA1 transgenics. While 4WF transgenics had 31% less reverse cholesterol transport (RCT) to the plasma compartment, equivalent RCT to the liver and feces was observed. Plasma from both strains had similar ability to accept cholesterol and facilitate ex vivo cholesterol efflux from macrophages. Furthermore, we observed that 4WF transgenic HDL was partially (∼50%) protected from MPO-mediated loss of function while human apoA1 transgenic HDL lost all ABCA1-dependent cholesterol acceptor activity. In conclusion, the structure and function of HDL from 4WF transgenic mice was not different than HDL derived from human apoA1 transgenic mice. PMID:25561462

  18. Methylation of the S f locus in almond is associated with S-RNase loss of function.

    Science.gov (United States)

    Fernández i Martí, Angel; Gradziel, Thomas M; Socias i Company, Rafel

    2014-12-01

    Self-compatibility in almond (Prunus dulcis) is attributed to the presence of the S f haplotype, allelic to and dominant over the series of S-alleles controlling self-incompatibility. Some forms of the S f haplotype, however, are phenotypically self-incompatible even though their nucleotide sequences are identical. DNA from leaves and styles from genetically diverse almond samples was cloned and sequenced and then analyzed for changes affecting S f -RNase variants. Epigenetic changes in several cytosine residues were detected in a fragment of 4,700 bp of the 5' upstream region of all self-compatible samples of the S f -RNases, differentiating them from all self-incompatible samples of S f -RNases analyzed. This is the first report of DNA methylation in a Rosaceae species and appears to be strongly associated with inactivation of the S f allele. Results facilitate an understanding of the evolution of self-compatibility/self-incompatibility in almond and other Prunus species, and suggest novel approaches for future crop improvement.

  19. Partial genetic suppression of a loss-of-function mutant of the neuronal ceroid lipofuscinosis-associated protease TPP1 in Dictyostelium discoideum

    Directory of Open Access Journals (Sweden)

    Jonathan E. Phillips

    2015-02-01

    Full Text Available Neuronal ceroid lipofuscinosis (NCL is the most common childhood-onset neurodegenerative disease. NCL is inevitably fatal, and there is currently no treatment available. Children with NCL show a progressive decline in movement, vision and mental abilities, and an accumulation of autofluorescent deposits in neurons and other cell types. Late-infantile NCL is caused by mutations in the lysosomal protease tripeptidyl peptidase 1 (TPP1. TPP1 cleaves tripeptides from the N-terminus of proteins in vitro, but little is known about the physiological function of TPP1. TPP1 shows wide conservation in vertebrates but it is not found in Drosophila, Caenorhabditis elegans or Saccharomyces cerevisiae. Here, we characterize ddTpp1, a TPP1 ortholog present in the social amoeba Dictyostelium discoideum. Lysates from cells lacking ddTpp1 show a reduced but not abolished ability to cleave a TPP1 substrate, suggesting that other Dictyostelium enzymes can perform this cleavage. ddTpp1 and human TPP1 localize to the lysosome in Dictyostelium, indicating conserved function and trafficking. Cells that lack ddTpp1 show precocious multicellular development and a reduced ability to form spores during development. When cultured in autophagy-stimulating conditions, cells lacking ddTpp1 rapidly decrease in size and are less viable than wild-type cells, suggesting that one function of ddTpp1 could be to limit autophagy. Cells that lack ddTpp1 exhibit strongly impaired development in the presence of the lysosome-perturbing drug chloroquine, and this phenotype can be suppressed through a secondary mutation in the gene that we name suppressor of tpp1− A (stpA, which encodes a protein with some similarity to mammalian oxysterol-binding proteins (OSBPs. Taken together, these results suggest that targeting specific proteins could be a viable way to suppress the effects of loss of TPP1 function.

  20. Clinical Expression and New SPINK5 Splicing Defects in Netherton Syndrome : Unmasking a Frequent Founder Synonymous Mutation and Unconventional Intronic Mutations

    NARCIS (Netherlands)

    Lacroix, Matthieu; Lacaze-Buzy, Laetitia; Furio, Laetitia; Tron, Elodie; Valari, Manthoula; Van der Wier, Gerda; Bodemer, Christine; Bygum, Anette; Bursztejn, Anne-Claire; Gaitanis, George; Paradisi, Mauro; Stratigos, Alexander; Weibel, Lisa; Deraison, Celine; Hovnanian, Alain

    Netherton syndrome (NS) is a severe skin disease caused by loss-of-function mutations in SPINK5 (serine protease inhibitor Kazal-type 5) encoding the serine protease inhibitor LEKTI (lympho-epithelial Kazal type-related inhibitor). Here, we disclose new SPINK5 defects in 12 patients, who presented a

  1. A Loss-of-Function Screen for Phosphatases that Regulate Neurite Outgrowth Identifies PTPN12 as a Negative Regulator of TrkB Tyrosine Phosphorylation

    DEFF Research Database (Denmark)

    Ambjørn, Malene; Dubreuil, Véronique; Miozzo, Federico

    2013-01-01

    Alterations in function of the neurotrophin BDNF are associated with neurodegeneration, cognitive decline, and psychiatric disorders. BDNF promotes axonal outgrowth and branching, regulates dendritic tree morphology and is important for axonal regeneration after injury, responses that largely...... that phosphatases belong to multiple independently evolved families, which are rarely studied together. We undertook a loss-of-function RNA-interference-based screen of virtually all known (254) human phosphatases to understand their function in BDNF/TrkB-mediated neurite outgrowth in differentiated SH-SY5Y cells....... This approach identified phosphatases from diverse families, which either positively or negatively modulate BDNF-TrkB-mediated neurite outgrowth, and most of which have little or no previously established function related to NT signaling. "Classical" protein tyrosine phosphatases (PTPs) accounted for 13...

  2. The plant pathogen Pseudomonas syringae pv. tomato is genetically monomorphic and under strong selection to evade tomato immunity.

    Directory of Open Access Journals (Sweden)

    Rongman Cai

    2011-08-01

    Full Text Available Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain.

  3. Wolfram syndrome-associated mutations lead to instability and proteasomal degradation of wolframin.

    Science.gov (United States)

    Hofmann, Sabine; Bauer, Matthias F

    2006-07-10

    Wolfram syndrome is caused by mutations in WFS1 encoding wolframin, a polytopic membrane protein of the endoplasmic reticulum. Here, we investigated the molecular pathomechanisms of four missense and two truncating mutations in WFS1. Expression in COS-7 cells as well as direct analysis of patient cells revealed that WFS1 mutations lead to drastically reduced steady-state levels of wolframin. All mutations resulted in highly unstable proteins which were delivered to proteasomal degradation. No wolframin aggregates were found in patient cells suggesting that Wolfram syndrome is not a disease of protein aggregation. Rather, WFS1 mutations cause loss-of-function by cellular depletion of wolframin.

  4. Functional analysis of HNPCC-related missense mutations in MSH2

    DEFF Research Database (Denmark)

    Lützen, Anne; de Wind, Niels; Georgijevic, Dubravka

    2008-01-01

    Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant...... proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins...

  5. The Mutation P.T613a in the Pore Helix of the Kv 11.1 Potassium Channel is Associated with Long Qt Syndrome

    DEFF Research Database (Denmark)

    Poulsen, Kristian L; Hotait, Mostafa; Calloe, Kirstine

    2015-01-01

    BACKGROUND: Loss-of-function mutations in the voltage gated potassium channel Kv 11.1 have been associated with the Long QT Syndrome (LQTS) type 2. We identified the p.T613A mutation in Kv 11.1 in a family with LQTS. T613A is located in the outer part of the pore helix, a structure that is involved...

  6. Loss-of-Function KCNE2 Variants: True Monogenic Culprits of Long-QT Syndrome or Proarrhythmic Variants Requiring Secondary Provocation?

    NARCIS (Netherlands)

    Roberts, Jason D.; Krahn, Andrew D.; Ackerman, Michael J.; Rohatgi, Ram K.; Moss, Arthur J.; Nazer, Babak; Tadros, Rafik; Gerull, Brenda; Sanatani, Shubhayan; Wijeyeratne, Yanushi D.; Baruteau, Alban-Elouen; Muir, Alison R.; Pang, Benjamin; Cadrin-Tourigny, Julia; Talajic, Mario; Rivard, Lena; Tester, David J.; Liu, Taylor; Whitman, Isaac R.; Wojciak, Julianne; Conacher, Susan; Gula, Lorne J.; Leong-Sit, Peter; Manlucu, Jaimie; Green, Martin S.; Hamilton, Robert; Healey, Jeff S.; Lopes, Coeli M.; Behr, Elijah R.; Wilde, Arthur A.; Gollob, Michael H.; Scheinman, Melvin M.

    2017-01-01

    Insight into type 6 long-QT syndrome (LQT6), stemming from mutations in the KCNE2-encoded voltage-gated channel β-subunit, is limited. We sought to further characterize its clinical phenotype. Individuals with reported pathogenic KCNE2 mutations identified during arrhythmia evaluation were collected

  7. A deletion mutation in GDF9 in sisters with spontaneous DZ twins.

    NARCIS (Netherlands)

    Montgomery, GW; Zhao, Z.Z.; Marsh, A.J.; Mayne, R.; Treloar, S.A.; James, M.; Martin, N.G.; Boomsma, D.I.; Duffy, DL

    2004-01-01

    A loss of function mutation in growth differentiation factor 9 (GDF9) in sheep causes increased ovulation rate and infertility in a dosage-sensitive manner. Spontaneous dizygotic (DZ) twinning in the human is under genetic control and women with a history of DZ twinning have an increased incidence

  8. Mutations in Thyroid Hormone Transporter MCT8: genotype, function and phenotype

    NARCIS (Netherlands)

    J. Jansen (Jurgen)

    2008-01-01

    textabstractThe studies presented in this thesis demonstrate that MCT8 is a transmembrane protein that facilitates both in- and efflux of thyroid hormone. MCT8 function is crucial for normal neurological development, as loss-of-function mutations are associated with severe psychomotor retardation.

  9. Hypogonadotropic Hypogonadism due to Novel FGFR1 Mutations.

    Science.gov (United States)

    Akkuş, Gamze; Kotan, Leman Damla; Durmaz, Erdem; Mengen, Eda; Turan, İhsan; Ulubay, Ayça; Gürbüz, Fatih; Yüksel, Bilgin; Tetiker, Tamer; Topaloğlu, A Kemal

    2017-06-01

    The underlying genetic etiology of hypogonadotropic hypogonadism (HH) is heterogeneous. Fibroblast growth factor signaling is pivotal in the ontogeny of gonadotropin-releasing hormone neurons. Loss-of-function mutations in FGFR1 gene cause variable HH phenotypes encompassing pubertal delay to idiopathic HH (IHH) or Kallmann syndrome (KS). As FGFR1 mutations are common, recognizing mutations and associated phenotypes may enhance clinical management. Using a candidate gene approach, we screened 52 IHH/KS patients. We identified three novel (IVS3-1G>C and p.W2X, p.R209C) FGFR1 gene mutations. Despite predictive null protein function, patients from the novel mutation families had normosmic IHH without non-reproductive phenotype. These findings further emphasize the great variability of FGFR1 mutation phenotypes in IHH/KS.

  10. Parkinson’s disease in GTP cyclohydrolase 1 mutation carriers

    OpenAIRE

    Mencacci, Niccolò E.; Isaias, Ioannis U.; Reich, Martin M.; Ganos, Christos; Plagnol, Vincent; Polke, James M.; Bras, Jose; Hersheson, Joshua; Stamelou, Maria; Pittman, Alan M.; Noyce, Alastair J.; Mok, Kin Y.; Opladen, Thomas; Kunstmann, Erdmute; Hodecker, Sybille

    2014-01-01

    GTP cyclohydrolase 1, encoded by the GCH1 gene, is an essential enzyme for dopamine production in nigrostriatal cells. Loss-of-function mutations in GCH1 result in severe reduction of dopamine synthesis in nigrostriatal cells and are the most common cause of DOPA-responsive dystonia, a rare disease that classically presents in childhood with generalized dystonia and a dramatic long-lasting response to levodopa. We describe clinical, genetic and nigrostriatal dopaminergic imaging ([(123)I]N-ω-...

  11. Parkinson's disease in GTP cyclohydrolase 1 mutation carriers.

    OpenAIRE

    Mencacci, N. E.; Isaias, I. U.; Reich, M. M.; Ganos, C.; Plagnol, V.; Polke, J. M.; Bras, J.; Hersheson, J.; Stamelou, M.; Pittman, A. M.; Noyce, A. J.; Mok, K. Y.; Opladen, T.; Kunstmann, E.; Hodecker, S.

    2014-01-01

    GTP cyclohydrolase 1, encoded by the GCH1 gene, is an essential enzyme for dopamine production in nigrostriatal cells. Loss-of-function mutations in GCH1 result in severe reduction of dopamine synthesis in nigrostriatal cells and are the most common cause of DOPA-responsive dystonia, a rare disease that classically presents in childhood with generalized dystonia and a dramatic long-lasting response to levodopa. We describe clinical, genetic and nigrostriatal dopaminergic imaging ([(123)I]N-ω-...

  12. Oxidative Stress Is Not a Major Contributor to Somatic Mitochondrial DNA Mutations

    Science.gov (United States)

    Itsara, Leslie S.; Kennedy, Scott R.; Fox, Edward J.; Yu, Selina; Hewitt, Joshua J.; Sanchez-Contreras, Monica; Cardozo-Pelaez, Fernando; Pallanck, Leo J.

    2014-01-01

    The accumulation of somatic mitochondrial DNA (mtDNA) mutations is implicated in aging and common diseases of the elderly, including cancer and neurodegenerative disease. However, the mechanisms that influence the frequency of somatic mtDNA mutations are poorly understood. To develop a simple invertebrate model system to address this matter, we used the Random Mutation Capture (RMC) assay to characterize the age-dependent frequency and distribution of mtDNA mutations in the fruit fly Drosophila melanogaster. Because oxidative stress is a major suspect in the age-dependent accumulation of somatic mtDNA mutations, we also used the RMC assay to explore the influence of oxidative stress on the somatic mtDNA mutation frequency. We found that many of the features associated with mtDNA mutations in vertebrates are conserved in Drosophila, including a comparable somatic mtDNA mutation frequency (∼10−5), an increased frequency of mtDNA mutations with age, and a prevalence of transition mutations. Only a small fraction of the mtDNA mutations detected in young or old animals were G∶C to T∶A transversions, a signature of oxidative damage, and loss-of-function mutations in the mitochondrial superoxide dismutase, Sod2, had no detectable influence on the somatic mtDNA mutation frequency. Moreover, a loss-of-function mutation in Ogg1, which encodes a DNA repair enzyme that removes oxidatively damaged deoxyguanosine residues (8-hydroxy-2′-deoxyguanosine), did not significantly influence the somatic mtDNA mutation frequency of Sod2 mutants. Together, these findings indicate that oxidative stress is not a major cause of somatic mtDNA mutations. Our data instead suggests that somatic mtDNA mutations arise primarily from errors that occur during mtDNA replication. Further studies using Drosophila should aid in the identification of factors that influence the frequency of somatic mtDNA mutations. PMID:24516391

  13. Loss-of-Function KCNE2 Variants: True Monogenic Culprits of Long-QT Syndrome or Proarrhythmic Variants Requiring Secondary Provocation?

    Science.gov (United States)

    Roberts, Jason D; Krahn, Andrew D; Ackerman, Michael J; Rohatgi, Ram K; Moss, Arthur J; Nazer, Babak; Tadros, Rafik; Gerull, Brenda; Sanatani, Shubhayan; Wijeyeratne, Yanushi D; Baruteau, Alban-Elouen; Muir, Alison R; Pang, Benjamin; Cadrin-Tourigny, Julia; Talajic, Mario; Rivard, Lena; Tester, David J; Liu, Taylor; Whitman, Isaac R; Wojciak, Julianne; Conacher, Susan; Gula, Lorne J; Leong-Sit, Peter; Manlucu, Jaimie; Green, Martin S; Hamilton, Robert; Healey, Jeff S; Lopes, Coeli M; Behr, Elijah R; Wilde, Arthur A; Gollob, Michael H; Scheinman, Melvin M

    2017-08-01

    Insight into type 6 long-QT syndrome (LQT6), stemming from mutations in the KCNE2 -encoded voltage-gated channel β-subunit, is limited. We sought to further characterize its clinical phenotype. Individuals with reported pathogenic KCNE2 mutations identified during arrhythmia evaluation were collected from inherited arrhythmia clinics and the Rochester long-QT syndrome (LQTS) registry. Previously reported LQT6 cases were identified through a search of the MEDLINE database. Clinical features were assessed, while reported KCNE2 mutations were evaluated for genotype-phenotype segregation and classified according to the contemporary American College of Medical Genetics guidelines. Twenty-seven probands possessed reported pathogenic KCNE2 mutations, while a MEDLINE search identified 17 additional LQT6 cases providing clinical and genetic data. Sixteen probands had normal resting QTc values and only developed QT prolongation and malignant arrhythmias after exposure to QT-prolonging stressors, 10 had other LQTS pathogenic mutations, and 10 did not have an LQTS phenotype. Although the remaining 8 subjects had an LQTS phenotype, evidence suggested that the KCNE2 variant was not the underlying culprit. The collective frequency of KCNE2 variants implicated in LQT6 in the Exome Aggregation Consortium database was 1.4%, in comparison with a 0.0005% estimated clinical prevalence for LQT6. On the basis of clinical phenotype, the high allelic frequencies of LQT6 mutations in the Exome Aggregation Consortium database, and absence of previous documentation of genotype-phenotype segregation, our findings suggest that many KCNE2 variants, and perhaps all, have been erroneously designated as LQTS-causative mutations. Instead, KCNE2 variants may confer proarrhythmic susceptibility when provoked by additional environmental/acquired or genetic factors, or both. © 2017 American Heart Association, Inc.

  14. Very mild features of dysequilibrium syndrome associated with a novel VLDLR missense mutation.

    Science.gov (United States)

    Micalizzi, Alessia; Moroni, Isabella; Ginevrino, Monia; Biagini, Tommaso; Mazza, Tommaso; Romani, Marta; Valente, Enza Maria

    2016-07-01

    Dysequilibrium syndrome (DES) is a non-progressive congenital ataxia characterized by severe intellectual deficit, truncal ataxia and markedly delayed, quadrupedal or absent ambulation. Recessive loss-of-function mutations in the very low density lipoprotein receptor (VLDLR) gene represent the most common cause of DES. Only two families have been reported harbouring homozygous missense mutations, both with a similarly severe phenotype. We report an Italian girl with very mild DES caused by the novel homozygous VLDLR missense mutation p.(C419Y). This unusually benign phenotype possibly relates to a less disruptive effect of the mutation, falling within a domain (EGF-B) not predicted as crucial for the protein function.

  15. Evidence of a tick RNAi pathway by comparative genomics and reverse genetics screen of targets with known loss-of-function phenotypes in Drosophila

    Directory of Open Access Journals (Sweden)

    Kurscheid Sebastian

    2009-03-01

    Full Text Available Abstract Background The Arthropods are a diverse group of organisms including Chelicerata (ticks, mites, spiders, Crustacea (crabs, shrimps, and Insecta (flies, mosquitoes, beetles, silkworm. The cattle tick, Rhipicephalus (Boophilus microplus, is an economically significant ectoparasite of cattle affecting cattle industries world wide. With the availability of sequence reads from the first Chelicerate genome project (the Ixodes scapularis tick and extensive R. microplus ESTs, we investigated evidence for putative RNAi proteins and studied RNA interference in tick cell cultures and adult female ticks targeting Drosophila homologues with known cell viability phenotype. Results We screened 13,643 R. microplus ESTs and I. scapularis genome reads to identify RNAi related proteins in ticks. Our analysis identified 31 RNAi proteins including a putative tick Dicer, RISC associated (Ago-2 and FMRp, RNA dependent RNA polymerase (EGO-1 and 23 homologues implicated in dsRNA uptake and processing. We selected 10 R. microplus ESTs with >80% similarity to D. melanogaster proteins associated with cell viability for RNAi functional screens in both BME26 R. microplus embryonic cells and female ticks in vivo. Only genes associated with proteasomes had an effect on cell viability in vitro. In vivo RNAi showed that 9 genes had significant effects either causing lethality or impairing egg laying. Conclusion We have identified key RNAi-related proteins in ticks and along with our loss-of-function studies support a functional RNAi pathway in R. microplus. Our preliminary studies indicate that tick RNAi pathways may differ from that of other Arthropods such as insects.

  16. GRK2 protein-mediated transphosphorylation contributes to loss of function of μ-opioid receptors induced by neuropeptide FF (NPFF2) receptors.

    Science.gov (United States)

    Moulédous, Lionel; Froment, Carine; Dauvillier, Stéphanie; Burlet-Schiltz, Odile; Zajac, Jean-Marie; Mollereau, Catherine

    2012-04-13

    Neuropeptide FF (NPFF) interacts with specific receptors to modulate opioid functions in the central nervous system. On dissociated neurons and neuroblastoma cells (SH-SY5Y) transfected with NPFF receptors, NPFF acts as a functional antagonist of μ-opioid (MOP) receptors by attenuating the opioid-induced inhibition of calcium conductance. In the SH-SY5Y model, MOP and NPFF(2) receptors have been shown to heteromerize. To understand the molecular mechanism involved in the anti-opioid activity of NPFF, we have investigated the phosphorylation status of the MOP receptor using phospho-specific antibody and mass spectrometry. Similarly to direct opioid receptor stimulation, activation of the NPFF(2) receptor by [D-Tyr-1-(NMe)Phe-3]NPFF (1DMe), an analog of NPFF, induced the phosphorylation of Ser-377 of the human MOP receptor. This heterologous phosphorylation was unaffected by inhibition of second messenger-dependent kinases and, contrarily to homologous phosphorylation, was prevented by inactivation of G(i/o) proteins by pertussis toxin. Using siRNA knockdown we could demonstrate that 1DMe-induced Ser-377 cross-phosphorylation and MOP receptor loss of function were mediated by the G protein receptor kinase GRK2. In addition, mass spectrometric analysis revealed that the phosphorylation pattern of MOP receptors was qualitatively similar after treatment with the MOP agonist Tyr-D-Ala-Gly (NMe)-Phe-Gly-ol (DAMGO) or after treatment with the NPFF agonist 1DMe, but the level of multiple phosphorylation was more intense after DAMGO. Finally, NPFF(2) receptor activation was sufficient to recruit β-arrestin2 to the MOP receptor but not to induce its internalization. These data show that NPFF-induced heterologous desensitization of MOP receptor signaling is mediated by GRK2 and could involve transphosphorylation within the heteromeric receptor complex.

  17. Sick sinus syndrome, progressive cardiac conduction disease, atrial flutter and ventricular tachycardia caused by a novel SCN5A mutation

    DEFF Research Database (Denmark)

    Holst, Anders G; Liang, Bo; Jespersen, Thomas

    2010-01-01

    Mutations in the cardiac sodium channel encoded by the gene SCN5A can result in a wide array of phenotypes. We report a case of a young male with a novel SCN5A mutation (R121W) afflicted by sick sinus syndrome, progressive cardiac conduction disorder, atrial flutter and ventricular tachycardia. His...... father carried the same mutation, but had a milder phenotype, presenting with progressive cardiac conduction later in life. The mutation was found to result in a loss-of-function in the sodium current. In conclusion, the same SCN5A mutation can result in a wide array of clinical phenotypes and perhaps...

  18. The Phenotype Characteristics of Type-13 Long QT Syndrome with mutation in KCNJ5 (Kir3.4-G387R)

    DEFF Research Database (Denmark)

    Wang, Fan; Liu, Jinqiu; Hong, Li

    2013-01-01

    Long QT syndrome type 13 (LQT13) is caused by loss-of-function mutation in the KCNJ5-encoded cardiac G-protein coupled inward rectifier potassium channel Kir3.4. The electrocardiographic (ECG) features of LQT13 are not described yet.......Long QT syndrome type 13 (LQT13) is caused by loss-of-function mutation in the KCNJ5-encoded cardiac G-protein coupled inward rectifier potassium channel Kir3.4. The electrocardiographic (ECG) features of LQT13 are not described yet....

  19. Stepwise decrease in daptomycin susceptibility in clinical Staphylococcus aureus isolates associated with an initial mutation in rpoB and a compensatory inactivation of the clpX gene

    DEFF Research Database (Denmark)

    Bæk, Kristoffer Torbjørn; Thøgersen, Louise; Mogensen, René G.

    2015-01-01

    , reduced expression of virulence traits, induced expression of the stress-associated transcriptional regulator, Spx, and slow growth. A subsequent acquired loss-of-function mutation in clpX partly alleviated the growth defect conferred by the rpoB mutation without changing antibiotic susceptibility...

  20. Loss of function of KIAA2022 causes mild to severe intellectual disability with an autism spectrum disorder and impairs neurite outgrowth

    NARCIS (Netherlands)

    Maldergem, L. van; Hou, Q.; Kalscheuer, V.M.M.; Rio, M. del; Doco-Fenzy, M.; Medeira, A.; Brouwer, A.P.M. de; Cabrol, C.; Haas, S.A.; Cacciagli, P.; Moutton, S.; Landais, E.; Motte, J.; Colleaux, L.; Bonnet, C.; Villard, L.; Dupont, J.; Man, H.Y.

    2013-01-01

    Existence of a discrete new X-linked intellectual disability (XLID) syndrome due to KIAA2022 deficiency was questioned by disruption of KIAA2022 by an X-chromosome pericentric inversion in a XLID family we reported in 2004. Three additional families with likely pathogenic KIAA2022 mutations were

  1. Loss of function of Slc20a2 associated with familial idiopathic Basal Ganglia calcification in humans causes brain calcifications in mice

    DEFF Research Database (Denmark)

    Jensen, N.; Schroder, H. D.; Hejbol, E. K.

    2013-01-01

    Familial idiopathic basal ganglia calcification (FIBGC) is a neurodegenerative disorder with neuropsychiatric and motor symptoms. Deleterious mutations in SLC20A2, encoding the type III sodium-dependent phosphate transporter 2 (PiT2), were recently linked to FIBGC in almost 50% of the families...... reported worldwide. Here, we show that knockout of Slc20a2 in mice causes calcifications in the thalamus, basal ganglia, and cortex, demonstrating that reduced PiT2 expression alone can cause brain calcifications....

  2. Chk1/2 inhibition overcomes the cisplatin resistance of head and neck cancer cells secondary to the loss of functional p53

    Science.gov (United States)

    Gadhikar, Mayur A.; Sciuto, Maria Rita; Alves, Marcus Vinicius Ortega; Pickering, Curtis R.; Osman, Abdullah A.; Neskey, David M.; Zhao, Mei; Fitzgerald, Alison L.; Myers, Jeffrey N.; Frederick, Mitchell J

    2014-01-01

    Despite the use of multimodality therapy employing cisplatin to treat patients with advanced stage head and neck squamous cell carcinoma (HNSCC), there is an unacceptably high rate of treatment failure. TP53 is the most commonly mutated gene in HNSCC, and the impact of p53 mutation on response to cisplatin treatment is poorly understood. Here we show unambiguously that wild type TP53 (wtp53) is associated with sensitivity of HNSCC cells to cisplatin treatment while mutation or loss of TP53 is associated with cisplatin resistance. We also demonstrate that senescence is the major cellular response to cisplatin in wtp53 HNSCC cells and that cisplatin resistance in p53 null or mutant TP53 cells is due to their lack of senescence. Given the dependence on Chk1/2 kinases to mediate the DNA damage response in p53 deficient cells, there is potential to exploit this to therapeutic advantage through targeted inhibition of the Chk1/2 kinases. Treatment of p53 deficient HNSCC cells with the Chk inhibitor AZD7762 sensitizes them to cisplatin through induction of mitotic cell death. This is the first report demonstrating the ability of a Chk kinase inhibitor to sensitize TP53-deficient HNSCC to cisplatin in a synthetic lethal manner, which has significance given the frequency of TP53 mutations in this disease and because cisplatin has become part of standard therapy for aggressive HNSCC tumors. These pre-clinical data provide evidence that a personalized approach to the treatment of HNSCC based on Chk inhibition in p53 mutant tumors may be feasible. PMID:23839309

  3. Red hair--a desirable mutation?

    Science.gov (United States)

    Ha, Thomas; Rees, Jonathan L

    2002-07-01

    Red hair is one of the most striking variants of human hair coloration and has historically been of profound social importance. Red hair in man is due to certain loss of function mutations of one of the peptide products of the pro-opiomelanocortin (POMC) gene, the melanocortin-1 receptor (MC1R, MIM 155555). Such functional mutations enable the melanocyte to produce red-yellow pheomelanin in preference to the default, black-brown eumelanin. This paper reviews the path of discovery of the MC1R in control of animal coat colour, the subsequent role of MC1R in human physiology and possibly wider role of MC1R in human skin carcinogenesis and human development through history.

  4. Succinate-CoA ligase deficiency due to mutations in SUCLA2 and SUCLG1

    DEFF Research Database (Denmark)

    Carrozzo, Rosalba; Verrigni, Daniela; Rasmussen, Magnhild

    2016-01-01

    for SUCLA2 and 20 months for SUCLG1. Notable clinical differences between the two groups were hepatopathy, found in 38% of SUCLG1 cases but not in SUCLA2 cases, and hypertrophic cardiomyopathy which was not reported in SUCLA2 patients, but documented in 14% of cases with SUCLG1 mutations. Long survival...... mutations compared to loss-of-function mutations. Hypertrophic cardiomyopathy and liver involvement was exclusively found in patients with SUCLG1 mutations, whereas epilepsy was much more frequent in patients with SUCLA2 mutations compared to patients with SUCLG1 mutations. The mutation analysis revealed...... insertion, a nonsense mutation and two missense mutations. In the newly-reported SUCLG1 patients, five missense mutations were identified, of which two were novel. The median onset of symptoms was two months for patients with SUCLA2 mutations and at birth for SUCLG1 patients. Median survival was 20 years...

  5. Human Connexin43E42K mutation from a sudden infant death victim leads to impaired ventricular activation and neonatal death in mice.

    Science.gov (United States)

    Lübkemeier, Indra; Bosen, Felicitas; Kim, Jung-Sun; Sasse, Philipp; Malan, Daniela; Fleischmann, Bernd K; Willecke, Klaus

    2015-02-01

    Sudden infant death syndrome (SIDS) describes the sudden, unexplained death of a baby during its first year of age and is the third leading cause of infant mortality. It is assumed that ≤20% of all SIDS cases are because of cardiac arrhythmias resulting from mutations in ion channel proteins. Besides ion channels also cardiac gap junction channels are important for proper conduction of cardiac electric activation. In the mammalian heart Connexin43 (Cx43) is the major gap junction protein expressed in ventricular cardiomyocytes. Recently, a novel Connexin43 loss-of-function mutation (Cx43E42K) was identified in a 2-month-old SIDS victim. We have generated Cx43E42K-expressing mice as a model for SIDS. Heterozygous cardiac-restricted Cx43E42K-mutated mice die neonatally without major cardiac morphological defects. Electrocardiographic recordings of embryonic Cx43+/E42K mice reveal severely disturbed ventricular activation, whereas immunohistochemical analyses show normal localization and expression patterns of gap junctional Connexin43 protein in the Cx43E42K-mutated newborn mouse heart. Because we did not find heterogeneous gap junction loss in Cx43E42K mouse hearts, we conclude that the Cx43E42K gap junction channel creates an arrhythmogenic substrate leading to lethal ventricular arrhythmias. The strong cardiac phenotype of Cx43E42K expressing mice supports the association between the human Cx43E42K mutation and SIDS and indicates that Connexin43 mutations should be considered in future studies when SIDS cases are to be molecularly explained. © 2014 American Heart Association, Inc.

  6. Deep sequencing of uveal melanoma identifies a recurrent mutation in PLCB4

    DEFF Research Database (Denmark)

    Johansson, Peter; Aoude, Lauren G; Wadt, Karin

    2016-01-01

    Next generation sequencing of uveal melanoma (UM) samples has identified a number of recurrent oncogenic or loss-of-function mutations in key driver genes including: GNAQ, GNA11, EIF1AX, SF3B1 and BAP1. To search for additional driver mutations in this tumor type we carried out whole-genome or wh......Next generation sequencing of uveal melanoma (UM) samples has identified a number of recurrent oncogenic or loss-of-function mutations in key driver genes including: GNAQ, GNA11, EIF1AX, SF3B1 and BAP1. To search for additional driver mutations in this tumor type we carried out whole......, instead, a BRCA mutation signature predominated. In addition to mutations in the known UM driver genes, we found a recurrent mutation in PLCB4 (c.G1888T, p.D630Y, NM_000933), which was validated using Sanger sequencing. The identical mutation was also found in published UM sequence data (1 of 56 tumors...

  7. A Novel Mutation in the EDAR Gene Causes Severe Autosomal Recessive Hypohidrotic Ectodermal Dysplasia

    DEFF Research Database (Denmark)

    Henningsen, Emil; Svendsen, Mathias Tiedemann; Lildballe, D. L.

    2014-01-01

    nasal discharge. The girl was the second born child of first-cousin immigrants from Northern Iraq. A novel homozygous mutation (c.84delC) in the EDAR gene was identified. This mutation most likely causes a frameshift in the protein product (p.S29fs*74). This results in abolition of all ectodysplasin......-mediated NF-kB signalling. This complete loss-of-function mutation likely accounts for the severe clinical abnormalities in ectodermal structures in the described patient. (C) 2014 Wiley Periodicals, Inc....

  8. A novel mutation in LAMC3 associated with generalized polymicrogyria of the cortex and epilepsy.

    Science.gov (United States)

    Zambonin, J L; Dyment, D A; Xi, Y; Lamont, R E; Hartley, T; Miller, E; Kerr, M; Boycott, K M; Parboosingh, J S; Venkateswaran, S

    2018-01-01

    Occipital cortical malformation is a rare neurodevelopmental disorder characterized by pachygyria and polymicrogyria of the occipital lobes as well as global developmental delays and seizures. This condition is due to biallelic, loss-of-function mutations in LAMC3 and has been reported in four unrelated families to date. We report an individual with global delays, seizures, and polymicrogyria that extends beyond the occipital lobes and includes the frontal, parietal, temporal, and occipital lobes. Next-generation sequencing identified a homozygous nonsense mutation in LAMC3: c.3190C>T (p.Gln1064*). This finding extends the cortical phenotype associated with LAMC3 mutations.

  9. Functional effects of KCNE3 mutation and its role in the development of Brugada syndrome

    DEFF Research Database (Denmark)

    Delpón, Eva; Cordeiro, Jonathan M; Núñez, Lucía

    2008-01-01

    INTRODUCTION: The Brugada Syndrome (BrS), an inherited syndrome associated with a high incidence of sudden cardiac arrest, has been linked to mutations in four different genes leading to a loss of function in sodium and calcium channel activity. Although the transient outward current (I......(to)) is thought to play a prominent role in the expression of the syndrome, mutations in I(to)-related genes have not been identified as yet. METHODS AND RESULTS: One hundred and five probands with BrS were screened for ion channel gene mutations using single strand conformation polymorphism (SSCP...

  10. A Single Residue Mutation in the Gαq Subunit of the G Protein Complex Causes Blindness in Drosophila

    Directory of Open Access Journals (Sweden)

    Jinguo Cao

    2018-01-01

    Full Text Available Heterotrimeric G proteins play central roles in many signaling pathways, including the phototransduction cascade in animals. However, the degree of involvement of the G protein subunit Gαq is not clear since animals with previously reported strong loss-of-function mutations remain responsive to light stimuli. We recovered a new allele of Gαq in Drosophila that abolishes light response in a conventional electroretinogram assay, and reduces sensitivity in whole-cell recordings of dissociated cells by at least five orders of magnitude. In addition, mutant eyes demonstrate a rapid rate of degeneration in the presence of light. Our new allele is likely the strongest hypomorph described to date. Interestingly, the mutant protein is produced in the eyes but carries a single amino acid change of a conserved hydrophobic residue that has been assigned to the interface of interaction between Gαq and its downstream effector, PLC. Our study has thus uncovered possibly the first point mutation that specifically affects this interaction in vivo.

  11. Overlapping LQT1 and LQT2 phenotype in a patient with long QT syndrome associated with loss-of-function variations in KCNQ1 and KCNH2

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Perez, Guillermo J; Schmitt, Nicole

    2010-01-01

    . The proband (MMRL0362), a 32-year-old female, exhibited multiple ventricular extrasystoles and one syncope. Her ECG (QT interval corrected for heart rate (QTc) = 518ms) showed an LQT2 morphology in leads V4-V6 and LQT1 morphology in leads V1-V2. Genomic DNA was isolated from lymphocytes. All exons and intron...... patch-clamp analysis. In addition, WT or K897T Kv11.1 were also studied by patch clamp. Current-voltage (I-V) relations for V110I showed a significant reduction in both developing and tail current densities compared with WT at potentials >+20 mV (p group), suggesting a reduction......Long QT syndrome (LQTS) is an inherited disorder characterized by prolonged QT intervals and potentially life-threatening arrhythmias. Mutations in 12 different genes have been associated with LQTS. Here we describe a patient with LQTS who has a mutation in KCNQ1 as well as a polymorphism in KCNH2...

  12. A Model of Compound Heterozygous, Loss-of-Function Alleles Is Broadly Consistent with Observations from Complex-Disease GWAS Datasets.

    Directory of Open Access Journals (Sweden)

    Jaleal S Sanjak

    2017-01-01

    Full Text Available The genetic component of complex disease risk in humans remains largely unexplained. A corollary is that the allelic spectrum of genetic variants contributing to complex disease risk is unknown. Theoretical models that relate population genetic processes to the maintenance of genetic variation for quantitative traits may suggest profitable avenues for future experimental design. Here we use forward simulation to model a genomic region evolving under a balance between recurrent deleterious mutation and Gaussian stabilizing selection. We consider multiple genetic and demographic models, and several different methods for identifying genomic regions harboring variants associated with complex disease risk. We demonstrate that the model of gene action, relating genotype to phenotype, has a qualitative effect on several relevant aspects of the population genetic architecture of a complex trait. In particular, the genetic model impacts genetic variance component partitioning across the allele frequency spectrum and the power of statistical tests. Models with partial recessivity closely match the minor allele frequency distribution of significant hits from empirical genome-wide association studies without requiring homozygous effect sizes to be small. We highlight a particular gene-based model of incomplete recessivity that is appealing from first principles. Under that model, deleterious mutations in a genomic region partially fail to complement one another. This model of gene-based recessivity predicts the empirically observed inconsistency between twin and SNP based estimated of dominance heritability. Furthermore, this model predicts considerable levels of unexplained variance associated with intralocus epistasis. Our results suggest a need for improved statistical tools for region based genetic association and heritability estimation.

  13. The sodium-phosphate co-transporter SLC34A2, and pulmonary alveolar microlithiasis: Presentation of an inbred family and a novel truncating mutation in exon 3

    Directory of Open Access Journals (Sweden)

    Marco Favio Michele Vismara

    2015-01-01

    We now report a consanguineous Italian family from Calabria with two affected members segregating alveolar microlithiasis in a recessive fashion. We describe, for the first time, a novel loss of function mutation in the gene coding for NaPi-IIb. A careful description of the clinical phenotype is provided together with technical details for direct sequencing of the gene.

  14. A heterozygous null mutation combined with the G1258A polymorphism of SPINK5 causes impaired LEKTI function and abnormal expression of skin barrier proteins

    NARCIS (Netherlands)

    Di, W.-L.; Hennekam, R. C.; Callard, R. E.; Harper, J. I.

    2009-01-01

    P>Background Loss-of-function mutations in the Kazal-type serine protease inhibitor, LEKTI, encoded by the SPINK5 gene cause the rare autosomal recessive skin disease Netherton syndrome (NS). G1258A polymorphism in SPINK5 may be associated with atopic dermatitis, which shares several clinical

  15. Reduction of antinutritional glucosinolates in Brassica oilseeds by mutation of genes encoding transporters.

    Science.gov (United States)

    Nour-Eldin, Hussam Hassan; Madsen, Svend Roesen; Engelen, Steven; Jørgensen, Morten Egevang; Olsen, Carl Erik; Andersen, Jonathan Sonne; Seynnaeve, David; Verhoye, Thalia; Fulawka, Rudy; Denolf, Peter; Halkier, Barbara Ann

    2017-04-01

    The nutritional value of Brassica seed meals is reduced by the presence of glucosinolates, which are toxic compounds involved in plant defense. Mutation of the genes encoding two glucosinolate transporters (GTRs) eliminated glucosinolates from Arabidopsis thaliana seeds, but translation of loss-of-function phenotypes into Brassica crops is challenging because Brassica is polyploid. We mutated one of seven and four of 12 GTR orthologs and reduced glucosinolate levels in seeds by 60-70% in two different Brassica species (Brassica rapa and Brassica juncea). Reduction in seed glucosinolates was stably inherited over multiple generations and maintained in field trials of two mutant populations at three locations. Successful translation of the gtr loss-of-function phenotype from model plant to two Brassica crops suggests that our transport engineering approach could be broadly applied to reduce seed glucosinolate content in other oilseed crops, such as Camelina sativa or Crambe abyssinica.

  16. Determination of the loss of function complement C4 exon 29 CT insertion using a novel paralog-specific assay in healthy UK and Spanish populations.

    Science.gov (United States)

    Boteva, Lora; Wu, Yee Ling; Cortes-Hernández, Josefina; Martin, Javier; Vyse, Timothy J; Fernando, Michelle M A

    2011-01-01

    Genetic variants resulting in non-expression of complement C4A and C4B genes are common in healthy European populations and have shown association with a number of diseases, most notably the autoimmune disease, systemic lupus erythematosus. The most frequent cause of a C4 "null" allele, following that of C4 gene copy number variation (CNV), is a non-sense mutation arising from a 2 bp CT insertion into codon 1232 of exon 29. Previous attempts to accurately genotype this polymorphism have not been amenable to high-throughput typing, and have been confounded by failure to account for CNV at this locus, as well as by inability to distinguish between paralogs. We have developed a novel, high-throughput, paralog-specific assay to detect the presence and copy number of this polymorphism. We have genotyped healthy cohorts from the United Kingdom (UK) and Spain. Overall, 30/719 (4.17%) individuals from the UK cohort and 8/449 (1.78%) individuals from the Spanish cohort harboured the CT insertion in a C4A gene. A single Spanish individual possessed a C4B CT insertion. There is weak correlation between the C4 CT insertion and flanking MHC polymorphism. Therefore it is important to note that, as with C4 gene CNV, disease-association due to this variant will be missed by current SNP-based genome-wide association strategies.

  17. Loss of function of the tuberous sclerosis 2 tumor suppressor gene results in embryonic lethality characterized by disrupted neuroepithelial growth and development

    Science.gov (United States)

    Rennebeck, Gabriela; Kleymenova, Elena V.; Anderson, Rebecca; Yeung, Raymond S.; Artzt, Karen; Walker, Cheryl L.

    1998-01-01

    Germline defects in the tuberous sclerosis 2 (TSC2) tumor suppressor gene predispose humans and rats to benign and malignant lesions in a variety of tissues. The brain is among the most profoundly affected organs in tuberous sclerosis (TSC) patients and is the site of development of the cortical tubers for which the hereditary syndrome is named. A spontaneous germline inactivation of the Tsc2 locus has been described in an animal model, the Eker rat. We report that the homozygous state of this mutation (Tsc2Ek/Ek) was lethal in mid-gestation (the equivalent of mouse E9.5–E13.5), when Tsc2 mRNA was highly expressed in embryonic neuroepithelium. During this period homozygous mutant Eker embryos lacking functional Tsc2 gene product, tuberin, displayed dysraphia and papillary overgrowth of the neuroepithelium, indicating that loss of tuberin disrupted the normal development of this tissue. Interestingly, there was significant intraspecies variability in the penetrance of cranial abnormalities in mutant embryos: the Long–Evans strain Tsc2Ek/Ek embryos displayed these defects whereas the Fisher 344 homozygous mutant embryos had normal-appearing neuroepithelium. Taken together, our data indicate that the Tsc2 gene participates in normal brain development and suggest the inactivation of this gene may have similar functional consequences in both mature and embryonic brain. PMID:9861021

  18. The genetic basis of Brugada syndrome: a mutation update

    DEFF Research Database (Denmark)

    Hedley, Paula L; Jørgensen, Poul; Schlamowitz, Sarah

    2009-01-01

    of inheritance with an average prevalence of 5:10,000 worldwide. Currently, more than 100 mutations in seven genes have been associated with BrS. Loss-of-function mutations in SCN5A, which encodes the alpha-subunit of the Na(v)1.5 sodium ion channel conducting the depolarizing I(Na) current, causes 15-20% of Br......S cases. A few mutations have been described in GPD1L, which encodes glycerol-3-phosphate dehydrogenase-1 like protein; CACNA1C, which encodes the alpha-subunit of the Ca(v)1.2 ion channel conducting the depolarizing I(L,Ca) current; CACNB2, which encodes the stimulating beta2-subunit of the Ca(v)1.2 ion...

  19. Voltage-sensor mutations in channelopathies of skeletal muscle

    Science.gov (United States)

    Cannon, Stephen C

    2010-01-01

    Mutations of voltage-gated ion channels cause several channelopathies of skeletal muscle, which present clinically with myotonia, periodic paralysis, or a combination of both. Expression studies have revealed both loss-of-function and gain-of-function defects for the currents passed by mutant channels. In many cases, these functional changes could be mechanistically linked to the defects of fibre excitability underlying myotonia or periodic paralysis. One remaining enigma was the basis for depolarization-induced weakness in hypokalaemic periodic paralysis (HypoPP) arising from mutations in either sodium or calcium channels. Curiously, 14 of 15 HypoPP mutations are at arginines in S4 voltage sensors, and recent observations show that these substitutions support an alternative pathway for ion conduction, the gating pore, that may be the source of the aberrant depolarization during an attack of paralysis. PMID:20156847

  20. Sequence divergence and loss-of-function phenotypes of S locus F-box brothers genes are consistent with non-self recognition by multiple pollen determinants in self-incompatibility of Japanese pear (Pyrus pyrifolia).

    Science.gov (United States)

    Kakui, Hiroyuki; Kato, Masaki; Ushijima, Koichiro; Kitaguchi, Miyoko; Kato, Shu; Sassa, Hidenori

    2011-12-01

    The S-RNase-based gametophytic self-incompatibility (SI) of Rosaceae, Solanaceae, and Plantaginaceae is controlled by at least two tightly linked genes located at the complex S locus; the highly polymorphic S-RNase for pistil specificity and the F-box gene (SFB/SLF) for pollen. Self-incompatibility in Prunus (Rosaceae) is considered to represent a 'self recognition by a single factor' system, because loss-of-function of SFB is associated with self-compatibility, and allelic divergence of SFB is high and comparable to that of S-RNase. In contrast, Petunia (Solanaceae) exhibits 'non-self recognition by multiple factors'. However, the distribution of 'self recognition' and 'non-self recognition' SI systems in different taxa is not clear. In addition, in 'non-self recognition' systems, a loss-of-function phenotype of pollen S is unknown. Here we analyze the divergence of SFBB genes, the multiple pollen S candidates, of a rosaceous plant Japanese pear (Pyrus pyrifolia) and show that intrahaplotypic divergence is high and comparable to the allelic diversity of S-RNase while interhaplotypic divergence is very low. Next, we analyzed loss-of-function of the SFBB1 type gene. Genetic analysis showed that pollen with the mutant haplotype S(4sm) lacking SFBB1-S(4) is rejected by pistils with an otherwise compatible S(1) while it is accepted by other non-self pistils. We found that the S(5) haplotype encodes a truncated SFBB1 protein, even though S(5) pollen is accepted normally by pistils with S(1) and other non-self haplotypes. These findings suggest that Japanese pear has a 'non-self recognition by multiple factors' SI system, although it is a species of Rosaceae to which Prunus also belongs. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  1. Identification of a loss-of-function inducible degrader of the low-density lipoprotein receptor variant in individuals with low circulating low-density lipoprotein.

    Science.gov (United States)

    Sorrentino, Vincenzo; Fouchier, Sigrid W; Motazacker, Mohammad M; Nelson, Jessica K; Defesche, Joep C; Dallinga-Thie, Geesje M; Kastelein, John J P; Kees Hovingh, G; Zelcer, Noam

    2013-05-01

    Recent genome-wide association studies suggest that IDOL (also known as MYLIP) contributes to variation in circulating levels of low-density lipoprotein cholesterol (LDL-C). IDOL, an E3-ubiquitin ligase, is a recently identified post-transcriptional regulator of LDLR abundance. Briefly, IDOL promotes degradation of the LDLR thereby limiting LDL uptake. Yet the exact role of IDOL in human lipoprotein metabolism is unclear. Therefore, this study aimed at identifying and functionally characterizing IDOL variants in the Dutch population and to assess their contribution to circulating levels of LDL-C. We sequenced the IDOL coding region in 677 individuals with LDL-C above the 95th percentile adjusted for age and gender (high-LDL-C cohort) in which no mutations in the LDLR, APOB, and PCSK9 could be identified. In addition, IDOL was sequenced in 560 individuals with baseline LDL-C levels below the 20th percentile adjusted for age and gender (low-LDL-C cohort). We identified a total of 14 IDOL variants (5 synonymous, 8 non-synonymous, and 1 non-sense). Functional characterization of these variants demonstrated that the p.Arg266X variant represents a complete loss of IDOL function unable to promote ubiquitylation and subsequent degradation of the LDLR. Consistent with loss of IDOL function, this variant was identified in individuals with low circulating LDL-C. Our results support the notion that IDOL contributes to variation in circulating levels of LDL-C. Strategies to inhibit IDOL activity may therefore provide a novel therapeutic venue to treating dyslipidaemia.

  2. De novo microdeletions and point mutations affecting SOX2 in three individuals with intellectual disability but without major eye malformations.

    Science.gov (United States)

    Dennert, Nicola; Engels, Hartmut; Cremer, Kirsten; Becker, Jessica; Wohlleber, Eva; Albrecht, Beate; Ehret, Julia K; Lüdecke, Hermann-Josef; Suri, Mohnish; Carignani, Giulia; Renieri, Alessandra; Kukuk, Guido M; Wieland, Thomas; Andrieux, Joris; Strom, Tim M; Wieczorek, Dagmar; Dieux-Coëslier, Anne; Zink, Alexander M

    2017-02-01

    Loss-of-function mutations and deletions of the SOX2 gene are known to cause uni- and bilateral anophthalmia and microphthalmia as well as related disorders such as anophthalmia-esophageal-genital syndrome. Thus, anophthalmia/microphthalmia is the primary indication for targeted, "phenotype first" analyses of SOX2. However, SOX2 mutations are also associated with a wide range of non-ocular abnormalities, such as postnatal growth retardation, structural brain anomalies, hypogenitalism, and developmental delay. The present report describes three patients without anophthalmia/microphthalmia and loss-of-function mutations or microdeletions of SOX2 who had been investigated in a "genotype first" manner due to intellectual disability/developmental delay using whole exome sequencing or chromosomal microarray analyses. This result prompted us to perform SOX2 Sanger sequencing in 192 developmental delay/intellectual disability patients without anophthalmia or microphthalmia. No additional SOX2 loss-of-function mutations were detected in this cohort, showing that SOX2 is clearly not a major cause of intellectual disability without anophthalmia/microphthalmia. In our three patients and four further, reported "genotype first" SOX2 microdeletion patients, anophthalmia/microphthalmia was present in less than half of the patients. Thus, SOX2 is another example of a gene whose clinical spectrum is broadened by the generation of "genotype first" findings using hypothesis-free, genome-wide methods. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Novel GABRG2 mutations cause familial febrile seizures

    Science.gov (United States)

    Boillot, Morgane; Morin-Brureau, Mélanie; Picard, Fabienne; Weckhuysen, Sarah; Lambrecq, Virginie; Minetti, Carlo; Striano, Pasquale; Zara, Federico; Iacomino, Michele; Ishida, Saeko; An-Gourfinkel, Isabelle; Daniau, Mailys; Hardies, Katia; Baulac, Michel; Dulac, Olivier; Leguern, Eric; Nabbout, Rima

    2015-01-01

    Objective: To identify the genetic cause in a large family with febrile seizures (FS) and temporal lobe epilepsy (TLE) and subsequently search for additional mutations in a cohort of 107 families with FS, with or without epilepsy. Methods: The cohort consisted of 1 large family with FS and TLE, 64 smaller French families recruited through a national French campaign, and 43 Italian families. Molecular analyses consisted of whole-exome sequencing and mutational screening. Results: Exome sequencing revealed a p.Glu402fs*3 mutation in the γ2 subunit of the GABAA receptor gene (GABRG2) in the large family with FS and TLE. Three additional nonsense and frameshift GABRG2 mutations (p.Arg136*, p.Val462fs*33, and p.Pro59fs*12), 1 missense mutation (p.Met199Val), and 1 exonic deletion were subsequently identified in 5 families of the follow-up cohort. Conclusions: We report GABRG2 mutations in 5.6% (6/108) of families with FS, with or without associated epilepsy. This study provides evidence that GABRG2 mutations are linked to the FS phenotype, rather than epilepsy, and that loss-of-function of GABAA receptor γ2 subunit is the probable underlying pathogenic mechanism. PMID:27066572

  4. Early onset obesity and adrenal insufficiency associated with a homozygous POMC mutation

    Directory of Open Access Journals (Sweden)

    Eng Christine M

    2011-07-01

    Full Text Available Abstract Isolated hypocortisolism due to ACTH deficiency is a rare condition that can be caused by homozygous or compound heterozygous mutations in the gene encoding proopiomelanocortin (POMC. Loss of function mutations of POMC gene typically results in adrenal insufficiency, obesity and red hair. We describe an 18 month old Hispanic female with congenital adrenal insufficiency, a novel POMC mutation and atypical clinical features. The patient presented at the age of 9 months with hypoglycemia and the endocrine evaluation resulted in a diagnosis of ACTH deficiency. She developed extreme weight gain prompting sequence analysis of POMC, which revealed a homozygous c.231C > A change which is predicted to result in a premature termination codon. The case we report had obesity, hypocortisolism but lacked red hair which is typical for subjects with POMC mutations. Mutations of POMC should be considered in individuals with severe early onset obesity and adrenal insufficiency even when they lack the typical pigmentary phenotype.

  5. Ovarian aromatase loss-of-function mutant medaka undergo ovary degeneration and partial female-to-male sex reversal after puberty.

    Science.gov (United States)

    Nakamoto, Masatoshi; Shibata, Yasushi; Ohno, Kaoru; Usami, Takeshi; Kamei, Yasuhiro; Taniguchi, Yoshihito; Todo, Takeshi; Sakamoto, Takashi; Young, Graham; Swanson, Penny; Naruse, Kiyoshi; Nagahama, Yoshitaka

    2018-01-15

    Although estrogens have been generally considered to play a critical role in ovarian differentiation in non-mammalian vertebrates, the specific functions of estrogens during ovarian differentiation remain unclear. We isolated two mutants with premature stops in the ovarian aromatase (cyp19a1) gene from an N-ethyl-N-nitrosourea-based gene-driven mutagenesis library of the medaka, Oryzias latipes. In XX mutants, gonads first differentiated into normal ovaries containing many ovarian follicles that failed to accumulate yolk. Subsequently, ovarian tissues underwent extensive degeneration, followed by the appearance of testicular tissues on the dorsal side of ovaries. In the newly formed testicular tissue, strong expression of gsdf was detected in sox9a2-positive somatic cells surrounding germline stem cells suggesting that gsdf plays an important role in testicular differentiation during estrogen-depleted female-to-male sex reversal. We conclude that endogenous estrogens synthesized after fertilization are not essential for early ovarian differentiation but are critical for the maintenance of adult ovaries. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. TDP-43 Loss-of-Function Causes Neuronal Loss Due to Defective Steroid Receptor-Mediated Gene Program Switching in Drosophila

    Directory of Open Access Journals (Sweden)

    Lies Vanden Broeck

    2013-01-01

    Full Text Available TDP-43 proteinopathy is strongly implicated in the pathogenesis of amyotrophic lateral sclerosis and related neurodegenerative disorders. Whether TDP-43 neurotoxicity is caused by a novel toxic gain-of-function mechanism of the aggregates or by a loss of its normal function is unknown. We increased and decreased expression of TDP-43 (dTDP-43 in Drosophila. Although upregulation of dTDP-43 induced neuronal ubiquitin and dTDP-43-positive inclusions, both up- and downregulated dTDP-43 resulted in selective apoptosis of bursicon neurons and highly similar transcriptome alterations at the pupal-adult transition. Gene network analysis and genetic validation showed that both up- and downregulated dTDP-43 directly and dramatically increased the expression of the neuronal microtubule-associated protein Map205, resulting in cytoplasmic accumulations of the ecdysteroid receptor (EcR and a failure to switch EcR-dependent gene programs from a pupal to adult pattern. We propose that dTDP-43 neurotoxicity is caused by a loss of its normal function.

  7. Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

    Science.gov (United States)

    Nishino, Kohei; Kushima, Misaki; Matsuo, Yuzy; Matsuo, Yasuhiro; Kawamukai, Makoto

    2015-01-01

    Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

  8. Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

    Directory of Open Access Journals (Sweden)

    Kohei Nishino

    Full Text Available Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

  9. Chromosome 11q13.5 variant associated with childhood eczema: an effect supplementary to filaggrin mutations.

    LENUS (Irish Health Repository)

    O'Regan, Grainne M

    2012-02-01

    BACKGROUND: Atopic eczema is a common inflammatory skin disease with multifactorial etiology. The genetic basis is incompletely understood; however, loss of function mutations in the filaggrin gene (FLG) are the most significant and widely replicated genetic risk factor reported to date. The first genome-wide association study in atopic eczema recently identified 2 novel genetic variants in association with eczema susceptibility: a single nucleotide polymorphism on chromosome 11q13.5 (rs7927894) and a single nucleotide polymorphism (rs877776) within the gene encoding hornerin on chromosome 1q21. OBJECTIVE: To test the association of these 2 novel variants with pediatric eczema and to investigate their interaction with FLG null mutations. METHODS: Case-control study to investigate the association of rs7927894, rs877776 and the 4 most prevalent FLG null mutations with moderate-severe eczema in 511 Irish pediatric cases and 1000 Irish controls. Comprehensive testing for interaction between each of the loci was also performed. RESULTS: The association between rs7927894 and atopic eczema was replicated in this population (P = .0025, chi(2) test; odds ratio, 1.27; 95% CI, 1.09-1.49). The 4 most common FLG null variants were strongly associated with atopic eczema (P = 1.26 x 10(-50); combined odds ratio, 5.81; 95% CI, 4.51-7.49). Interestingly, the rs7927894 association was independent of the well-established FLG risk alleles and may be multiplicative in its effect. There was no significant association between rs877776 and pediatric eczema in this study. CONCLUSION: Single nucleotide polymorphism rs7927894 appears to mark a genuine eczema susceptibility locus that will require further elucidation through fine mapping and functional analysis.

  10. Mutations in HNF1A Result in Marked Alterations of Plasma Glycan Profile

    DEFF Research Database (Denmark)

    Thanabalasingham, G.; Huffman, J. E.; Kattla, J. J.

    2013-01-01

    A recent genome-wide association study identified hepatocyte nuclear factor 1-alpha (HNF1A) as a key regulator of fucosylation. We hypothesized that loss-of-function HNF1A mutations causal for maturity-onset diabetes of the young (MOD?) would display altered fucosylation of N-linked glycans on pl...... undetected HNF1A mutations in patients with diabetes. In conclusion, glycan profiles are altered substantially in HNF1A-MODY, and the DG9-glycan index has potential clinical value as a diagnostic biomarker of HNF1A dysfunction. Diabetes 62:1329-1337, 2013...

  11. De novo loss- or gain-of-function mutations in KCNA2 cause epileptic encephalopathy

    DEFF Research Database (Denmark)

    Syrbe, Steffen; Hedrich, Ulrike B S; Riesch, Erik

    2015-01-01

    disability, delayed speech development and sometimes ataxia. Functional studies of the two mutations associated with this phenotype showed almost complete loss of function with a dominant-negative effect. Two further individuals presented with a different and more severe epileptic encephalopathy phenotype....... They carried mutations inducing a drastic gain-of-function effect leading to permanently open channels. These results establish KCNA2 as a new gene involved in human neurodevelopmental disorders through two different mechanisms, predicting either hyperexcitability or electrical silencing of KV1.2-expressing...

  12. Epigenetics and autism spectrum disorder: A report of an autism case with mutation in H1 linker histone HIST1H1e and literature review.

    Science.gov (United States)

    Duffney, Lara J; Valdez, Purnima; Tremblay, Martine W; Cao, Xinyu; Montgomery, Sarah; McConkie-Rosell, Allyn; Jiang, Yong-Hui

    2018-04-27

    Genetic mutations in genes encoding proteins involved in epigenetic machinery have been reported in individuals with autism spectrum disorder (ASD), intellectual disability, congenital heart disease, and other disorders. H1 histone linker protein, the basic component in nucleosome packaging and chromatin organization, has not been implicated in human disease until recently. We report a de novo deleterious mutation of histone cluster 1 H1 family member e (HIST1H1E; c.435dupC; p.Thr146Hisfs*50), encoding H1 histone linker protein H1.4, in a 10-year-old boy with autism and intellectual disability diagnosed through clinical whole exome sequencing. The c.435dupC at the 3' end of the mRNA leads to a frameshift and truncation of the positive charge in the carboxy-terminus of the protein. An expression study demonstrates the mutation leads to reduced protein expression, supporting haploinsufficiency of HIST1H1E protein and loss of function as an underlying mechanism of dysfunction in the brain. Taken together with other recent cases with mutations of HIST1H1E in intellectual disability, the evidence supporting the link to causality in disease is strong. Our finding implicates the deficiency of H1 linker histone protein in autism. The systematic review of candidate genes implicated in ASD revealed that 42 of 215 (19.5%) genes are directly involved in epigenetic regulations and the majority of these genes belong to histone writers, readers, and erasers. While the mechanism of how haploinsufficiency of HIST1H1E causes autism is entirely unknown, our report underscores the importance of further study of the function of this protein and other histone linker proteins in brain development. © 2018 Wiley Periodicals, Inc.

  13. Folliculin mutations are not associated with severe COPD

    Directory of Open Access Journals (Sweden)

    Litonjua Augusto A

    2008-12-01

    Full Text Available Abstract Background Rare loss-of-function folliculin (FLCN mutations are the genetic cause of Birt-Hogg-Dubé syndrome, a monogenic disorder characterized by spontaneous pneumothorax, fibrofolliculomas, and kidney tumors. Loss-of-function folliculin mutations have also been described in pedigrees with familial spontaneous pneumothorax. Because the majority of patients with folliculin mutations have radiographic evidence of pulmonary cysts, folliculin has been hypothesized to contribute to the development of emphysema. To determine whether folliculin sequence variants are risk factors for severe COPD, we genotyped seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax associated folliculin mutations in 152 severe COPD probands participating in the Boston Early-Onset COPD Study. We performed bidirectional resequencing of all 14 folliculin exons in a subset of 41 probands and subsequently genotyped four identified variants in an independent sample of345 COPD subjects from the National Emphysema Treatment Trial (cases and 420 male smokers with normal lung function from the Normative Aging Study (controls. Results None of the seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax mutations were observed in the 152 severe, early-onset COPD probands. Exon resequencing identified 31 variants, including two non-synonymous polymorphisms and two common non-coding polymorphisms. No significant association was observed for any of these four variants with presence of COPD or emphysema-related phenotypes. Conclusion Genetic variation in folliculin does not appear to be a major risk factor for severe COPD. These data suggest that familial spontaneous pneumothorax and COPD have distinct genetic causes, despite some overlap in radiographic characteristics.

  14. Novel FLG null mutations in Korean patients with atopic dermatitis and comparison of the mutational spectra in Asian populations.

    Science.gov (United States)

    Park, Joonhong; Jekarl, Dong Wook; Kim, Yonggoo; Kim, Jiyeon; Kim, Myungshin; Park, Young Min

    2015-09-01

    Filaggrin is essential for the development of the skin barrier. Mutations in the gene encoding filaggrin have been identified as major predisposing factors for atopic disorders. Molecular analysis of the FLG gene in this study showed nine null and one unclassified mutation in 13 of 81 Korean patients with atopic dermatitis (AD): five novel null mutations (i.e. p.S1405*, c.5671_5672delinsTA, p.W1947*, p.G2025* and p.E3070*); four reported null mutations (i.e. c.3321delA, p.S1515*, p.S3296* and p.K4022*); and one unclassified mutation (i.e. c.306delAAAGCACAG). These variants are nonsense, premature termination codon or in-frame deletion expected to cause loss-of-function of FLG. Genotype-phenotype correlation is not obvious in Korean AD patients with FLG null mutations. According to a review of the mutational spectra of the FLG gene in the Asian populations, FLG null mutations appeared to be unique in each population but some mutations such as p.R501*, c.3321delA, p.S1515*, p.S3296* and p.K4022* were commonly found in at least two of the selected Asian populations including Korean, Japanese, Chinese, Singaporean Chinese or Taiwanese. Further investigations on a larger group of Korean AD would be necessary to elucidate its clinical pathogenesis and mutational spectrum related to specific FLG null mutations for AD. © 2015 Japanese Dermatological Association.

  15. GOLGA2, encoding a master regulator of golgi apparatus, is mutated in a patient with a neuromuscular disorder.

    Science.gov (United States)

    Shamseldin, Hanan E; Bennett, Alexis H; Alfadhel, Majid; Gupta, Vandana; Alkuraya, Fowzan S

    2016-02-01

    Golgi apparatus (GA) is a membrane-bound organelle that serves a multitude of critical cellular functions including protein secretion and sorting, and cellular polarity. Many Mendelian diseases are caused by mutations in genes encoding various components of GA. GOLGA2 encodes GM130, a necessary component for the assembly of GA as a single complex, and its deficiency has been found to result in severe cellular phenotypes. We describe the first human patient with a homozygous apparently loss of function mutation in GOLGA2. The phenotype is a neuromuscular disorder characterized by developmental delay, seizures, progressive microcephaly, and muscular dystrophy. Knockdown of golga2 in zebrafish resulted in severe skeletal muscle disorganization and microcephaly recapitulating loss of function human phenotype. Our data suggest an important developmental role of GM130 in humans and zebrafish.

  16. Impact of gain-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) on glucose and lipid homeostasis

    DEFF Research Database (Denmark)

    Foer, D; Zhu, M; Cardone, R L

    2017-01-01

    to impaired glucose and lipid metabolism, we hypothesized that individuals with an HBM-causing mutation in LRP5 would exhibit improved glucose and lipid homeostasis. Since studies in animal models have suggested that Wnt signaling augments insulin secretion, we also examined the effect of Wnt signaling......LRP5 loss-of-function mutations have been shown to cause profound osteoporosis and have been associated with impaired insulin sensitivity and dysregulated lipid metabolism. We hypothesized that gain-of-function mutations in LRP5 would also affect these parameters. We therefore studied individuals...... potentially represents a target for drug discovery in type 2 diabetes and hyperlipidemia. Studies in animal models suggest a physiologic link between LRP5 and glucose and lipid homeostasis; however, whether it plays a similar role in humans is unclear. As current literature links loss-of-function LRP5...

  17. The impact of a single-nucleotide mutation of bgl2 on cellulase induction in a Trichoderma reesei mutant.

    Science.gov (United States)

    Shida, Yosuke; Yamaguchi, Kaori; Nitta, Mikiko; Nakamura, Ayana; Takahashi, Machiko; Kidokoro, Shun-Ichi; Mori, Kazuki; Tashiro, Kosuke; Kuhara, Satoru; Matsuzawa, Tomohiko; Yaoi, Katsuro; Sakamoto, Yasumitsu; Tanaka, Nobutada; Morikawa, Yasushi; Ogasawara, Wataru

    2015-01-01

    The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) produces increased cellulase expression when grown on cellulose or its derivatives as a sole carbon source. It has been believed that β-glucosidases of T. reesei not only metabolize cellobiose but also contribute in the production of inducers of cellulase gene expression by their transglycosylation activity. The cellulase hyper-producing mutant PC-3-7 developed in Japan has enhanced cellulase production ability when cellobiose is used as the inducer. The comparative genomics analysis of PC-3-7 and its parent revealed a single-nucleotide mutation within the bgl2 gene encoding intracellular β-glucosidase II (BGLII/Cel1a), giving rise to an amino acid substitution in PC-3-7, which could potentially account for the enhanced cellulase expression when these strains are cultivated on cellulose and cellobiose. To analyze the effects of the BGLII mutation in cellulase induction, we constructed both a bgl2 revertant and a disruptant. Enzymatic analysis of the transformant lysates showed that the strain expressing mutant BGLII exhibited weakened cellobiose hydrolytic activity, but produced some transglycosylation products, suggesting that the SNP in bgl2 strongly diminished cellobiase activity, but did not result in complete loss of function of BGLII. The analysis of the recombinant BGLII revealed that transglycosylation products might be oligosaccharides, composed probably of glucose linked β-1,4, β-1,3, or a mixture of both. PC-3-7 revertants of bgl2 exhibited reduced expression and inducibility of cellulase during growth on cellulose and cellobiose substrates. Furthermore, the effect of this bgl2 mutation was reproduced in the common strain QM9414 in which the transformants showed cellulase production comparable to that of PC-3-7. We conclude that BGLII plays an important role in cellulase induction in T. reesei and that the bgl2 mutation in PC-3-7 brought about enhanced cellulase expression on

  18. WNK1/HSN2 mutation in human peripheral neuropathy deregulates KCC2 expression and posterior lateral line development in zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Valérie Bercier

    Full Text Available Hereditary sensory and autonomic neuropathy type 2 (HSNAII is a rare pathology characterized by an early onset of severe sensory loss (all modalities in the distal limbs. It is due to autosomal recessive mutations confined to exon "HSN2" of the WNK1 (with-no-lysine protein kinase 1 serine-threonine kinase. While this kinase is well studied in the kidneys, little is known about its role in the nervous system. We hypothesized that the truncating mutations present in the neural-specific HSN2 exon lead to a loss-of-function of the WNK1 kinase, impairing development of the peripheral sensory system. To investigate the mechanisms by which the loss of WNK1/HSN2 isoform function causes HSANII, we used the embryonic zebrafish model and observed strong expression of WNK1/HSN2 in neuromasts of the peripheral lateral line (PLL system by immunohistochemistry. Knocking down wnk1/hsn2 in embryos using antisense morpholino oligonucleotides led to improper PLL development. We then investigated the reported interaction between the WNK1 kinase and neuronal potassium chloride cotransporter KCC2, as this transporter is a target of WNK1 phosphorylation. In situ hybridization revealed kcc2 expression in mature neuromasts of the PLL and semi-quantitative RT-PCR of wnk1/hsn2 knockdown embryos showed an increased expression of kcc2 mRNA. Furthermore, overexpression of human KCC2 mRNA in embryos replicated the wnk1/hsn2 knockdown phenotype. We validated these results by obtaining double knockdown embryos, both for wnk1/hsn2 and kcc2, which alleviated the PLL defects. Interestingly, overexpression of inactive mutant KCC2-C568A, which does not extrude ions, allowed a phenocopy of the PLL defects. These results suggest a pathway in which WNK1/HSN2 interacts with KCC2, producing a novel regulation of its transcription independent of KCC2's activation, where a loss-of-function mutation in WNK1 induces an overexpression of KCC2 and hinders proper peripheral sensory nerve

  19. Penetrance of eye defects in mice heterozygous for mutation of Gli3 is enhanced by heterozygous mutation of Pax6

    Directory of Open Access Journals (Sweden)

    Price David J

    2006-10-01

    Full Text Available Abstract Background Knowledge of the consequences of heterozygous mutations of developmentally important genes is important for understanding human genetic disorders. The Gli3 gene encodes a zinc finger transcription factor and homozygous loss-of-function mutations of Gli3 are lethal. Humans heterozygous for mutations in this gene suffer Greig cephalopolysyndactyly or Pallister-Hall syndromes, in which limb defects are prominent, and mice heterozygous for similar mutations have extra digits. Here we examined whether eye development, which is abnormal in mice lacking functional Gli3, is defective in Gli3+/- mice. Results We showed that Gli3 is expressed in the developing eye but that Gli3+/- mice have only very subtle eye defects. We then generated mice compound heterozygous for mutations in both Gli3 and Pax6, which encodes another developmentally important transcription factor known to be crucial for eye development. Pax6+/-; Gli3+/- eyes were compared to the eyes of wild-type, Pax6+/- or Gli3+/- siblings. They exhibited a range of abnormalities of the retina, iris, lens and cornea that was more extensive than in single Gli3+/- or Pax6+/- mutants or than would be predicted by addition of their phenotypes. Conclusion These findings indicate that heterozygous mutations of Gli3 can impact on eye development. The importance of a normal Gli3 gene dosage becomes greater in the absence of a normal Pax6 gene dosage, suggesting that the two genes co-operate during eye morphogenesis.

  20. Arabidopsis semidwarfs evolved from independent mutations in GA20ox1, ortholog to green revolution dwarf alleles in rice and barley.

    Science.gov (United States)

    Barboza, Luis; Effgen, Sigi; Alonso-Blanco, Carlos; Kooke, Rik; Keurentjes, Joost J B; Koornneef, Maarten; Alcázar, Rubén

    2013-09-24

    Understanding the genetic bases of natural variation for developmental and stress-related traits is a major goal of current plant biology. Variation in plant hormone levels and signaling might underlie such phenotypic variation occurring even within the same species. Here we report the genetic and molecular basis of semidwarf individuals found in natural Arabidopsis thaliana populations. Allelism tests demonstrate that independent loss-of-function mutations at GA locus 5 (GA5), which encodes gibberellin 20-oxidase 1 (GA20ox1) involved in the last steps of gibberellin biosynthesis, are found in different populations from southern, western, and northern Europe; central Asia; and Japan. Sequencing of GA5 identified 21 different loss-of-function alleles causing semidwarfness without any obvious general tradeoff affecting plant performance traits. GA5 shows signatures of purifying selection, whereas GA5 loss-of-function alleles can also exhibit patterns of positive selection in specific populations as shown by Fay and Wu's H statistics. These results suggest that antagonistic pleiotropy might underlie the occurrence of GA5 loss-of-function mutations in nature. Furthermore, because GA5 is the ortholog of rice SD1 and barley Sdw1/Denso green revolution genes, this study illustrates the occurrence of conserved adaptive evolution between wild A.thaliana and domesticated plants.

  1. Somatic Mutational Landscape of Splicing Factor Genes and Their Functional Consequences across 33 Cancer Types

    Directory of Open Access Journals (Sweden)

    Michael Seiler

    2018-04-01

    Full Text Available Summary: Hotspot mutations in splicing factor genes have been recently reported at high frequency in hematological malignancies, suggesting the importance of RNA splicing in cancer. We analyzed whole-exome sequencing data across 33 tumor types in The Cancer Genome Atlas (TCGA, and we identified 119 splicing factor genes with significant non-silent mutation patterns, including mutation over-representation, recurrent loss of function (tumor suppressor-like, or hotspot mutation profile (oncogene-like. Furthermore, RNA sequencing analysis revealed altered splicing events associated with selected splicing factor mutations. In addition, we were able to identify common gene pathway profiles associated with the presence of these mutations. Our analysis suggests that somatic alteration of genes involved in the RNA-splicing process is common in cancer and may represent an underappreciated hallmark of tumorigenesis. : Seiler et al. report that 119 splicing factor genes carry putative driver mutations over 33 tumor types in TCGA. The most common mutations appear to be mutually exclusive and are associated with lineage-independent altered splicing. Samples with these mutations show deregulation of cell-autonomous pathways and immune infiltration. Keywords: splicing, SF3B1, U2AF1, SRSF2, RBM10, FUBP1, cancer, mutation

  2. A novel lamin A/C mutation in a Dutch family with premature atherosclerosis.

    Science.gov (United States)

    Weterings, A A W; van Rijsingen, I A W; Plomp, A S; Zwinderman, A H; Lekanne Deprez, R H; Mannens, M M; van den Bergh Weerman, M A; van der Wal, A C; Pinto-Sietsma, S J

    2013-07-01

    We report a novel lamin A/C (LMNA) mutation, p.Glu223Lys, in a family with extensive atherosclerosis, diabetes mellitus and steatosis hepatis. Sequence analysis of LMNA (using Alamut version 2.2), co-segregation analysis, electron microscopy, extensive phenotypic evaluation of the mutation carriers and literature comparison were used to determine the loss of function of this mutation. The father of three siblings died at the age of 45 years. The three siblings and the brother and sister of the father were referred to the cardiovascular genetics department, because of the premature atherosclerosis and dysmorphic characteristics observed in the father at autopsy. The novel LMNA mutation, p.Glu223Lys, was identified in the proband and his two sons. Clinical evaluation revealed atherosclerosis, insulin resistance and hypertension in the proband and dyslipidemia and hepatic steatosis in all the patients with the mutation. Based on the facts that in silico analysis predicts a possibly pathogenic mutation, the mutation co-segregates with the disease, only fibroblasts from mutation carriers show nuclear blebbing and a similar phenotype was reported to be due to missense mutations in LMNA we conclude that we deal with a pathogenic mutation. We conclude that the phenotype is similar to Dunnigan-type familial partial lipodystrophy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. A Kir2.1 gain-of-function mutation underlies familial atrial fibrillation

    DEFF Research Database (Denmark)

    Xia, Min; Jin, Qingfeng; Bendahhou, Saïd

    2005-01-01

    that KCNJ2 was associated with familial AF. Thirty Chinese AF kindreds were evaluated for mutations in KCNJ2 gene. A valine-to-isoleucine mutation at position 93 (V93I) of Kir2.1 was found in all affected members in one kindred. This valine and its flanking sequence is highly conserved in Kir2.1 proteins...... among different species. Functional analysis of the V93I mutant demonstrated a gain-of-function consequence on the Kir2.1 current. This effect is opposed to the loss-of-function effect of previously reported mutations in Andersen's syndrome. Kir2.1 V93I mutation may play a role in initiating and...

  4. Alleged Detrimental Mutations in the SMPD1 Gene in Patients with Niemann-Pick Disease

    Directory of Open Access Journals (Sweden)

    Cosima Rhein

    2015-06-01

    Full Text Available Loss-of-function mutations in the sphingomyelin phosphodiesterase 1 (SMPD1 gene are associated with decreased catalytic activity of acid sphingomyelinase (ASM and are the cause of the autosomal recessive lysosomal storage disorder Niemann-Pick disease (NPD types A and B. Currently, >100 missense mutations in SMPD1 are listed in the Human Gene Mutation Database. However, not every sequence variation in SMPD1 is detrimental and gives rise to NPD. We have analysed several alleged SMPD1 missense mutations mentioned in a recent publication and found them to be common variants of SMPD1 that give rise to normal in vivo and in vitro ASM activity. (Comment on Manshadi et al. Int. J. Mol. Sci. 2015, 16, 6668–6676.

  5. Alzheimer's disease due to loss of function

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2016-01-01

    Alzheimer's Disease (AD) is a highly complex disease involving a broad range of clinical, cellular, and biochemical manifestations that are currently not understood in combination. This has led to many views of AD, e.g. the amyloid, tau, presenilin, oxidative stress, and metal hypotheses. The amy......Alzheimer's Disease (AD) is a highly complex disease involving a broad range of clinical, cellular, and biochemical manifestations that are currently not understood in combination. This has led to many views of AD, e.g. the amyloid, tau, presenilin, oxidative stress, and metal hypotheses...

  6. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  7. Mutations in the glutaminyl-tRNA synthetase gene cause early-onset epileptic encephalopathy.

    Science.gov (United States)

    Kodera, Hirofumi; Osaka, Hitoshi; Iai, Mizue; Aida, Noriko; Yamashita, Akio; Tsurusaki, Yoshinori; Nakashima, Mitsuko; Miyake, Noriko; Saitsu, Hirotomo; Matsumoto, Naomichi

    2015-02-01

    Aminoacylation is the process of attaching amino acids to their cognate tRNA, and thus is essential for the translation of mRNA into protein. This direct interaction of tRNA with amino acids is catalyzed by aminoacyl-tRNA synthetases. Using whole-exome sequencing, we identified compound heterozygous mutations [c.169T>C (p.Tyr57His) and c.1485dup (p.Lys496*)] in QARS, which encodes glutaminyl-tRNA synthetase, in two siblings with early-onset epileptic encephalopathy (EOEE). Recessive mutations in QARS, including the loss-of-function missense mutation p.Tyr57His, have been reported to cause intractable seizures with progressive microcephaly. The p.Lys496* mutation is novel and causes truncation of the QARS protein, leading to a deletion of part of the catalytic domain and the entire anticodon-binding domain. Transient expression of the p.Lys496* mutant in neuroblastoma 2A cells revealed diminished and aberrantly aggregated expression, indicating the loss-of-function nature of this mutant. Together with the previous report, our data suggest that abnormal aminoacylation is one of the underlying pathologies of EOEE.

  8. R31C GNRH1 Mutation and Congenital Hypogonadotropic Hypogonadism

    Science.gov (United States)

    Maione, Luigi; Albarel, Frederique; Bouchard, Philippe; Gallant, Megan; Flanagan, Colleen A.; Bobe, Regis; Cohen-Tannoudji, Joelle; Pivonello, Rosario; Colao, Annamaria; Brue, Thierry; Millar, Robert P.; Lombes, Marc; Young, Jacques; Guiochon-Mantel, Anne; Bouligand, Jerome

    2013-01-01

    Normosmic congenital hypogonadotropic hypogonadism (nCHH) is a rare reproductive disease leading to lack of puberty and infertility. Loss-of-function mutations of GNRH1 gene are a very rare cause of autosomal recessive nCHH. R31C GNRH1 is the only missense mutation that affects the conserved GnRH decapeptide sequence. This mutation was identified in a CpG islet in nine nCHH subjects from four unrelated families, giving evidence for a putative “hot spot”. Interestingly, all the nCHH patients carry this mutation in heterozygosis that strikingly contrasts with the recessive inheritance associated with frame shift and non-sense mutations. Therefore, after exclusion of a second genetic event, a comprehensive functional characterization of the mutant R31C GnRH was undertaken. Using different cellular models, we clearly demonstrate a dramatic reduction of the mutant decapeptide capacity to bind GnRH-receptor, to activate MAPK pathway and to trigger inositol phosphate accumulation and intracellular calcium mobilization. In addition it is less able than wild type to induce lh-beta transcription and LH secretion in gonadotrope cells. Finally, the absence of a negative dominance in vitro offers a unique opportunity to discuss the complex in vivo patho-physiology of this form of nCHH. PMID:23936060

  9. R31C GNRH1 mutation and congenital hypogonadotropic hypogonadism.

    Directory of Open Access Journals (Sweden)

    Luigi Maione

    Full Text Available Normosmic congenital hypogonadotropic hypogonadism (nCHH is a rare reproductive disease leading to lack of puberty and infertility. Loss-of-function mutations of GNRH1 gene are a very rare cause of autosomal recessive nCHH. R31C GNRH1 is the only missense mutation that affects the conserved GnRH decapeptide sequence. This mutation was identified in a CpG islet in nine nCHH subjects from four unrelated families, giving evidence for a putative "hot spot". Interestingly, all the nCHH patients carry this mutation in heterozygosis that strikingly contrasts with the recessive inheritance associated with frame shift and non-sense mutations. Therefore, after exclusion of a second genetic event, a comprehensive functional characterization of the mutant R31C GnRH was undertaken. Using different cellular models, we clearly demonstrate a dramatic reduction of the mutant decapeptide capacity to bind GnRH-receptor, to activate MAPK pathway and to trigger inositol phosphate accumulation and intracellular calcium mobilization. In addition it is less able than wild type to induce lh-beta transcription and LH secretion in gonadotrope cells. Finally, the absence of a negative dominance in vitro offers a unique opportunity to discuss the complex in vivo patho-physiology of this form of nCHH.

  10. The mutational spectrum of FOXA2 in endometrioid endometrial cancer points to a tumor suppressor role.

    Science.gov (United States)

    Smith, B; Neff, R; Cohn, D E; Backes, F J; Suarez, A A; Mutch, D G; Rush, C M; Walker, C J; Goodfellow, P J

    2016-11-01

    Forkhead box protein A2 (FOXA2) plays an important in development, cellular metabolism and tumorigenesis. The Cancer Genome Atlas (TCGA) identified a modest frequency of FOXA2 mutations in endometrioid endometrial cancers (EEC). The current study sought to determine the relationship between FOXA2 mutation and clinicopathologic features in EEC and FOXA2 expression. Polymerase chain reaction (PCR) amplification and sequencing were used to identify mutations in 542 EEC. Western blot, quantitative reverse transcriptase PCR (qRT-PCR) and immunohistochemistry (IHC) were used to assess expression. Methylation analysis was performed using combined bisulfite restriction analysis (COBRA) and sequencing. Chi-squared, Fisher's exact, Student's t- and log-rank tests were performed. Fifty-one mutations were identified in 49 tumors (9.4% mutation rate). The majority of mutations were novel, loss of function (LOF) (78.4%) mutations, and most disrupted the DNA-binding domain (58.8%). Six recurrent mutations were identified. Only two tumors had two mutations and there was no evidence for FOXA2 allelic loss. Mutation status was associated with tumor grade and not associated with survival outcomes. Methylation of the FOXA2 promoter region was highly variable. Most tumors expressed FOXA2 at both the mRNA and protein level. In those tumors with mutations, the majority of cases expressed both alleles. FOXA2 is frequently mutated in EEC. The pattern of FOXA2 mutations and expression in tumors suggests complex regulation and a haploinsufficient or dominant-negative tumor suppressor function. In vitro studies may shed light on how mutations in FOXA2 affect FOXA2 pioneer and/or transcription factor functions in EEC. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Early-onset encephalopathy with epilepsy associated with a novel splice site mutation in SMC1A.

    Science.gov (United States)

    Lebrun, Nicolas; Lebon, Sébastien; Jeannet, Pierre-Yves; Jacquemont, Sébastien; Billuart, Pierre; Bienvenu, Thierry

    2015-12-01

    We report on the clinical and molecular characterization of a female patient with early-onset epileptic encephalopathy, who was found to carry a de novo novel splice site mutation in SMC1A. This girl shared some morphologic and anthropometric traits described in patients with clinical diagnosis of Cornelia de Lange syndrome and with SMC1A mutation but also has severe encephalopathy with early-onset epilepsy. In addition, she had midline hand stereotypies and scoliosis leading to the misdiagnosis of a Rett overlap syndrome. Molecular studies found a novel de novo splice site mutation (c.1911 + 1G > T) in SMC1A. This novel splice mutation was associated with an aberrantly processed mRNA that included intron 11 of the gene. Moreover, quantitative approach by RT-PCR showed a severe reduction of the SMC1A transcript suggesting that this aberrant transcript may be unstable and degraded. Taken together, our data suggest that the phenotype may be due to a loss-of-function of SMC1A in this patient. Our findings suggest that loss-of-function mutations of SMC1A may be associated with early-onset encephalopathy with epilepsy. © 2015 Wiley Periodicals, Inc.

  12. Petroleum pollution and mutation in mangroves

    International Nuclear Information System (INIS)

    Klekowski, E.J. Jr.; Corredor, J.E.; Morell, J.M.; Del Castillo, C.A.

    1994-01-01

    Chlorophyll-deficiency has often been used as a sensitive genetic end-point in plant mutation research. The frequency of trees heterozygous for nuclear chlorophyll-deficient mutations was determined for mangrove populations growing along the southwest coast of Puerto Rico. The frequency of heterozygotes was strongly correlated with the concentration of polycyclic aromatic hydrocarbons in the underlying sediment and with both acute and chronic petroleum pollution. Although epidemiological studies can seldom prove causation, a strong correlation is certainly compatible with a cause-effect relationship. Our results suggest that the biota of oil-polluted habitats may be experiencing increased mutation. (Author)

  13. A Novel ABCA12 Mutation in Two Families with Congenital Ichthyosis

    Directory of Open Access Journals (Sweden)

    D. M. Walsh

    2012-01-01

    Full Text Available Autosomal recessive congenital ichthyosis (ARCI is a rare genetically heterogeneous disorder characterized by hyperkeratosis in addition to dry, scaly skin. There are six genes currently known to be associated with the disease. Exome sequencing data for two affected individuals with ichthyosis from two apparently unrelated consanguineous Pakistani families was analysed. Potential candidate mutations were analysed in additional family members to determine if the putative mutation segregated with disease status. A novel mutation (c.G4676T, p.Gly1559Val in ABCA12 occurred at a highly conserved residue, segregated with disease status in both families, and was not detected in 143 control chromosomes. Genotyping with microsatellite markers demonstrated a partial common haplotype in the two families, and a common founder mutation could not be excluded. Comparison to previously reported cases was consistent with the hypothesis that severe loss of function ABCA12 mutations are associated with Harlequin Ichthyosis and missense mutations are preferentially associated with milder phenotypes. In addition to identifying a possible founder mutation, this paper illustrates how advances in genome sequencing technologies could be utilised to rapidly elucidate the molecular basis of inherited skin diseases which can be caused by mutations in multiple disease genes.

  14. Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster.

    Science.gov (United States)

    Kahsai, Lily; Cook, Kevin R

    2018-01-04

    Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes. Copyright © 2018 Kahsai,Cook.

  15. Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Lily Kahsai

    2018-01-01

    Full Text Available Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes.

  16. De Novo Mutations in EBF3 Cause a Neurodevelopmental Syndrome.

    Science.gov (United States)

    Sleven, Hannah; Welsh, Seth J; Yu, Jing; Churchill, Mair E A; Wright, Caroline F; Henderson, Alex; Horvath, Rita; Rankin, Julia; Vogt, Julie; Magee, Alex; McConnell, Vivienne; Green, Andrew; King, Mary D; Cox, Helen; Armstrong, Linlea; Lehman, Anna; Nelson, Tanya N; Williams, Jonathan; Clouston, Penny; Hagman, James; Németh, Andrea H

    2017-01-05

    Early B cell factor 3 (EBF3) is an atypical transcription factor that is thought to influence the laminar formation of the cerebral cortex. Here, we report that de novo mutations in EBF3 cause a complex neurodevelopmental syndrome. The mutations were identified in two large-scale sequencing projects: the UK Deciphering Developmental Disorders (DDD) study and the Canadian Clinical Assessment of the Utility of Sequencing and Evaluation as a Service (CAUSES) study. The core phenotype includes moderate to severe intellectual disability, and many individuals exhibit cerebellar ataxia, subtle facial dysmorphism, strabismus, and vesicoureteric reflux, suggesting that EBF3 has a widespread developmental role. Pathogenic de novo variants identified in EBF3 include multiple loss-of-function and missense mutations. Structural modeling suggested that the missense mutations affect DNA binding. Functional analysis of mutant proteins with missense substitutions revealed reduced transcriptional activities and abilities to form heterodimers with wild-type EBF3. We conclude that EBF3, a transcription factor previously unknown to be associated with human disease, is important for brain and other organ development and warrants further investigation. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  17. Spliceosome mutations exhibit specific associations with epigenetic modifiers and proto-oncogenes mutated in myelodysplastic syndrome.

    Science.gov (United States)

    Mian, Syed A; Smith, Alexander E; Kulasekararaj, Austin G; Kizilors, Aytug; Mohamedali, Azim M; Lea, Nicholas C; Mitsopoulos, Konstantinos; Ford, Kevin; Nasser, Erick; Seidl, Thomas; Mufti, Ghulam J

    2013-07-01

    The recent identification of acquired mutations in key components of the spliceosome machinery strongly implicates abnormalities of mRNA splicing in the pathogenesis of myelodysplastic syndromes. However, questions remain as to how these aberrations functionally combine with the growing list of mutations in genes involved in epigenetic modification and cell signaling/transcription regulation identified in these diseases. In this study, amplicon sequencing was used to perform a mutation screen in 154 myelodysplastic syndrome patients using a 22-gene panel, including commonly mutated spliceosome components (SF3B1, SRSF2, U2AF1, ZRSR2), and a further 18 genes known to be mutated in myeloid cancers. Sequencing of the 22-gene panel revealed that 76% (n=117) of the patients had mutations in at least one of the genes, with 38% (n=59) having splicing gene mutations and 49% (n=75) patients harboring more than one gene mutation. Interestingly, single and specific epigenetic modifier mutations tended to coexist with SF3B1 and SRSF2 mutations (P<0.03). Furthermore, mutations in SF3B1 and SRSF2 were mutually exclusive to TP53 mutations both at diagnosis and at the time of disease transformation. Moreover, mutations in FLT3, NRAS, RUNX1, CCBL and C-KIT were more likely to co-occur with splicing factor mutations generally (P<0.02), and SRSF2 mutants in particular (P<0.003) and were significantly associated with disease transformation (P<0.02). SF3B1 and TP53 mutations had varying impacts on overall survival with hazard ratios of 0.2 (P<0.03, 95% CI, 0.1-0.8) and 2.1 (P<0.04, 95% CI, 1.1-4.4), respectively. Moreover, patients with splicing factor mutations alone had a better overall survival than those with epigenetic modifier mutations, or cell signaling/transcription regulator mutations with and without coexisting mutations of splicing factor genes, with worsening prognosis (P<0.001). These findings suggest that splicing factor mutations are maintained throughout disease

  18. Precise estimates of mutation rate and spectrum in yeast

    Science.gov (United States)

    Zhu, Yuan O.; Siegal, Mark L.; Hall, David W.; Petrov, Dmitri A.

    2014-01-01

    Mutation is the ultimate source of genetic variation. The most direct and unbiased method of studying spontaneous mutations is via mutation accumulation (MA) lines. Until recently, MA experiments were limited by the cost of sequencing and thus provided us with small numbers of mutational events and therefore imprecise estimates of rates and patterns of mutation. We used whole-genome sequencing to identify nearly 1,000 spontaneous mutation events accumulated over ∼311,000 generations in 145 diploid MA lines of the budding yeast Saccharomyces cerevisiae. MA experiments are usually assumed to have negligible levels of selection, but even mild selection will remove strongly deleterious events. We take advantage of such patterns of selection and show that mutation classes such as indels and aneuploidies (especially monosomies) are proportionately much more likely to contribute mutations of large effect. We also provide conservative estimates of indel, aneuploidy, environment-dependent dominant lethal, and recessive lethal mutation rates. To our knowledge, for the first time in yeast MA data, we identified a sufficiently large number of single-nucleotide mutations to measure context-dependent mutation rates and were able to (i) confirm strong AT bias of mutation in yeast driven by high rate of mutations from C/G to T/A and (ii) detect a higher rate of mutation at C/G nucleotides in two specific contexts consistent with cytosine methylation in S. cerevisiae. PMID:24847077

  19. A null mutation inSERPINE1protects against biological aging in humans.

    Science.gov (United States)

    Khan, Sadiya S; Shah, Sanjiv J; Klyachko, Ekaterina; Baldridge, Abigail S; Eren, Mesut; Place, Aaron T; Aviv, Abraham; Puterman, Eli; Lloyd-Jones, Donald M; Heiman, Meadow; Miyata, Toshio; Gupta, Sweta; Shapiro, Amy D; Vaughan, Douglas E

    2017-11-01

    Plasminogen activator inhibitor-1 (PAI-1) has been shown to be a key component of the senescence-related secretome and a direct mediator of cellular senescence. In murine models of accelerated aging, genetic deficiency and targeted inhibition of PAI-1 protect against aging-like pathology and prolong life span. However, the role of PAI-1 in human longevity remains unclear. We hypothesized that a rare loss-of-function mutation in SERPINE1 (c.699_700dupTA), which encodes PAI-1, could play a role in longevity and metabolism in humans. We studied 177 members of the Berne Amish community, which included 43 carriers of the null SERPINE1 mutation. Heterozygosity was associated with significantly longer leukocyte telomere length, lower fasting insulin levels, and lower prevalence of diabetes mellitus. In the extended Amish kindred, carriers of the null SERPINE1 allele had a longer life span. Our study indicates a causal effect of PAI-1 on human longevity, which may be mediated by alterations in metabolism. Our findings demonstrate the utility of studying loss-of-function mutations in populations with geographic and genetic isolation and shed light on a novel therapeutic target for aging.

  20. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  1. Novel loss-of-function PCSK9 variant is associated with low plasma LDL cholesterol in a French-Canadian family and with impaired processing and secretion in cell culture.

    Science.gov (United States)

    Mayne, Janice; Dewpura, Thilina; Raymond, Angela; Bernier, Lise; Cousins, Marion; Ooi, Teik Chye; Davignon, Jean; Seidah, Nabil G; Mbikay, Majambu; Chrétien, Michel

    2011-10-01

    PCSK9 (proprotein convertase subtilisin/kexin type 9) is a polymorphic gene whose protein product regulates plasma LDL cholesterol (LDLC) concentrations by shuttling liver LDL receptors (LDLRs) for degradation. PCSK9 variants that cause a gain or loss of PCSK9 function are associated with hyper- or hypocholesterolemia, which increases or reduces the risk of cardiovascular disease, respectively. We studied the clinical and molecular characteristics of a novel PCSK9 loss-of-function sequence variant in a white French-Canadian family. In vivo plasma and ex vivo secreted PCSK9 concentrations were measured with a commercial ELISA. We sequenced the PCSK9 exons for 15 members of a family, the proband of which exhibited very low plasma PCSK9 and LDLC concentrations. We then conducted a structure/function analysis of the novel PCSK9 variant in cell culture to identify its phenotypic basis. We identified a PCSK9 sequence variant in the French-Canadian family that produced the PCSK9 Q152H substitution. Family members carrying this variant had mean decreases in circulating PCSK9 and LDLC concentrations of 79% and 48%, respectively, compared with unrelated noncarriers (n=210). In cell culture, the proPCSK9-Q152H variant did not undergo efficient autocatalytic cleavage and was not secreted. Cells transiently transfected with PCSK9-Q152H cDNA had LDLR concentrations that were significantly higher than those of cells overproducing wild-type PCSK9 (PCSK9-WT). Cotransfection of PCSK9-Q152H and PCSK9-WT cDNAs produced a 78% decrease in the secreted PCSK9-WT protein compared with control cells. Collectively, our results demonstrate that the PCSK9-Q152H variant markedly lowers plasma PCSK9 and LDLC concentrations in heterozygous carriers via decreased autocatalytic processing and secretion, and hence, inactivity on the LDLR.

  2. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  3. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  4. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  5. Kallmann syndrome: mutations in the genes encoding prokineticin-2 and prokineticin receptor-2.

    Directory of Open Access Journals (Sweden)

    Catherine Dodé

    2006-10-01

    Full Text Available Kallmann syndrome combines anosmia, related to defective olfactory bulb morphogenesis, and hypogonadism due to gonadotropin-releasing hormone deficiency. Loss-of-function mutations in KAL1 and FGFR1 underlie the X chromosome-linked form and an autosomal dominant form of the disease, respectively. Mutations in these genes, however, only account for approximately 20% of all Kallmann syndrome cases. In a cohort of 192 patients we took a candidate gene strategy and identified ten and four different point mutations in the genes encoding the G protein-coupled prokineticin receptor-2 (PROKR2 and one of its ligands, prokineticin-2 (PROK2, respectively. The mutations in PROK2 were detected in the heterozygous state, whereas PROKR2 mutations were found in the heterozygous, homozygous, or compound heterozygous state. In addition, one of the patients heterozygous for a PROKR2 mutation was also carrying a missense mutation in KAL1, thus indicating a possible digenic inheritance of the disease in this individual. These findings reveal that insufficient prokineticin-signaling through PROKR2 leads to abnormal development of the olfactory system and reproductive axis in man. They also shed new light on the complex genetic transmission of Kallmann syndrome.

  6. Comprehensive analysis of cancer-associated somatic mutations in class I HLA genes

    Science.gov (United States)

    Shukla, Sachet A.; Rooney, Michael S.; Rajasagi, Mohini; Tiao, Grace; Dixon, Philip M.; Lawrence, Michael S.; Stevens, Jonathan; Lane, William J.; Dellagatta, Jamie L.; Steelman, Scott; Sougnez, Carrie; Cibulskis, Kristian; Kiezun, Adam; Brusic, Vladimir; Wu, Catherine J.; Getz, Gad

    2015-01-01

    Detection of somatic mutations in HLA genes using whole-exome sequencing (WES) is hampered by the high polymorphism of the HLA loci, which prevents alignment of sequencing reads to the human reference genome. We describe a computational pipeline that enables accurate inference of germline alleles of class I HLA-A, -B and -C genes and subsequent detection of mutations in these genes using the inferred alleles as a reference. Analysis of WES data from 7,930 pairs of tumor and healthy tissue from the same patient revealed 298 non-silent HLA mutations in tumors from 266 patients. These 298 mutations are enriched for likely functional mutations, including putative loss-of-function events. Recurrence of mutations suggested that these ‘hotspot’ sites were positively selected. Cancers with recurrent somatic HLA mutations were associated with upregulation of signatures of cytolytic activity characteristic of tumor infiltration by effector lymphocytes, supporting immune evasion by altered HLA function as a contributory mechanism in cancer. PMID:26372948

  7. A functional alternative splicing mutation in AIRE gene causes autoimmune polyendocrine syndrome type 1.

    Directory of Open Access Journals (Sweden)

    Junyu Zhang

    Full Text Available Autoimmune polyendocrine syndrome type 1 (APS-1 is a rare autosomal recessive disease defined by the presence of two of the three conditions: mucocutaneous candidiasis, hypoparathyroidism, and Addison's disease. Loss-of-function mutations of the autoimmune regulator (AIRE gene have been linked to APS-1. Here we report mutational analysis and functional characterization of an AIRE mutation in a consanguineous Chinese family with APS-1. All exons of the AIRE gene and adjacent exon-intron sequences were amplified by PCR and subsequently sequenced. We identified a homozygous missense AIRE mutation c.463G>A (p.Gly155Ser in two siblings with different clinical features of APS-1. In silico splice-site prediction and minigene analysis were carried out to study the potential pathological consequence. Minigene splicing analysis and subsequent cDNA sequencing revealed that the AIRE mutation potentially compromised the recognition of the splice donor of intron 3, causing alternative pre-mRNA splicing by intron 3 retention. Furthermore, the aberrant AIRE transcript was identified in a heterozygous carrier of the c.463G>A mutation. The aberrant intron 3-retaining transcript generated a truncated protein (p.G155fsX203 containing the first 154 AIRE amino acids and followed by 48 aberrant amino acids. Therefore, our study represents the first functional characterization of the alternatively spliced AIRE mutation that may explain the pathogenetic role in APS-1.

  8. Eating behaviour in obese patients with melanocortin-4 receptor mutations: a literature review.

    Science.gov (United States)

    Valette, M; Bellisle, F; Carette, C; Poitou, C; Dubern, B; Paradis, G; Hercberg, S; Muzard, L; Clément, K; Czernichow, S

    2013-08-01

    Melanocortin-4 receptor (MC4R) mutations are the most common known cause of monogenic obesity and an important contributor to polygenic obesity. MC4R mutations with partial or total loss of function, as well as the variant rs17782313 mapped near MC4R, are positively associated with obesity. MC4R is involved in the leptin-melanocortin signalling system, located in hypothalamic nuclei, that controls food intake via both anorexigenic or orexigenic signals. Impairment in this receptor might affect eating behaviours. Thus, in the case of MC4R mutation carriers, obesity could be related, at least partly, to inadequate control over eating behaviours. Many published studies address eating behaviours in MC4R mutation carriers. Most studies focus on binge eating disorder, whereas others examine various aspects of intake and motivation. Up to now, no evaluation of this literature has been performed. In this review, we examine the available literature on eating behaviours in carriers of MC4R mutations and variant rs17782313 near MC4R gene. We address binge eating disorder, bulimia nervosa, mealtime hyperphagia, snacking, psychological factors, satiety responsiveness and intake of energy and macro/micronutrient. In a small number of studies, MC4R mutations seem to impair eating behaviours or motivation, but no clear causal effects can be found in the balance of the evidence presented. Improvements in methodologies will be necessary to clarify the behavioural effects of MC4R mutations.

  9. Compound heterozygous mutations in UBA5 causing early-onset epileptic encephalopathy in two sisters.

    Science.gov (United States)

    Arnadottir, Gudny A; Jensson, Brynjar O; Marelsson, Sigurdur E; Sulem, Gerald; Oddsson, Asmundur; Kristjansson, Ragnar P; Benonisdottir, Stefania; Gudjonsson, Sigurjon A; Masson, Gisli; Thorisson, Gudmundur A; Saemundsdottir, Jona; Magnusson, Olafur Th; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Sigurdsson, Asgeir; Gudbjartsson, Daniel F; Thorsteinsdottir, Unnur; Arngrimsson, Reynir; Sulem, Patrick; Stefansson, Kari

    2017-10-02

    Epileptic encephalopathies are a group of childhood epilepsies that display high phenotypic and genetic heterogeneity. The recent, extensive use of next-generation sequencing has identified a large number of genes in epileptic encephalopathies, including UBA5 in which biallelic mutations were first described as pathogenic in 2016 (Colin E et al., Am J Hum Genet 99(3):695-703, 2016. Muona M et al., Am J Hum Genet 99(3):683-694, 2016). UBA5 encodes an activating enzyme for a post-translational modification mechanism known as ufmylation, and is the first gene from the ufmylation pathway that is linked to disease. We sequenced the genomes of two sisters with early-onset epileptic encephalopathy along with their unaffected parents in an attempt to find a genetic cause for their condition. The sisters, born in 2004 and 2006, presented with infantile spasms at six months of age, which later progressed to recurrent, treatment-resistant seizures. We detected a compound heterozygous genotype in UBA5 in the sisters, a genotype not seen elsewhere in an Icelandic reference set of 30,067 individuals nor in public databases. One of the mutations, c.684G > A, is a paternally inherited exonic splicing mutation, occuring at the last nucleotide of exon 7 of UBA5. The mutation is predicted to disrupt the splice site, resulting in loss-of-function of one allele of UBA5. The second mutation is a maternally inherited missense mutation, p.Ala371Thr, previously reported as pathogenic when in compound heterozygosity with a loss-of-function mutation in UBA5 and is believed to produce a hypomorphic allele. Supportive of this, we have identified three adult Icelanders homozygous for the p.Ala371Thr mutation who show no signs of neurological disease. We describe compound heterozygous mutations in the UBA5 gene in two sisters with early-onset epileptic encephalopathy. To our knowledge, this is the first description of mutations in UBA5 since the initial discovery that pathogenic biallelic

  10. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  11. Interaction between GPR120 p.R270H loss-of-function variant and dietary fat intake on incident type 2 diabetes risk in the D.E.S.I.R. study.

    Science.gov (United States)

    Lamri, A; Bonnefond, A; Meyre, D; Balkau, B; Roussel, R; Marre, M; Froguel, P; Fumeron, F

    2016-10-01

    GPR120 (encoded by FFAR4) is a lipid sensor that plays an important role in the control of energy balance. GPR120 is activated by long chain fatty acids (FAs) including omega-3 FAs. In humans, the loss of function p.R270H variant of the gene FFAR4 has been associated with a lower protein activity, an increased risk of obesity and higher fasting plasma glucose levels. The aim of this study was to investigate whether p.R270H interacts with dietary fat intake to modulate the risk of type 2 diabetes (T2D, 198 incident; 368 prevalent cases) and overweight (787 incident and 2891 prevalent cases) in the prospective D.E.S.I.R. study (n = 5,212, 9 years follow-up). The association of p.R270H with dietary fat and total calories was assessed by linear mixed models. The interaction between p.R270H and dietary fat on T2D and overweight was assessed by logistic regression analysis. The p.R270H variant had a minor allele frequency of 1.45% and was not significantly associated with total calories intake, fat intake or the total calories derived from fat (%). However, there was a significant interaction between p.R270H and dietary fat modulating the incidence of T2D (Pinteraction = 0.02) where the H-carriers had a higher risk of T2D than RR homozygotes in the low fat intake category only. The interaction between p.R270H and fat intake modulating the incidence and prevalence of overweight was not significant. The p.R270H variant of GPR120 modulates the risk of T2D in interaction with dietary fat intake in the D.E.S.I.R. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  12. Suppression of severe achondroplasia with developmental delay and acanthosis nigricans by the p.Thr651Pro mutation.

    Science.gov (United States)

    Manickam, Kandamurugu; Donoghue, Daniel J; Meyer, April N; Snyder, Pamela J; Prior, Thomas W

    2014-01-01

    Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN) is an extremely rare severe skeletal dysplasia characterized by significant developmental delay, brain structural abnormalities, hearing loss, and acanthosis nigricans. The disorder is the result of a single missense mutation at codon 650 (p.Lys650Met) in the fibroblast growth factor receptor 3 gene (FGFR3). We describe a child who initially presented with a mild achondroplasia or hypochondroplasia like phenotype. Molecular analysis of the FGFR3 gene showed the common SADDAN mutation and a second novel mutation at codon 651 (p.Thr651Pro). Both mutations were shown to occur on the same allele (cis) and de novo. Transient transfection studies with FGFR3 double mutant constructs show that the p.Thr651Pro mutation causes a dramatic decrease in constitutive receptor kinase activity than that observed by the p.Lys650Met mutation. Our data suggest that the molecular effect by the p.Thr651Pro is to elicit a conformational change that decreases the FGFR3 tyrosine kinase activity, which is constitutively activated by the SADDAN mutation. Due to the inheritance of both a gain-of-function and a loss-of-function mutation, we conclude that a reduction of constitutive activation caused the milder skeletal phenotype. Although the occurrence of double mutations are expected to be rare, the presence of other FGFR3 modifiers may be responsible for some of the clinically discrepant skeletal dysplasia cases. © 2013 Wiley Periodicals, Inc.

  13. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  14. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  15. Type B mandibuloacral dysplasia with congenital myopathy due to homozygous ZMPSTE24 missense mutation.

    Science.gov (United States)

    Ben Yaou, Rabah; Navarro, Claire; Quijano-Roy, Susana; Bertrand, Anne T; Massart, Catherine; De Sandre-Giovannoli, Annachiara; Cadiñanos, Juan; Mamchaoui, Kamel; Butler-Browne, Gillian; Estournet, Brigitte; Richard, Pascale; Barois, Annie; Lévy, Nicolas; Bonne, Gisèle

    2011-06-01

    Mutation in ZMPSTE24 gene, encoding a major metalloprotease, leads to defective prelamin A processing and causes type B mandibuloacral dysplasia, as well as the lethal neonatal restrictive dermopathy syndrome. Phenotype severity is correlated with the residual enzyme activity of ZMPSTE24 and accumulation of prelamin A. We had previously demonstrated that a complete loss of function in ZMPSTE24 was lethal in the neonatal period, whereas compound heterozygous mutations including one PTC and one missense mutation were associated with type B mandibuloacral dysplasia. In this study, we report a 30-year longitudinal clinical survey of a patient harboring a novel severe and complex phenotype, combining an early-onset progeroid syndrome and a congenital myopathy with fiber-type disproportion. A unique homozygous missense ZMPSTE24 mutation (c.281T>C, p.Leu94Pro) was identified and predicted to produce two possible ZMPSTE24 conformations, leading to a partial loss of function. Western blot analysis revealed a major reduction of ZMPSTE24, together with the presence of unprocessed prelamin A and decreased levels of lamin A, in the patient's primary skin fibroblasts. These cells exhibited significant reductions in lifespan associated with major abnormalities of the nuclear shape and structure. This is the first report of MAD presenting with confirmed myopathic abnormalities associated with ZMPSTE24 defects, extending the clinical spectrum of ZMPSTE24 gene mutations. Moreover, our results suggest that defective prelamin A processing affects muscle regeneration and development, thus providing new insights into the disease mechanism of prelamin A-defective associated syndromes in general.

  16. Multiple mutations and mutation combinations in the sodium channel of permethrin resistant mosquitoes, Culex quinquefasciatus

    Science.gov (United States)

    Li, Ting; Zhang, Lee; Reid, William R.; Xu, Qiang; Dong, Ke; Liu, Nannan

    2012-10-01

    A previous study identified 3 nonsynonymous and 6 synonymous mutations in the entire mosquito sodium channel of Culex quinquefasciatus, the prevalence of which were strongly correlated with levels of resistance and increased dramatically following insecticide selection. However, it is unclear whether this is unique to this specific resistant population or is a common mechanism in field mosquito populations in response to insecticide pressure. The current study therefore further characterized these mutations and their combinations in other field and permethrin selected Culex mosquitoes, finding that the co-existence of all 9 mutations was indeed correlated with the high levels of permethrin resistance in mosquitoes. Comparison of mutation combinations revealed several common mutation combinations presented across different field and permethrin selected populations in response to high levels of insecticide resistance, demonstrating that the co-existence of multiple mutations is a common event in response to insecticide resistance across different Cx. quinquefasciatus mosquito populations.

  17. Mutations in LRRC50 predispose zebrafish and humans to seminomas.

    Directory of Open Access Journals (Sweden)

    Sander G Basten

    2013-04-01

    Full Text Available Seminoma is a subclass of human testicular germ cell tumors (TGCT, the most frequently observed cancer in young men with a rising incidence. Here we describe the identification of a novel gene predisposing specifically to seminoma formation in a vertebrate model organism. Zebrafish carrying a heterozygous nonsense mutation in Leucine-Rich Repeat Containing protein 50 (lrrc50 also called dnaaf1, associated previously with ciliary function, are found to be highly susceptible to the formation of seminomas. Genotyping of these zebrafish tumors shows loss of heterozygosity (LOH of the wild-type lrrc50 allele in 44.4% of tumor samples, correlating with tumor progression. In humans we identified heterozygous germline LRRC50 mutations in two different pedigrees with a family history of seminomas, resulting in a nonsense Arg488* change and a missense Thr590Met change, which show reduced expression of the wild-type allele in seminomas. Zebrafish in vivo complementation studies indicate the Thr590Met to be a loss-of-function mutation. Moreover, we show that a pathogenic Gln307Glu change is significantly enriched in individuals with seminoma tumors (13% of our cohort. Together, our study introduces an animal model for seminoma and suggests LRRC50 to be a novel tumor suppressor implicated in human seminoma pathogenesis.

  18. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  19. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  20. Deletions and de novo mutations of SOX11 are associated with a neurodevelopmental disorder with features of Coffin–Siris syndrome

    Science.gov (United States)

    Hempel, Annmarie; Pagnamenta, Alistair T; Blyth, Moira; Mansour, Sahar; McConnell, Vivienne; Kou, Ikuyo; Ikegawa, Shiro; Tsurusaki, Yoshinori; Matsumoto, Naomichi; Lo-Castro, Adriana; Plessis, Ghislaine; Albrecht, Beate; Battaglia, Agatino; Taylor, Jenny C; Howard, Malcolm F; Keays, David; Sohal, Aman Singh; Kühl, Susanne J; Kini, Usha; McNeill, Alisdair

    2016-01-01

    Background SOX11 is a transcription factor proposed to play a role in brain development. The relevance of SOX11 to human developmental disorders was suggested by a recent report of SOX11 mutations in two patients with Coffin–Siris syndrome. Here we further investigate the role of SOX11 variants in neurodevelopmental disorders. Methods We used array based comparative genomic hybridisation and trio exome sequencing to identify children with intellectual disability who have deletions or de novo point mutations disrupting SOX11. The pathogenicity of the SOX11 mutations was assessed using an in vitro gene expression reporter system. Loss-of-function experiments were performed in xenopus by knockdown of Sox11 expression. Results We identified seven individuals with chromosome 2p25 deletions involving SOX11. Trio exome sequencing identified three de novo SOX11 variants, two missense (p.K50N; p.P120H) and one nonsense (p.C29*). The biological consequences of the missense mutations were assessed using an in vitro gene expression system. These individuals had microcephaly, developmental delay and shared dysmorphic features compatible with mild Coffin–Siris syndrome. To further investigate the function of SOX11, we knocked down the orthologous gene in xenopus. Morphants had significant reduction in head size compared with controls. This suggests that SOX11 loss of function can be associated with microcephaly. Conclusions We thus propose that SOX11 deletion or mutation can present with a Coffin–Siris phenotype. PMID:26543203

  1. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  2. A de novo nonsense PDGFB mutation causing idiopathic basal ganglia calcification with laryngeal dystonia.

    Science.gov (United States)

    Nicolas, Gaël; Jacquin, Agnès; Thauvin-Robinet, Christel; Rovelet-Lecrux, Anne; Rouaud, Olivier; Pottier, Cyril; Aubriot-Lorton, Marie-Hélène; Rousseau, Stéphane; Wallon, David; Duvillard, Christian; Béjot, Yannick; Frébourg, Thierry; Giroud, Maurice; Campion, Dominique; Hannequin, Didier

    2014-10-01

    Idiopathic basal ganglia calcification (IBGC) is characterized by brain calcification and a wide variety of neurologic and psychiatric symptoms. In families with autosomal dominant inheritance, three causative genes have been identified: SLC20A2, PDGFRB, and, very recently, PDGFB. Whereas in clinical practice sporadic presentation of IBGC is frequent, well-documented reports of true sporadic occurrence are rare. We report the case of a 20-year-old woman who presented laryngeal dystonia revealing IBGC. Her healthy parents' CT scans were both normal. We identified in the proband a new nonsense mutation in exon 4 of PDGFB, c.439C>T (p.Gln147*), which was absent from the parents' DNA. This mutation may result in a loss-of-function of PDGF-B, which has been shown to cause IBGC in humans and to disrupt the blood-brain barrier in mice, resulting in brain calcification. The c.439C>T mutation is located between two previously reported nonsense mutations, c.433C>T (p.Gln145*) and c.445C>T (p.Arg149*), on a region that could be a hot spot for de novo mutations. We present the first full demonstration of the de novo occurrence of an IBGC-causative mutation in a sporadic case.

  3. NMD Microarray Analysis for Rapid Genome-Wide Screen of Mutated Genes in Cancer

    Directory of Open Access Journals (Sweden)

    Maija Wolf

    2005-01-01

    Full Text Available Gene mutations play a critical role in cancer development and progression, and their identification offers possibilities for accurate diagnostics and therapeutic targeting. Finding genes undergoing mutations is challenging and slow, even in the post-genomic era. A new approach was recently developed by Noensie and Dietz to prioritize and focus the search, making use of nonsense-mediated mRNA decay (NMD inhibition and microarray analysis (NMD microarrays in the identification of transcripts containing nonsense mutations. We combined NMD microarrays with array-based CGH (comparative genomic hybridization in order to identify inactivation of tumor suppressor genes in cancer. Such a “mutatomics” screening of prostate cancer cell lines led to the identification of inactivating mutations in the EPHB2 gene. Up to 8% of metastatic uncultured prostate cancers also showed mutations of this gene whose loss of function may confer loss of tissue architecture. NMD microarray analysis could turn out to be a powerful research method to identify novel mutated genes in cancer cell lines, providing targets that could then be further investigated for their clinical relevance and therapeutic potential.

  4. Identification of a novel WFS1 homozygous nonsense mutation in Jordanian children with Wolfram syndrome.

    Science.gov (United States)

    Bodoor, Khaldon; Batiha, Osama; Abu-Awad, Ayman; Al-Sarihin, Khaldon; Ziad, Haya; Jarun, Yousef; Abu-Sheikha, Aya; Abu Jalboush, Sara; Alibrahim, Khoulod S

    2016-09-01

    Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disorder characterized by the presentation of early onset type I diabetes mellitus and optic atrophy with later onset diabetes insipidus and deafness. WFS1 gene was identified on chromosome 4p16.1 as the gene responsible for WS disease given that most of the WS patients were found to carry mutations in this gene. This study was carried out to investigate the molecular spectrum of WFS1 gene in Jordanian families. Molecular and clinical characterization was performed on five WS patients from two unrelated Jordanian families. Our data indicated that WS patients of the first family harbored two deletion mutations (V415del and F247fs) located in exon 8 and exon 7 respectively, with a compound heterozygous pattern of inheritance; while in the second family, we identified a novel nonsense mutation (W185X) located in exon 5 in the N-terminal cytoplasmic domain with a homozygous pattern of inheritance. This mutation can be considered as loss of function mutation since the resulting truncated protein lost both the transmembrane domain and the C-terminal domain. Additionally, the W185X mutation lies within the CaM binding domain in wolframin protein which is thought to have a role in the regulation of wolframin function in response to calcium levels.

  5. Refractory macrocytic anemias in patients with clonal hematopoietic disorders and isolated mutations of the spliceosome gene ZRSR2.

    Science.gov (United States)

    Fleischman, Roger A; Stockton, Shannon S; Cogle, Christopher R

    2017-10-01

    Although mutations in RNA splicing genes occur frequently in patients with clonal cytopenias of unknown significance (CCUS) and myelodysplastic syndromes (MDS), very often additional common myeloid gene driver mutations are present at diagnosis. Thus, the clinical significance of isolated mutations in the most commonly mutated RNA splicing genes remains unknown. Here we report five unusual patients with an isolated mutation causing a loss of function of ZRSR2, a protein required for recognition of a functional 3' splice site. Two of the patients had a diagnosis of CCUS and three patients had an MDS disorder characterized by low risk features and absence of complex cytogenetic abnor-malities. Notably, all five cases were characterized predominantly by macrocytic anemia. In addition, one CCUS patient followed for more than 15 years with a transfusion dependent macrocytic anemia was found to have an inactivating ZRSR2 mutation with an allele frequency of >60%. We conclude that the common clinical features of patients with an isolated mutation of ZRSR2 are a macrocytic anemia without leukopenia, thrombocytopenia or an increase in marrow blast percentage. At least in some cases, the presence of an isolated ZRSR2 mutation can accompany a dominant hematopoietic clone with a low risk for transformation to frank dysplasia or acute leukemia. Copyright © 2017. Published by Elsevier Ltd.

  6. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  7. Reduction of antinutritional glucosinolates in Brassica oilseeds by mutation of genes encoding transporters

    DEFF Research Database (Denmark)

    Nour-Eldin, Hussam Hassan; Madsen, Svend Roesen; Engelen, Steven

    2017-01-01

    -of-function phenotypes into Brassica crops is challenging because Brassica is polyploid. We mutated one of seven and four of 12 GTR orthologs and reduced glucosinolate levels in seeds by 60-70% in two different Brassica species (Brassica rapa and Brassica juncea). Reduction in seed glucosinolates was stably inherited......The nutritional value of Brassica seed meals is reduced by the presence of glucosinolates, which are toxic compounds involved in plant defense. Mutation of the genes encoding two glucosinolate transporters (GTRs) eliminated glucosinolates from Arabidopsis thaliana seeds, but translation of loss...... over multiple generations and maintained in field trials of two mutant populations at three locations. Successful translation of the gtr loss-of-function phenotype from model plant to two Brassica crops suggests that our transport engineering approach could be broadly applied to reduce seed...

  8. Mutations in the GABA Transporter SLC6A1 Cause Epilepsy with Myoclonic-Atonic Seizures

    Science.gov (United States)

    Carvill, Gemma L.; McMahon, Jacinta M.; Schneider, Amy; Zemel, Matthew; Myers, Candace T.; Saykally, Julia; Nguyen, John; Robbiano, Angela; Zara, Federico; Specchio, Nicola; Mecarelli, Oriano; Smith, Robert L.; Leventer, Richard J.; Møller, Rikke S.; Nikanorova, Marina; Dimova, Petia; Jordanova, Albena; Petrou, Steven; Helbig, Ingo; Striano, Pasquale; Weckhuysen, Sarah; Berkovic, Samuel F.; Scheffer, Ingrid E.; Mefford, Heather C.

    2015-01-01

    GAT-1, encoded by SLC6A1, is one of the major gamma-aminobutyric acid (GABA) transporters in the brain and is responsible for re-uptake of GABA from the synapse. In this study, targeted resequencing of 644 individuals with epileptic encephalopathies led to the identification of six SLC6A1 mutations in seven individuals, all of whom have epilepsy with myoclonic-atonic seizures (MAE). We describe two truncations and four missense alterations, all of which most likely lead to loss of function of GAT-1 and thus reduced GABA re-uptake from the synapse. These individuals share many of the electrophysiological properties of Gat1-deficient mice, including spontaneous spike-wave discharges. Overall, pathogenic mutations occurred in 6/160 individuals with MAE, accounting for ∼4% of unsolved MAE cases. PMID:25865495

  9. A cis-acting regulatory mutation causes premature hair graying and susceptibility to melanoma in the horse.

    Science.gov (United States)

    Rosengren Pielberg, Gerli; Golovko, Anna; Sundström, Elisabeth; Curik, Ino; Lennartsson, Johan; Seltenhammer, Monika H; Druml, Thomas; Binns, Matthew; Fitzsimmons, Carolyn; Lindgren, Gabriella; Sandberg, Kaj; Baumung, Roswitha; Vetterlein, Monika; Strömberg, Sara; Grabherr, Manfred; Wade, Claire; Lindblad-Toh, Kerstin; Pontén, Fredrik; Heldin, Carl-Henrik; Sölkner, Johann; Andersson, Leif

    2008-08-01

    In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses. The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.

  10. Simultaneous DNA and RNA mapping of somatic mitochondrial mutations across diverse human cancers

    DEFF Research Database (Denmark)

    Stewart, James B.; Alaei-Mahabadi, Babak; Radhakrishnan, Sabarinathan

    2015-01-01

    of evidence from both genomic and transcriptomic sequencing. We find that there is selective pressure against deleterious coding mutations, supporting that functional mitochondria are required in tumor cells, and also observe a strong mutational strand bias, compatible with endogenous replication...

  11. Mapping Mutations on Phylogenies

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2005-01-01

    This chapter provides a short review of recent methodologies developed for mapping mutations on phylogenies. Mapping of mutations, or character changes in general, using the maximum parsimony principle has been one of the most powerful tools in phylogenetics, and it has been used in a variety...... uncertainty in the mapping. Recently developed probabilistic methods can incorporate statistical uncertainty in the character mappings. In these methods, focus is on a probability distribution of mutational mappings instead of a single estimate of the mutational mapping....

  12. Contributions of intrinsic mutation rate and selfish selection to levels of de novo HRAS mutations in the paternal germline.

    Science.gov (United States)

    Giannoulatou, Eleni; McVean, Gilean; Taylor, Indira B; McGowan, Simon J; Maher, Geoffrey J; Iqbal, Zamin; Pfeifer, Susanne P; Turner, Isaac; Burkitt Wright, Emma M M; Shorto, Jennifer; Itani, Aysha; Turner, Karen; Gregory, Lorna; Buck, David; Rajpert-De Meyts, Ewa; Looijenga, Leendert H J; Kerr, Bronwyn; Wilkie, Andrew O M; Goriely, Anne

    2013-12-10

    The RAS proto-oncogene Harvey rat sarcoma viral oncogene homolog (HRAS) encodes a small GTPase that transduces signals from cell surface receptors to intracellular effectors to control cellular behavior. Although somatic HRAS mutations have been described in many cancers, germline mutations cause Costello syndrome (CS), a congenital disorder associated with predisposition to malignancy. Based on the epidemiology of CS and the occurrence of HRAS mutations in spermatocytic seminoma, we proposed that activating HRAS mutations become enriched in sperm through a process akin to tumorigenesis, termed selfish spermatogonial selection. To test this hypothesis, we quantified the levels, in blood and sperm samples, of HRAS mutations at the p.G12 codon and compared the results to changes at the p.A11 codon, at which activating mutations do not occur. The data strongly support the role of selection in determining HRAS mutation levels in sperm, and hence the occurrence of CS, but we also found differences from the mutation pattern in tumorigenesis. First, the relative prevalence of mutations in sperm correlates weakly with their in vitro activating properties and occurrence in cancers. Second, specific tandem base substitutions (predominantly GC>TT/AA) occur in sperm but not in cancers; genomewide analysis showed that this same mutation is also overrepresented in constitutional pathogenic and polymorphic variants, suggesting a heightened vulnerability to these mutations in the germline. We developed a statistical model to show how both intrinsic mutation rate and selfish selection contribute to the mutational burden borne by the paternal germline.

  13. Accelerated inactivation of the L-type calcium current due to a mutation in CACNB2b underlies Brugada syndrome

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Marieb, Mark; Pfeiffer, Ryan

    2009-01-01

    S in which loss of function is caused by accelerated inactivation of I(Ca). The proband, a 32 year old male, displayed a Type I ST segment elevation in two right precordial ECG leads following a procainamide challenge. EP study was positive with induction of polymorphic VT/VF. Interrogation of implanted ICD...... significantly faster in mutant channels between 0 and + 20 mV. Action potential voltage clamp experiments showed that total charge was reduced by almost half compared to WT. We report the first BrS mutation in CaCNB2b resulting in accelerated inactivation of L-type calcium channel current. Our results suggest...

  14. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  15. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  16. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  17. Bi-allelic Mutations in PKD1L1 Are Associated with Laterality Defects in Humans.

    Science.gov (United States)

    Vetrini, Francesco; D'Alessandro, Lisa C A; Akdemir, Zeynep C; Braxton, Alicia; Azamian, Mahshid S; Eldomery, Mohammad K; Miller, Kathryn; Kois, Chelsea; Sack, Virginia; Shur, Natasha; Rijhsinghani, Asha; Chandarana, Jignesh; Ding, Yan; Holtzman, Judy; Jhangiani, Shalini N; Muzny, Donna M; Gibbs, Richard A; Eng, Christine M; Hanchard, Neil A; Harel, Tamar; Rosenfeld, Jill A; Belmont, John W; Lupski, James R; Yang, Yaping

    2016-10-06

    Disruption of the establishment of left-right (L-R) asymmetry leads to situs anomalies ranging from situs inversus totalis (SIT) to situs ambiguus (heterotaxy). The genetic causes of laterality defects in humans are highly heterogeneous. Via whole-exome sequencing (WES), we identified homozygous mutations in PKD1L1 from three affected individuals in two unrelated families. PKD1L1 encodes a polycystin-1-like protein and its loss of function is known to cause laterality defects in mouse and medaka fish models. Family 1 had one fetus and one deceased child with heterotaxy and complex congenital heart malformations. WES identified a homozygous splicing mutation, c.6473+2_6473+3delTG, which disrupts the invariant splice donor site in intron 42, in both affected individuals. In the second family, a homozygous c.5072G>C (p.Cys1691Ser) missense mutation was detected in an individual with SIT and congenital heart disease. The p.Cys1691Ser substitution affects a highly conserved cysteine residue and is predicted by molecular modeling to disrupt a disulfide bridge essential for the proper folding of the G protein-coupled receptor proteolytic site (GPS) motif. Damaging effects associated with substitutions of this conserved cysteine residue in the GPS motif have also been reported in other genes, namely GPR56, BAI3, and PKD1 in human and lat-1 in C. elegans, further supporting the likely pathogenicity of p.Cys1691Ser in PKD1L1. The identification of bi-allelic PKD1L1 mutations recapitulates previous findings regarding phenotypic consequences of loss of function of the orthologous genes in mice and medaka fish and further expands our understanding of genetic contributions to laterality defects in humans. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  18. Characterization of novel StAR (steroidogenic acute regulatory protein mutations causing non-classic lipoid adrenal hyperplasia.

    Directory of Open Access Journals (Sweden)

    Christa E Flück

    Full Text Available CONTEXT: Steroidogenic acute regulatory protein (StAR is crucial for transport of cholesterol to mitochondria where biosynthesis of steroids is initiated. Loss of StAR function causes lipoid congenital adrenal hyperplasia (LCAH. OBJECTIVE: StAR gene mutations causing partial loss of function manifest atypical and may be mistaken as familial glucocorticoid deficiency. Only a few mutations have been reported. DESIGN: To report clinical, biochemical, genetic, protein structure and functional data on two novel StAR mutations, and to compare them with published literature. SETTING: Collaboration between the University Children's Hospital Bern, Switzerland, and the CIBERER, Hospital Vall d'Hebron, Autonomous University, Barcelona, Spain. PATIENTS: Two subjects of a non-consanguineous Caucasian family were studied. The 46,XX phenotypic normal female was diagnosed with adrenal insufficiency at the age of 10 months, had normal pubertal development and still has no signs of hypergonodatropic hypogonadism at 32 years of age. Her 46,XY brother was born with normal male external genitalia and was diagnosed with adrenal insufficiency at 14 months. Puberty was normal and no signs of hypergonadotropic hypogonadism are present at 29 years of age. RESULTS: StAR gene analysis revealed two novel compound heterozygote mutations T44HfsX3 and G221S. T44HfsX3 is a loss-of-function StAR mutation. G221S retains partial activity (∼30% and is therefore responsible for a milder, non-classic phenotype. G221S is located in the cholesterol binding pocket and seems to alter binding/release of cholesterol. CONCLUSIONS: StAR mutations located in the cholesterol binding pocket (V187M, R188C, R192C, G221D/S seem to cause non-classic lipoid CAH. Accuracy of genotype-phenotype prediction by in vitro testing may vary with the assays employed.

  19. Sexual selection, germline mutation rate and sperm competition.

    Science.gov (United States)

    Møller, A P; Cuervo, J J

    2003-04-18

    An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1) Increased sperm production associated with sperm competition may increase mutation rate. (2) Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously benefits viability alleles expressed in condition

  20. Sexual selection, germline mutation rate and sperm competition

    Directory of Open Access Journals (Sweden)

    Møller AP

    2003-04-01

    Full Text Available Abstract Background An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1 Increased sperm production associated with sperm competition may increase mutation rate. (2 Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. Results A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. Conclusion We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously

  1. ANGDelMut – a web-based tool for predicting and analyzing functional loss mechanisms of amyotrophic lateral sclerosis-associated angiogenin mutations [v2; ref status: indexed, http://f1000r.es/2mc

    Directory of Open Access Journals (Sweden)

    Aditya K Padhi

    2013-12-01

    Full Text Available ANGDelMut is a web-based tool for predicting the functional consequences of missense mutations in the angiogenin (ANG protein, which is associated with amyotrophic lateral sclerosis (ALS. Missense mutations in ANG result in loss of either ribonucleolytic activity or nuclear translocation activity or both of these functions, and in turn cause ALS. However, no web-based tools are available to predict whether a newly identified ANG mutation will possibly lead to ALS. More importantly, no web-implemented method is currently available to predict the mechanisms of loss-of-function(s of ANG mutants. In light of this observation, we developed the ANGDelMut web-based tool, which predicts whether an ANG mutation is deleterious or benign. The user selects certain attributes from the input panel, which serves as a query to infer whether a mutant will exhibit loss of ribonucleolytic activity or nuclear translocation activity or whether the overall stability will be affected. The output states whether the mutation is deleterious or benign, and if it is deleterious, gives the possible mechanism(s of loss-of-function. This web-based tool, freely available at http://bioschool.iitd.ernet.in/DelMut/, is the first of its kind to provide a platform for researchers and clinicians, to infer the functional consequences of ANG mutations and correlate their possible association with ALS ahead of experimental findings.

  2. ANGDelMut – a web-based tool for predicting and analyzing functional loss mechanisms of amyotrophic lateral sclerosis-associated angiogenin mutations [v3; ref status: indexed, http://f1000r.es/2yt

    Directory of Open Access Journals (Sweden)

    Aditya K Padhi

    2014-02-01

    Full Text Available ANGDelMut is a web-based tool for predicting the functional consequences of missense mutations in the angiogenin (ANG protein, which is associated with amyotrophic lateral sclerosis (ALS. Missense mutations in ANG result in loss of either ribonucleolytic activity or nuclear translocation activity or both of these functions, and in turn cause ALS. However, no web-based tools are available to predict whether a newly identified ANG mutation will possibly lead to ALS. More importantly, no web-implemented method is currently available to predict the mechanisms of loss-of-function(s of ANG mutants. In light of this observation, we developed the ANGDelMut web-based tool, which predicts whether an ANG mutation is deleterious or benign. The user selects certain attributes from the input panel, which serves as a query to infer whether a mutant will exhibit loss of ribonucleolytic activity or nuclear translocation activity or whether the overall stability will be affected. The output states whether the mutation is deleterious or benign, and if it is deleterious, gives the possible mechanism(s of loss-of-function. This web-based tool, freely available at http://bioschool.iitd.ernet.in/DelMut/, is the first of its kind to provide a platform for researchers and clinicians, to infer the functional consequences of ANG mutations and correlate their possible association with ALS ahead of experimental findings.

  3. A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy

    International Nuclear Information System (INIS)

    Zhang, Juanjuan; Yuan, Yimin; Lin, Bing; Feng, Hao; Li, Yan; Dai, Xianning; Zhou, Huihui; Dong, Xujie; Liu, Xiao-Ling; Guan, Min-Xin

    2012-01-01

    Highlights: ► We report the characterization of a four-generation large Chinese family with ADOA. ► We find a new heterozygous mutation c.C1198G in OPA1 gene which may be a novel pathogenic mutation in this pedigree. ► We do not find any mitochondrial DNA mutations associated with optic atrophy. ► Other factors may also contribute to the phenotypic variability of ADOA in this pedigree. -- Abstract: A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9 years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.

  4. A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Juanjuan; Yuan, Yimin; Lin, Bing; Feng, Hao; Li, Yan [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Dai, Xianning; Zhou, Huihui [Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, Zhejiang (China); Dong, Xujie [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Liu, Xiao-Ling, E-mail: lxl@mail.eye.ac.cn [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Guan, Min-Xin, E-mail: min-xin.guan@cchmc.org [Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, Zhejiang (China); Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310012 (China); Division of Human Genetics, Cincinnati Children' s Hospital Medical Center, OH 45229 (United States)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer We report the characterization of a four-generation large Chinese family with ADOA. Black-Right-Pointing-Pointer We find a new heterozygous mutation c.C1198G in OPA1 gene which may be a novel pathogenic mutation in this pedigree. Black-Right-Pointing-Pointer We do not find any mitochondrial DNA mutations associated with optic atrophy. Black-Right-Pointing-Pointer Other factors may also contribute to the phenotypic variability of ADOA in this pedigree. -- Abstract: A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9 years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.

  5. UV Signature Mutations

    Science.gov (United States)

    2014-01-01

    Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations – deviations from a random distribution of base changes to create a pattern typical of that mutagen – and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the non-transcribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; non-signature mutations induced by UV may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents. PMID:25354245

  6. Point mutations in GLI3 lead to misregulation of its subcellular localization.

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    Sybille Krauss

    Full Text Available BACKGROUND: Mutations in the transcription factor GLI3, a downstream target of Sonic Hedgehog (SHH signaling, are responsible for the development of malformation syndromes such as Greig-cephalopolysyndactyly-syndrome (GCPS, or Pallister-Hall-syndrome (PHS. Mutations that lead to loss of function of the protein and to haploinsufficiency cause GCPS, while truncating mutations that result in constitutive repressor function of GLI3 lead to PHS. As an exception, some point mutations in the C-terminal part of GLI3 observed in GCPS patients have so far not been linked to loss of function. We have shown recently that protein phosphatase 2A (PP2A regulates the nuclear localization and transcriptional activity a of GLI3 function. PRINCIPAL FINDINGS: We have shown recently that protein phosphatase 2A (PP2A and the ubiquitin ligase MID1 regulate the nuclear localization and transcriptional activity of GLI3. Here we show mapping of the functional interaction between the MID1-alpha4-PP2A complex and GLI3 to a region between amino acid 568-1100 of GLI3. Furthermore we demonstrate that GCPS-associated point mutations, that are located in that region, lead to misregulation of the nuclear GLI3-localization and transcriptional activity. GLI3 phosphorylation itself however appears independent of its localization and remains untouched by either of the point mutations and by PP2A-activity, which suggests involvement of an as yet unknown GLI3 interaction partner, the phosphorylation status of which is regulated by PP2A activity, in the control of GLI3 subcellular localization and activity. CONCLUSIONS: The present findings provide an explanation for the pathogenesis of GCPS in patients carrying C-terminal point mutations, and close the gap in our understanding of how GLI3-genotypes give rise to particular phenotypes. Furthermore, they provide a molecular explanation for the phenotypic overlap between Opitz syndrome patients with dysregulated PP2A-activity and

  7. nfxB as a novel target for analysis of mutation spectra in Pseudomonas aeruginosa.

    Science.gov (United States)

    Monti, Mariela R; Morero, Natalia R; Miguel, Virginia; Argaraña, Carlos E

    2013-01-01

    nfxB encodes a negative regulator of the mexCD-oprJ genes for drug efflux in the opportunistic pathogen Pseudomonas aeruginosa. Inactivating mutations in this transcriptional regulator constitute one of the main mechanisms of resistance to ciprofloxacin (Cip(r)). In this work, we evaluated the use of nfxB/Cip(r) as a new test system to study mutation spectra in P. aeruginosa. The analysis of 240 mutations in nfxB occurring spontaneously in the wild-type and mutator backgrounds or induced by mutagens showed that nfxB/Cip(r) offers several advantages compared with other mutation detection systems. Identification of nfxB mutations was easy since the entire open reading frame and its promoter region were sequenced from the chromosome using a single primer. Mutations detected in nfxB included all transitions and transversions, 1-bp deletions and insertions, >1-bp deletions and duplications. The broad mutation spectrum observed in nfxB relies on the selection of loss-of-function changes, as we confirmed by generating a structural model of the NfxB repressor and evaluating the significance of each detected mutation. The mutation spectra characterized in the mutS, mutT, mutY and mutM mutator backgrounds or induced by the mutagenic agents 2-aminopurine, cisplatin and hydrogen peroxide were in agreement with their predicted mutational specificities. Additionally, this system allowed the analysis of sequence context effects since point mutations occurred at 85 different sites distributed over the entire nfxB. Significant hotspots and preferred sequence contexts were observed for spontaneous and mutagen-induced mutation spectra. Finally, we demonstrated the utility of a luminescence-based reporter for identification of nfxB mutants previous to sequencing analysis. Thus, the nfxB/Cip(r) system in combination with the luminescent reporter may be a valuable tool for studying mutational processes in Pseudomonas spp. wherein the genes encoding the NfxB repressor and the associated

  8. nfxB as a novel target for analysis of mutation spectra in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Mariela R Monti

    Full Text Available nfxB encodes a negative regulator of the mexCD-oprJ genes for drug efflux in the opportunistic pathogen Pseudomonas aeruginosa. Inactivating mutations in this transcriptional regulator constitute one of the main mechanisms of resistance to ciprofloxacin (Cip(r. In this work, we evaluated the use of nfxB/Cip(r as a new test system to study mutation spectra in P. aeruginosa. The analysis of 240 mutations in nfxB occurring spontaneously in the wild-type and mutator backgrounds or induced by mutagens showed that nfxB/Cip(r offers several advantages compared with other mutation detection systems. Identification of nfxB mutations was easy since the entire open reading frame and its promoter region were sequenced from the chromosome using a single primer. Mutations detected in nfxB included all transitions and transversions, 1-bp deletions and insertions, >1-bp deletions and duplications. The broad mutation spectrum observed in nfxB relies on the selection of loss-of-function changes, as we confirmed by generating a structural model of the NfxB repressor and evaluating the significance of each detected mutation. The mutation spectra characterized in the mutS, mutT, mutY and mutM mutator backgrounds or induced by the mutagenic agents 2-aminopurine, cisplatin and hydrogen peroxide were in agreement with their predicted mutational specificities. Additionally, this system allowed the analysis of sequence context effects since point mutations occurred at 85 different sites distributed over the entire nfxB. Significant hotspots and preferred sequence contexts were observed for spontaneous and mutagen-induced mutation spectra. Finally, we demonstrated the utility of a luminescence-based reporter for identification of nfxB mutants previous to sequencing analysis. Thus, the nfxB/Cip(r system in combination with the luminescent reporter may be a valuable tool for studying mutational processes in Pseudomonas spp. wherein the genes encoding the NfxB repressor and

  9. PhoQ mutations promote lipid A modification and polymyxin resistance of Pseudomonas aeruginosa found in colistin-treated cystic fibrosis patients.

    Science.gov (United States)

    Miller, Amanda K; Brannon, Mark K; Stevens, Laurel; Johansen, Helle Krogh; Selgrade, Sara E; Miller, Samuel I; Høiby, Niels; Moskowitz, Samuel M

    2011-12-01

    Pseudomonas aeruginosa can develop resistance to polymyxin and other cationic antimicrobial peptides. Previous work has shown that mutations in the PmrAB and PhoPQ regulatory systems can confer low to moderate levels of polymyxin resistance (MICs of 8 to 64 mg/liter) in laboratory and clinical strains of this organism. To explore the role of PhoPQ in high-level clinical polymyxin resistance, P. aeruginosa strains with colistin MICs > 512 mg/liter that had been isolated from cystic fibrosis patients treated with inhaled colistin (polymyxin E) were analyzed. Probable loss-of-function phoQ alleles found in these cystic fibrosis strains conferred resistance to polymyxin. Partial and complete suppressor mutations in phoP were identified in some cystic fibrosis strains with resistance-conferring phoQ mutations, suggesting that additional loci can be involved in polymyxin resistance in P. aeruginosa. Disruption of chromosomal phoQ in the presence of an intact phoP allele stimulated 4-amino-l-arabinose addition to lipid A and induced transcription from the promoter of the pmrH (arnB) operon, consistent with the known role of this lipid A modification in polymyxin resistance. These results indicate that phoQ loss-of-function mutations can contribute to high-level polymyxin resistance in clinical strains of P. aeruginosa.

  10. Whole-exome sequencing reveals a heterozygous LRP5 mutation in a 6-year-old boy with vertebral compression fractures and low trabecular bone density.

    Science.gov (United States)

    Fahiminiya, Somayyeh; Majewski, Jacek; Roughley, Peter; Roschger, Paul; Klaushofer, Klaus; Rauch, Frank

    2013-11-01

    Juvenile osteoporosis (JO) is characterized by bone fragility during development, low bone mass and absence of extraskeletal features. Heterozygous loss-of-function mutations in LRP5 have been found in a few patients, but bone tissue and bone material abnormalities associated with such mutations have not been determined. Here we report on a 6-year-old boy who presented with a history of seven low-energy long-bone fractures starting at 19months of age and absence of extraskeletal involvement. Spine radiographs revealed multiple vertebral compression fractures. Despite tall stature (95th percentile), lumbar spine areal bone mineral density was low (z-score=-3.2). Trabecular volumetric bone mineral density, measured by peripheral quantitative computed tomography at the distal radius, was low (z-score=-5.1), but cortical thickness at the radial diaphysis was normal. Iliac bone histomorphometry demonstrated low bone formation activity in trabecular but not in cortical bone. Quantitative backscattered electron imaging showed normal material bone density in trabecular bone, but elevated results in the cortex. Whole-exome sequencing revealed a heterozygous insertion of a nucleotide in exon 12 of LRP5. This mutation had previously been reported in another JO patient and had been shown to lead to nonsense-mediated decay. Thus, heterozygous loss-of-function mutations in LRP5 can be associated with a bone formation deficit that affects mostly the trabecular compartment and can result in bone fragility during the first years of life. © 2013.

  11. Multi-institutional Oncogenic Driver Mutation Analysis in Lung Adenocarcinoma: The Lung Cancer Mutation Consortium Experience.

    Science.gov (United States)

    Sholl, Lynette M; Aisner, Dara L; Varella-Garcia, Marileila; Berry, Lynne D; Dias-Santagata, Dora; Wistuba, Ignacio I; Chen, Heidi; Fujimoto, Junya; Kugler, Kelly; Franklin, Wilbur A; Iafrate, A John; Ladanyi, Marc; Kris, Mark G; Johnson, Bruce E; Bunn, Paul A; Minna, John D; Kwiatkowski, David J

    2015-05-01

    Molecular genetic analyses of lung adenocarcinoma have recently become standard of care for treatment selection. The Lung Cancer Mutation Consortium was formed to enable collaborative multi-institutional analyses of 10 potential oncogenic driver mutations. Technical aspects of testing and clinicopathologic correlations are presented. Mutation testing in at least one of the eight genes (epidermal growth factor receptor [EGFR], KRAS, ERBB2, AKT1, BRAF, MEK1, NRAS, and PIK3CA) using SNaPshot, mass spectrometry, Sanger sequencing+/- peptide nucleic acid and/or sizing assays, along with anaplastic lymphoma kinase (ALK) and/or MET fluorescence in situ hybridization, were performed in six labs on 1007 patients from 14 institutions. In all, 1007 specimens had mutation analysis performed, and 733 specimens had all 10 genes analyzed. Mutation identification rates did not vary by analytic method. Biopsy and cytology specimens were inadequate for testing in 26% and 35% of cases compared with 5% of surgical specimens. Among the 1007 cases with mutation analysis performed, EGFR, KRAS, ALK, and ERBB2 alterations were detected in 22%, 25%, 8.5%, and 2.4% of cases, respectively. EGFR mutations were highly associated with female sex, Asian race, and never-smoking status; and less strongly associated with stage IV disease, presence of bone metastases, and absence of adrenal metastases. ALK rearrangements were strongly associated with never-smoking status and more weakly associated with presence of liver metastases. ERBB2 mutations were strongly associated with Asian race and never-smoking status. Two mutations were seen in 2.7% of samples, all but one of which involved one or more of PIK3CA, ALK, or MET. Multi-institutional molecular analysis across multiple platforms, sample types, and institutions can yield consistent results and novel clinicopathological observations.

  12. Carrier status for the common R501X and 2282del4 filaggrin mutations is not associated with hearing phenotypes in 5,377 children from the ALSPAC cohort.

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    Santiago Rodriguez

    2009-06-01

    Full Text Available Filaggrin is a major protein in the epidermis. Several mutations in the filaggrin gene (FLG have been associated with a number of conditions. Filaggrin is expressed in the tympanic membrane and could alter its mechanical properties, but the relationship between genetic variation in FLG and hearing has not yet been tested.We examined whether loss-of function mutations R501X and 2282del4 in the FLG gene affected hearing in children. Twenty eight hearing variables representing five different aspects of hearing at age nine years in 5,377 children from the Avon Longitudinal Study of Parents and Children (ALSPAC cohort were tested for association with these mutations. No evidence of association was found between R501X or 2282del4 (or overall FLG mutation carrier status and any of the hearing phenotypes analysed.In conclusion, carrier status for common filaggrin mutations does not affect hearing in children.

  13. Recessive mutations of TMC1 associated with moderate to severe hearing loss.

    Science.gov (United States)

    Imtiaz, Ayesha; Maqsood, Azra; Rehman, Atteeq U; Morell, Robert J; Holt, Jeffrey R; Friedman, Thomas B; Naz, Sadaf

    2016-04-01

    TMC1 encodes a protein required for the normal function of mechanically activated channels that enable sensory transduction in auditory and vestibular hair cells. TMC1 protein is localized at the tips of the hair cell stereocilia, the site of conventional mechanotransduction. In many populations, loss-of-function recessive mutations of TMC1 are associated with profound deafness across all frequencies tested. In six families reported here, variable moderate-to-severe or moderate-to-profound hearing loss co-segregated with STR (short tandem repeats) markers at the TMC1 locus DFNB7/11. Massively parallel and Sanger sequencing of genomic DNA revealed each family co-segregating hearing loss with a homozygous TMC1 mutation: two reported mutations (p.R34X and p.R389Q) and three novel mutations (p.S596R, p.N199I, and c.1404 + 1G > T). TMC1 cDNA sequence from affected subjects homozygous for the donor splice site transversion c.1404 + 1G > T revealed skipping of exon 16, deleting 60 amino acids from the TMC1 protein. Since the mutations in our study cause less than profound hearing loss, we speculate that there is hypo-functional TMC1 mechanotransduction channel activity and that other even less damaging variants of TMC1 may be associated with more common mild-to-severe sensorineural hearing loss.

  14. Identification of a novel mutation in an Indian patient with CAII deficiency syndrome

    Directory of Open Access Journals (Sweden)

    Shivaprasad C

    2010-01-01

    Full Text Available Carbonic anhydrase II (CAII deficiency syndrome characterized by osteopetrosis (OP, renal tubular acidosis (RTA, and cerebral calcifications is caused by mutations in the carbonic anhydrase 2 (CA2 gene. Severity of this disorder varies depending on the nature of the mutation and its effect on the protein. We present here, the clinical and radiographic details along with, results of mutational analysis of the CA2 gene in an individual clinically diagnosed with renal tubular acidosis, osteopetrosis and mental retardation and his family members to establish genotype-phenotype correlation. A novel homozygous deletion mutation c.251delT was seen in the patient resulting in a frameshift and a premature stop codon at amino acid position 90 generating a truncated protein leading to a complete loss of function and a consequential deficiency of the enzyme making this a pathogenic mutation. Confirmation of clinical diagnosis by molecular methods is essential as the clinical features of the CAII deficiency syndrome are similar to other forms of OP but the treatment modalities are different. Genetic confirmation of the diagnosis at an early age leads to the timely institution of therapy improving the growth potential, reduces other complications like fractures, and aids in providing prenatal testing and genetic counseling to the parents planning a pregnancy.

  15. Novel LRP5 gene mutation in a patient with osteoporosis-pseudoglioma syndrome.

    Science.gov (United States)

    Marques-Pinheiro, Alice; Levasseur, Régis; Cormier, Catherine; Bonneau, Jessica; Boileau, Catherine; Varret, Mathilde; Abifadel, Marianne; Allanore, Yannick

    2010-03-01

    Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive disorder characterised by severe juvenile-onset osteoporosis and congenital or early-onset blindness. This serious illness is due to mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) that is a major actor in pathways involved in bone remodelling. Here, we report a novel frameshift mutation identified in a 22 year-old Tunisian boy of a consanguineous family. This patient had low bone mineral density (BMD), experienced multiple fractures during childhood and suffered ocular alterations with blindness. Direct DNA sequencing showed a homozygous 5 base pair insertion in exon 5 of the LRP5 gene. This new mutation is located in the first EGF-like domain and gives rise to a truncated protein of 384 amino acids. The functional significance of this mutation clearly indicates a loss-of-function mutation of the LRP5 gene leading to the observed OPPG phenotype. Rheumatologists must be aware of LRP5 gene that in addition to being a major gene in the mendelian disease that is OPPG syndrome seems to be involved in osteoporosis in the general population through some of its polymorphisms. Copyright 2009 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  16. FGFR2 mutation in 46,XY sex reversal with craniosynostosis.

    Science.gov (United States)

    Bagheri-Fam, Stefan; Ono, Makoto; Li, Li; Zhao, Liang; Ryan, Janelle; Lai, Raymond; Katsura, Yukako; Rossello, Fernando J; Koopman, Peter; Scherer, Gerd; Bartsch, Oliver; Eswarakumar, Jacob V P; Harley, Vincent R

    2015-12-01

    Patients with 46,XY gonadal dysgenesis (GD) exhibit genital anomalies, which range from hypospadias to complete male-to-female sex reversal. However, a molecular diagnosis is made in only 30% of cases. Heterozygous mutations in the human FGFR2 gene cause various craniosynostosis syndromes including Crouzon and Pfeiffer, but testicular defects were not reported. Here, we describe a patient whose features we would suggest represent a new FGFR2-related syndrome, craniosynostosis with XY male-to-female sex reversal or CSR. The craniosynostosis patient was chromosomally XY, but presented as a phenotypic female due to complete GD. DNA sequencing identified the FGFR2c heterozygous missense mutation, c.1025G>C (p.Cys342Ser). Substitution of Cys342 by Ser or other amino acids (Arg/Phe/Try/Tyr) has been previously reported in Crouzon and Pfeiffer syndrome. We show that the 'knock-in' Crouzon mouse model Fgfr2c(C342Y/C342Y) carrying a Cys342Tyr substitution displays XY gonadal sex reversal with variable expressivity. We also show that despite FGFR2c-Cys342Tyr being widely considered a gain-of-function mutation, Cys342Tyr substitution in the gonad leads to loss of function, as demonstrated by sex reversal in Fgfr2c(C342Y/-) mice carrying the knock-in allele on a null background. The rarity of our patient suggests the influence of modifier genes which exacerbated the testicular phenotype. Indeed, patient whole exome analysis revealed several potential modifiers expressed in Sertoli cells at the time of testis determination in mice. In summary, this study identifies the first FGFR2 mutation in a 46,XY GD patient. We conclude that, in certain rare genetic contexts, maintaining normal levels of FGFR2 signaling is important for human testis determination. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Mutation predicts 40 million years of fly wing evolution.

    Science.gov (United States)

    Houle, David; Bolstad, Geir H; van der Linde, Kim; Hansen, Thomas F

    2017-08-24

    Mutation enables evolution, but the idea that adaptation is also shaped by mutational variation is controversial. Simple evolutionary hypotheses predict such a relationship if the supply of mutations constrains evolution, but it is not clear that constraints exist, and, even if they do, they may be overcome by long-term natural selection. Quantification of the relationship between mutation and phenotypic divergence among species will help to resolve these issues. Here we use precise data on over 50,000 Drosophilid fly wings to demonstrate unexpectedly strong positive relationships between variation produced by mutation, standing genetic variation, and the rate of evolution over the last 40 million years. Our results are inconsistent with simple constraint hypotheses because the rate of evolution is very low relative to what both mutational and standing variation could allow. In principle, the constraint hypothesis could be rescued if the vast majority of mutations are so deleterious that they cannot contribute to evolution, but this also requires the implausible assumption that deleterious mutations have the same pattern of effects as potentially advantageous ones. Our evidence for a strong relationship between mutation and divergence in a slowly evolving structure challenges the existing models of mutation in evolution.

  18. Pseudomonas toxin pyocyanin triggers autophagy: Implications for pathoadaptive mutations.

    Science.gov (United States)

    Yang, Zhong-Shan; Ma, Lan-Qing; Zhu, Kun; Yan, Jin-Yuan; Bian, Li; Zhang, Ke-Qin; Zou, Cheng-Gang

    2016-06-02

    Pseudomonas aeruginosa can establish life-long chronic infection in patients with cystic fibrosis by generating genetic loss-of-function mutations, which enhance fitness of the bacterium in the airways. However, the precise role of the pathoadaptive mutations in persistence in chronic airways infection remains largely unknown. Here we demonstrate that pyocyanin, a well-described P. aeruginosa virulence factor that plays an important role in the initial infection, promotes autophagy in bronchial epithelial cells. Disruption of phzM, which is required for pyocyanin biosynthesis, leads to a significant reduction in autophagy in Beas-2B cells and lung tissues. Pyocyanin-induced autophagy is mediated by the EIF2AK4/GCN2-EIF2S1/eIF2α-ATF4 pathway. Interestingly, rats infected with the phzMΔ mutant strain have high mortality rate and numbers of colony-forming units, compared to those infected with wild-type (WT) P. aeruginosa PA14 strain, during chronic P. aeruginosa infection. In addition, the phzMΔ mutant strain induces more extensive alveolar wall thickening than the WT strain in the pulmonary airways of rats. As autophagy plays an essential role in suppressing bacterial burden, our findings provide a detailed understanding of why reduction of pyocyanin production in P. aeruginosa in chronic airways infections has been associated with better host adaptation and worse outcomes in cystic fibrosis.

  19. Screening for germline DND1 mutations in testicular cancer patients

    NARCIS (Netherlands)

    Sijmons, R.H.; Vos, Y.J.; Herkert, J.C.; Bos, K.K.; Holzik, M.F.; Hoekstra-Weebers, J.E.; Hofstra, R.M.; Hoekstra, H.J.

    Although several observations suggest that a strong genetic predisposition to developing testicular germ cell tumors (TGCT) exists, no associated, highly penetrant germline mutations have been identified so far. In the 129/Sv mouse strain, a germline mutation in the DND1 gene has been shown to

  20. Structural studies of p53 inactivation by DNA-contact mutations and its rescue by suppressor mutations via alternative protein–DNA interactions

    Science.gov (United States)

    Eldar, Amir; Rozenberg, Haim; Diskin-Posner, Yael; Rohs, Remo; Shakked, Zippora

    2013-01-01

    A p53 hot-spot mutation found frequently in human cancer is the replacement of R273 by histidine or cysteine residues resulting in p53 loss of function as a tumor suppressor. These mutants can be reactivated by the incorporation of second-site suppressor mutations. Here, we present high-resolution crystal structures of the p53 core domains of the cancer-related proteins, the rescued proteins and their complexes with DNA. The structures show that inactivation of p53 results from the incapacity of the mutated residues to form stabilizing interactions with the DNA backbone, and that reactivation is achieved through alternative interactions formed by the suppressor mutations. Detailed structural and computational analysis demonstrates that the rescued p53 complexes are not fully restored in terms of DNA structure and its interface with p53. Contrary to our previously studied wild-type (wt) p53-DNA complexes showing non-canonical Hoogsteen A/T base pairs of the DNA helix that lead to local minor-groove narrowing and enhanced electrostatic interactions with p53, the current structures display Watson–Crick base pairs associated with direct or water-mediated hydrogen bonds with p53 at the minor groove. These findings highlight the pivotal role played by R273 residues in supporting the unique geometry of the DNA target and its sequence-specific complex with p53. PMID:23863845

  1. Novel SCARB2 mutation in action myoclonus-renal failure syndrome and evaluation of SCARB2 mutations in isolated AMRF features

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    Hopfner Franziska

    2011-10-01

    Full Text Available Abstract Background Action myoclonus-renal failure syndrome is a hereditary form of progressive myoclonus epilepsy associated with renal failure. It is considered to be an autosomal-recessive disease related to loss-of-function mutations in SCARB2. We studied a German AMRF family, additionally showing signs of demyelinating polyneuropathy and dilated cardiomyopathy. To test the hypothesis whether isolated appearance of individual AMRF syndrome features could be related to heterozygote SCARB2 mutations, we screened for SCARB2 mutations in unrelated patients showing isolated AMRF features. Methods In the AMRF family all exons of SCARB2 were analyzed by Sanger sequencing. The mutation screening of unrelated patients with isolated AMRF features affected by either epilepsy (n = 103, progressive myoclonus epilepsy or generalized epilepsy, demyelinating polyneuropathy (n = 103, renal failure (n = 192 or dilated cardiomyopathy (n = 85 was performed as high resolution melting curve analysis of the SCARB2 exons. Results A novel homozygous 1 bp deletion (c.111delC in SCARB2 was found by sequencing three affected homozygous siblings of the affected family. A heterozygous sister showed generalized seizures and reduction of nerve conduction velocity in her legs. No mutations were found in the epilepsy, renal failure or dilated cardiomyopathy samples. In the polyneuropathy sample two individuals with demyelinating disease were found to be carriers of a SCARB2 frameshift mutation (c.666delCCTTA. Conclusions Our findings indicate that demyelinating polyneuropathy and dilated cardiomyopathy are part of the action myoclonus-renal failure syndrome. Moreover, they raise the possibility that in rare cases heterozygous SCARB2 mutations may be associated with PNP features.

  2. Bioinformatics Study of Cancer-Related Mutations within p53 Phosphorylation Site Motifs

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    Xiaona Ji

    2014-07-01

    Full Text Available p53 protein has about thirty phosphorylation sites located at the N- and C-termini and in the core domain. The phosphorylation sites are relatively less mutated than other residues in p53. To understand why and how p53 phosphorylation sites are rarely mutated in human cancer, using a bioinformatics approaches, we examined the phosphorylation site and its nearby flanking residues, focusing on the consensus phosphorylation motif pattern, amino-acid correlations within the phosphorylation motifs, the propensity of structural disorder of the phosphorylation motifs, and cancer mutations observed within the phosphorylation motifs. Many p53 phosphorylation sites are targets for several kinases. The phosphorylation sites match 17 consensus sequence motifs out of the 29 classified. In addition to proline, which is common in kinase specificity-determining sites, we found high propensity of acidic residues to be adjacent to phosphorylation sites. Analysis of human cancer mutations in the phosphorylation motifs revealed that motifs with adjacent acidic residues generally have fewer mutations, in contrast to phosphorylation sites near proline residues. p53 phosphorylation motifs are mostly disordered. However, human cancer mutations within phosphorylation motifs tend to decrease the disorder propensity. Our results suggest that combination of acidic residues Asp and Glu with phosphorylation sites provide charge redundancy which may safe guard against loss-of-function mutations, and that the natively disordered nature of p53 phosphorylation motifs may help reduce mutational damage. Our results further suggest that engineering acidic amino acids adjacent to potential phosphorylation sites could be a p53 gene therapy strategy.

  3. Novel mutations affecting LRP5 splicing in patients with osteoporosis-pseudoglioma syndrome (OPPG).

    Science.gov (United States)

    Laine, C M; Chung, B D; Susic, M; Prescott, T; Semler, O; Fiskerstrand, T; D'Eufemia, P; Castori, M; Pekkinen, M; Sochett, E; Cole, W G; Netzer, C; Mäkitie, O

    2011-08-01

    Osteoporosis-pseudoglioma sydrome (OPPG) is an autosomal recessive disorder with early-onset severe osteoporosis and blindness, caused by biallelic loss-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. Heterozygous carriers exhibit a milder bone phenotype. Only a few splice mutations in LRP5 have been published. We present clinical and genetic data for four patients with novel LRP5 mutations, three of which affect splicing. Patients were evaluated clinically and by radiography and bone densitometry. Genetic screening of LRP5 was performed on the basis of the clinical diagnosis of OPPG. Splice aberrances were confirmed by cDNA sequencing or exon trapping. The effect of one splice mutation on LRP5 protein function was studied. A novel splice-site mutation c.1584+4A>T abolished the donor splice site of exon 7 and activated a cryptic splice site, which led to an in-frame insertion of 21 amino acids (p.E528_V529ins21). Functional studies revealed severely impaired signal transduction presumably caused by defective intracellular transport of the mutated receptor. Exon trapping was used on two samples to confirm that splice-site mutations c.4112-2A>G and c.1015+1G>T caused splicing-out of exons 20 and 5, respectively. One patient carried a homozygous deletion of exon 4 causing the loss of exons 4 and 5, as demonstrated by cDNA analysis. Our results broaden the spectrum of mutations in LRP5 and provide the first functional data on splice aberrations.

  4. Impact of heterozygous mutations in BRCA1 and BRCA2. Sensitivity to genotoxic drugs

    International Nuclear Information System (INIS)

    Delgado, L.; Grotiuz, G.; Lens, D.; Fresco, R.

    2004-01-01

    The carriers of heterozygous mutations in BRCA1 / 2 have a high risk of developing breast cancer. The loss of the normal allele with consequent loss of function is frequently observed in tumor level. Since these genes involved in the cellular response to genetic damage, loss of function can determine differences in sensitivity to genotoxic agents. In this study investigated whether heterozygous mutations in BRCA1 / 2 modify the sensitivity to genotoxic drugs using lymphoblastic cell lines developed from individuals who carry no mutation carriers and heterozygous for BRCA1 / 2. Materials and methods. Chemo sensitivity of the cell lines was compared lymphoblastoid GM13709 (mutation in exon 11 of BRCA1 2187delA), GM14622 (level 607stop mutation in exon 11 of BRCA2) and GM 14453 (normal BRCA1 / 2) from exposure to Adriamycin (0.2-2.5 mM) and Cisplatin (0.625- 80mM) through the test of cell viability based on MTT reduction. It determined the inhibitory concentration 50 (IC50) from curves regression dose-response obtained after 24 hours of drug exposure. It 5 independent experiments performed in triplicate. Results. The line GM14622 was significantly (P = 0.003) more sensitive to Adriamycin (IC50: 0.585 mM) than the Control GM14453 (IC50: 1.364 mM) online while GM13709 was similar to the control (IC50: 1.324 mM) response. Turn the line GM14622 was also significantly (P = 0.01) more sensitive cisplatin (IC50: 12.7 mM) than the line GM14453 (IC50: 28.6mm) and GM13709 had the same response as the (IC50: 28.6 mM) control. Discussion and Conclusions. Our results suggest that mutations deleterious heterozygous BRCA2 may confer increased sensitivity to drugs genotoxic, which may have implications in the management of patients carrying or BRCA2 mutations in women with sporadic breast cancer exhibit low expression of BRCA2

  5. Better plants through mutations

    International Nuclear Information System (INIS)

    1988-01-01

    This is a public relations film describing problems associated with the genetic improvement of crop plants through induced mutations. Mutations are the ultimate source of genetic variation in plants. Mutation induction is now established as a practical tool in plant breeding. The Joint FAO/IAEA Division and the IAEA's laboratory at Seibersdorf have supported research and practical implementation of mutation breeding of both seed propagated and vegetatively propagated plants. Plant biotechnology based on in vitro culture and recombinant DNA technology will make a further significant contribution to plant breeding

  6. Variable mutation rates as an adaptive strategy in replicator populations.

    Directory of Open Access Journals (Sweden)

    Michael Stich

    2010-06-01

    Full Text Available For evolving populations of replicators, there is much evidence that the effect of mutations on fitness depends on the degree of adaptation to the selective pressures at play. In optimized populations, most mutations have deleterious effects, such that low mutation rates are favoured. In contrast to this, in populations thriving in changing environments a larger fraction of mutations have beneficial effects, providing the diversity necessary to adapt to new conditions. What is more, non-adapted populations occasionally benefit from an increase in the mutation rate. Therefore, there is no optimal universal value of the mutation rate and species attempt to adjust it to their momentary adaptive needs. In this work we have used stationary populations of RNA molecules evolving in silico to investigate the relationship between the degree of adaptation of an optimized population and the value of the mutation rate promoting maximal adaptation in a short time to a new selective pressure. Our results show that this value can significantly differ from the optimal value at mutation-selection equilibrium, being strongly influenced by the structure of the population when the adaptive process begins. In the short-term, highly optimized populations containing little variability respond better to environmental changes upon an increase of the mutation rate, whereas populations with a lower degree of optimization but higher variability benefit from reducing the mutation rate to adapt rapidly. These findings show a good agreement with the behaviour exhibited by actual organisms that replicate their genomes under broadly different mutation rates.

  7. A mouse model of the human Fragile X syndrome I304N mutation.

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    Julie B Zang

    2009-12-01

    Full Text Available The mental retardation, autistic features, and behavioral abnormalities characteristic of the Fragile X mental retardation syndrome result from the loss of function of the RNA-binding protein FMRP. The disease is usually caused by a triplet repeat expansion in the 5'UTR of the FMR1 gene. This leads to loss of function through transcriptional gene silencing, pointing to a key function for FMRP, but precluding genetic identification of critical activities within the protein. Moreover, antisense transcripts (FMR4, ASFMR1 in the same locus have been reported to be silenced by the repeat expansion. Missense mutations offer one means of confirming a central role for FMRP in the disease, but to date, only a single such patient has been described. This patient harbors an isoleucine to asparagine mutation (I304N in the second FMRP KH-type RNA-binding domain, however, this single case report was complicated because the patient harbored a superimposed familial liver disease. To address these issues, we have generated a new Fragile X Syndrome mouse model in which the endogenous Fmr1 gene harbors the I304N mutation. These mice phenocopy the symptoms of Fragile X Syndrome in the existing Fmr1-null mouse, as assessed by testicular size, behavioral phenotyping, and electrophysiological assays of synaptic plasticity. I304N FMRP retains some functions, but has specifically lost RNA binding and polyribosome association; moreover, levels of the mutant protein are markedly reduced in the brain specifically at a time when synapses are forming postnatally. These data suggest that loss of FMRP function, particularly in KH2-mediated RNA binding and in synaptic plasticity, play critical roles in pathogenesis of the Fragile X Syndrome and establish a new model for studying the disorder.

  8. Association of a bitter taste receptor mutation with Balkan Endemic Nephropathy (BEN

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    Wooding Stephen P

    2012-10-01

    Full Text Available Abstract Background Balkan Endemic Nephropathy (BEN is late-onset kidney disease thought to arise from chronic exposure to aristolochic acid, a phytotoxin that contaminates wheat supplies in rural areas of Eastern Europe. It has recently been demonstrated that humans are capable of perceiving aristolochic acid at concentrations below 40 nM as the result of high-affinity interactions with the TAS2R43 bitter taste receptor. Further, TAS2R43 harbors high-frequency loss-of-function mutations resulting in 50-fold variability in perception. This suggests that genetic variation in TAS2R43 might affect susceptibility to BEN, with individuals carrying functional forms of the receptor being protected by an ability to detect tainted foods. Methods To determine whether genetic variation in TAS2R43 predicts BEN susceptibility, we examined genotype-phenotype associations in a case–control study. A cohort of 88 affected and 99 control subjects from western Bulgaria were genotyped with respect to two key missense variants and a polymorphic whole-gene deletion of TAS2R43 (W35S, H212R, and wt/Δ, which are known to affect taste sensitivity to aristolochic acid. Tests for association between haplotypes and BEN status were then performed. Results Three major TAS2R43 haplotypes observed in previous studies (TAS2R43-W35/H212, -S35/R212 and –Δ were present at high frequencies (0.17, 0.36, and 0.47 respectively in our sample, and a significant association between genotype and BEN status was present (P = 0.020; odds ratio 1.18. However, contrary to expectation, BEN was positively associated with TAS2R43-W35/H212, a highly responsive allele previously shown to confer elevated bitter sensitivity to aristolochic acid, which should drive aversion but might also affect absorption, altering toxin activation. Conclusions Our findings are at strong odds with the prediction that carriers of functional alleles of TAS2R43 are protected from BEN by an ability to detect and

  9. Conditional Function of Autoaggregative Protein Cah and Common cah Mutations in Shiga Toxin-Producing Escherichia coli.

    Science.gov (United States)

    Carter, Michelle Qiu; Brandl, Maria T; Kudva, Indira T; Katani, Robab; Moreau, Matthew R; Kapur, Vivek

    2018-01-01

    autotransporter protein Cah confers on E. coli DH5α cells a strong autoaggregative phenotype that is inversely correlated with its ability to form biofilms and plays a strain-specific role in plant and animal colonization by STEC. Although cah is widespread in the STEC population, we detected a mutation rate of 31.3% in cah , which is similar to that reported for rpoS and fimH The formation of cell aggregates due to increased bacterium-to-bacterium interactions may be disadvantageous to bacterial populations under conditions that favor a planktonic state in STEC. Therefore, a loss-of-function mutation in cah is likely a selective trait in STEC when autoaggregative properties become detrimental to bacterial cells and may contribute to the adaptability of STEC to fluctuating environments. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

  10. Homozygous Desmocollin-2 Mutations and Arrhythmogenic Cardiomyopathy.

    Science.gov (United States)

    Lorenzon, Alessandra; Pilichou, Kalliopi; Rigato, Ilaria; Vazza, Giovanni; De Bortoli, Marzia; Calore, Martina; Occhi, Gianluca; Carturan, Elisa; Lazzarini, Elisabetta; Cason, Marco; Mazzotti, Elisa; Poloni, Giulia; Mostacciuolo, Maria Luisa; Daliento, Luciano; Thiene, Gaetano; Corrado, Domenico; Basso, Cristina; Bauce, Barbara; Rampazzo, Alessandra

    2015-10-15

    Dominant mutations in desmocollin-2 (DSC2) gene cause arrhythmogenic cardiomyopathy (ACM), a progressive heart muscle disease characterized by ventricular tachyarrhythmias, heart failure, and risk of juvenile sudden death. Recessive mutations are rare and are associated with a cardiac or cardiocutaneous phenotype. Here, we evaluated the impact of a homozygous founder DSC2 mutation on clinical expression of ACM. An exon-by-exon analysis of the DSC2 coding region was performed in 94 ACM index patients. The c.536A>G (p.D179G) mutation was identified in 5 patients (5.3%), 4 of which resulted to be homozygous carriers. The 5 subjects shared a conserved haplotype, strongly indicating a common founder. Genetic and clinical investigation of probands' families revealed that p.D179G homozygous carriers displayed severe forms of biventricular cardiomyopathy without hair or skin abnormalities. The only heterozygous proband, who carried an additional variant of unknown significance in αT-catenin gene, showed a mild form of ACM without left ventricular involvement. All heterozygous family members were clinically asymptomatic. In conclusion, this is the first homozygous founder mutation in DSC2 gene identified among Italian ACM probands. Our findings provide further evidence of the occurrence of recessive DSC2 mutations in patients with ACM predominantly presenting with biventricular forms of the disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. A missense mutation in melanocortin 1 receptor is associated with the red coat colour in donkeys.

    Science.gov (United States)

    Abitbol, M; Legrand, R; Tiret, L

    2014-12-01

    The seven donkey breeds recognised by the French studbook are characterised by few coat colours: black, bay and grey. Normand bay donkeys seldom give birth to red foals, a colour more commonly seen and recognised in American miniature donkeys. Red resembles the equine chestnut colour, previously attributed to a mutation in the melanocortin 1 receptor gene (MC1R). We used a panel of 124 donkeys to identify a recessive missense c.629T>C variant in MC1R that showed a perfect association with the red coat colour. This variant leads to a methionine to threonine substitution at position 210 in the protein. We showed that methionine 210 is highly conserved among vertebrate melanocortin receptors. Previous in silico and in vitro analyses predicted this residue to lie within a functional site. Our in vivo results emphasised the pivotal role played by this residue, the alteration of which yielded a phenotype fully compatible with a loss of function of MC1R. We thus propose to name the c.629T>C allele in donkeys the e allele, which further enlarges the panel of recessive MC1R loss-of-function alleles described in animals and humans. © 2014 Stichting International Foundation for Animal Genetics.

  12. Multiple nevoid basal cell carcinoma syndrome associated with congenital orbital teratoma, caused by a PTCH1 frameshift mutation.

    Science.gov (United States)

    Rodrigues, A L; Carvalho, A; Cabral, R; Carneiro, V; Gilardi, P; Duarte, C P; Puente-Prieto, J; Santos, P; Mota-Vieira, L

    2014-07-25

    Gorlin-Goltz syndrome, or nevoid basal cell carcinoma syndrome (NBCCS), is a rare autosomal dominant disorder caused by mutations in the PTCH1 gene and shows a high level of penetrance and variable expressivity. The syndrome is characterized by developmental abnormalities or neoplasms and is diagnosed with 2 major criteria, or with 1 major and 2 minor criteria. Here, we report a new clinical manifestation associated with this syndrome in a boy affected by NBCCS who had congenital orbital teratoma at birth. Later, at the age of 15 years, he presented with 4 major and 4 minor criteria of NBCCS, including multiple basal cell carcinoma and 2 odontogenic keratocysts of the jaw, both confirmed by histology, more than 5 palmar pits, calcification of the cerebral falx, extensive meningeal calcifications, macrocephaly, hypertelorism, frontal bosses, and kyphoscoliosis. PTCH1 mutation analysis revealed the heterozygous germline mutation c.290dupA. This mutation generated a frameshift within exon 2 and an early premature stop codon (p.Asn97LysfsX43), predicting a truncated protein with complete loss of function. Identification of this mutation is useful for genetic counseling. Although the clinical symptoms are well-known, our case contributes to the understanding of phenotypic variability in NBCCS, highlighting that PTCH1 mutations cannot be used for predicting disease burden and reinforces the need of a multidisciplinary team in the diagnosis, treatment, and follow-up of NBCCS patients.

  13. Mutations in two large pedigrees highlight the role of ZNF711 in X-linked intellectual disability.

    Science.gov (United States)

    van der Werf, Ilse M; Van Dijck, Anke; Reyniers, Edwin; Helsmoortel, Céline; Kumar, Ajay Anand; Kalscheuer, Vera M; de Brouwer, Arjan Pm; Kleefstra, Tjitske; van Bokhoven, Hans; Mortier, Geert; Janssens, Sandra; Vandeweyer, Geert; Kooy, R Frank

    2017-03-20

    Intellectual disability (ID) affects approximately 1-2% of the general population and is characterized by impaired cognitive abilities. ID is both clinically as well as genetically heterogeneous, up to 2000 genes are estimated to be involved in the emergence of the disease with various clinical presentations. For many genes, only a few patients have been reported and causality of some genes has been questioned upon the discovery of apparent loss-of-function mutations in healthy controls. Description of additional patients strengthens the evidence for the involvement of a gene in the disease and can clarify the clinical phenotype associated with mutations in a particular gene. Here, we present two large four-generation families with a total of 11 males affected with ID caused by mutations in ZNF711, thereby expanding the total number of families with ID and a ZNF711 mutation to four. Patients with mutations in ZNF711 all present with mild to moderate ID and poor speech accompanied by additional features in some patients, including autistic features and mild facial dysmorphisms, suggesting that ZNF711 mutations cause non-syndromic ID. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Absence of mutations in the coding sequence of the potential tumor suppressor 3pK in metastatic melanoma

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    Houben Roland

    2005-12-01

    Full Text Available Abstract Background Activation of Ras or Raf contributes to tumorigenesis of melanoma. However, constitutive Raf activation is also a characteristic of the majority of benign melanocytic nevi and high intensity signaling of either Ras or Raf was found to induce growth inhibition and senescence rather than transformation. Since the chromosome 3p kinase (3pK is a target of the Ras/Raf/Mek/Erk signaling pathway which antagonizes the function of the oncogene and anti-differentiation factor Bmi-1, 3pK may function as a tumor suppressor in tumors with constitutive Ras/Raf activation. Consequently, we tested whether inactivating 3pK mutations are present in melanoma. Methods 30 metastatic melanoma samples, which were positive for activating mutations of either BRaf or NRas, were analyzed for possible mutations in the 3pk gene. The 10 coding exons and their flanking intron sequences were amplified by PCR and direct sequencing of the PCR products was performed. Results This analysis revealed that besides the presence of some single nucleotide polymorphisms in the 3pk gene, we could not detect any possible loss of function mutation in any of these 30 metastatic melanoma samples selected for the presence of activating mutations within the Ras/Raf/Mek/Erk signaling pathway. Conclusion Hence, in melanoma with constitutively active Ras/Raf inactivating mutations within the 3pk gene do not contribute to the oncogenic phenotype of this highly malignant tumor.

  15. Two Families with Normosmic Congenital Hypogonadotropic Hypogonadism and Biallelic Mutations in KISS1R (KISS1 Receptor): Clinical Evaluation and Molecular Characterization of a Novel Mutation

    Science.gov (United States)

    Francou, Bruno; Fagart, Jérôme; Roussel, Ronan; Viengchareun, Say; Combettes, Laurent; Brailly-Tabard, Sylvie; Lombès, Marc; Young, Jacques; Guiochon-Mantel, Anne

    2013-01-01

    Context KISS1R mutations have been reported in few patients with normosmic congenital hypogonadotropic hypogonadism (nCHH) (OMIM #146110). Objective To describe in detail nCHH patients with biallelic KISS1R mutations belonging to 2 unrelated families, and to functionally characterize a novel KISS1R mutation. Results An original mutant, p.Tyr313His, was found in the homozygous state in 3 affected kindred (2 females and 1 male) from a consanguineous Portuguese family. This mutation, located in the seventh transmembrane domain, affects a highly conserved amino acid, perturbs the conformation of the transmembrane segment, and impairs MAP kinase signaling and intracellular calcium release. In the second family, a French Caucasian male patient with nCHH was found to carry two recurrent mutations in the compound heterozygous state (p.Leu102Pro/Stop399Arg). In this man, pulsatile GnRH (Gonadotropin Releasing Hormone) administration restored pulsatile LH (Luteinizing Hormone) secretion and testicular hormone secretion. Later, long-term combined gonadotropin therapy induced spermatogenesis, enabling 3 successive pregnancies that resulted in 2 miscarriages and the birth of a healthy boy. Conclusion We show that a novel loss-of-function mutation (p.Tyr313His) in the KISS1R gene can cause familial nCHH, revealing the crucial role of this amino acid in KISS1R function. The observed restoration of gonadotropin secretion by exogenous GnRH administration further supports, in humans, the hypothalamic origin of the gonadotropin deficiency in this genetic form of nCHH. PMID:23349759

  16. Two families with normosmic congenital hypogonadotropic hypogonadism and biallelic mutations in KISS1R (KISS1 receptor: clinical evaluation and molecular characterization of a novel mutation.

    Directory of Open Access Journals (Sweden)

    Frédéric Brioude

    Full Text Available CONTEXT: KISS1R mutations have been reported in few patients with normosmic congenital hypogonadotropic hypogonadism (nCHH (OMIM #146110. OBJECTIVE: To describe in detail nCHH patients with biallelic KISS1R mutations belonging to 2 unrelated families, and to functionally characterize a novel KISS1R mutation. RESULTS: An original mutant, p.Tyr313His, was found in the homozygous state in 3 affected kindred (2 females and 1 male from a consanguineous Portuguese family. This mutation, located in the seventh transmembrane domain, affects a highly conserved amino acid, perturbs the conformation of the transmembrane segment, and impairs MAP kinase signaling and intracellular calcium release. In the second family, a French Caucasian male patient with nCHH was found to carry two recurrent mutations in the compound heterozygous state (p.Leu102Pro/Stop399Arg. In this man, pulsatile GnRH (Gonadotropin Releasing Hormone administration restored pulsatile LH (Luteinizing Hormone secretion and testicular hormone secretion. Later, long-term combined gonadotropin therapy induced spermatogenesis, enabling 3 successive pregnancies that resulted in 2 miscarriages and the birth of a healthy boy. CONCLUSION: We show that a novel loss-of-function mutation (p.Tyr313His in the KISS1R gene can cause familial nCHH, revealing the crucial role of this amino acid in KISS1R function. The observed restoration of gonadotropin secretion by exogenous GnRH administration further supports, in humans, the hypothalamic origin of the gonadotropin deficiency in this genetic form of nCHH.

  17. Mutations in DZIP1L, which encodes a ciliary transition zone protein, cause autosomal recessive polycystic kidney disease

    Science.gov (United States)

    Lu, Hao; Galeano, Maria C. Rondón; Ott, Elisabeth; Kaeslin, Geraldine; Kausalya, P. Jaya; Kramer, Carina; Ortiz-Brüchle, Nadina; Hilger, Nadescha; Metzis, Vicki; Hiersche, Milan; Tay, Shang Yew; Tunningley, Robert; Vij, Shubha; Courtney, Andrew D.; Whittle, Belinda; Wühl, Elke; Vester, Udo; Hartleben, Björn; Neuber, Steffen; Frank, Valeska; Little, Melissa H.; Epting, Daniel; Papathanasiou, Peter; Perkins, Andrew C.; Wright, Graham D.; Hunziker, Walter; Gee, Heon Yung; Otto, Edgar A.; Zerres, Klaus; Hildebrandt, Friedhelm; Roy, Sudipto; Wicking, Carol; Bergmann, Carsten

    2017-01-01

    Autosomal recessive polycystic kidney disease (ARPKD), usually considered to be a genetically homogeneous disease caused by mutations in PKHD1, has been associated with ciliary dysfunction. Here, we describe mutations in the DAZ interacting protein 1-like (DZIP1L) gene in patients with ARPKD, findings we have further validated by loss-of-function studies in mice and zebrafish. DZIP1L localizes to centrioles and at the distal end of basal bodies, and interacts with septin2, a protein implicated in maintenance of the periciliary diffusion barrier at the ciliary transition zone. Consistent with a defect in the diffusion barrier, we found that the ciliary membrane translocation of the PKD proteins, polycystin-1 and −2, is compromised in DZIP1L mutant cells. Together, these data provide the first conclusive evidence that ARPKD is not a homogeneous disorder, and establishes DZIP1L as a second gene involved in its pathogenesis. PMID:28530676

  18. Mutations in DZIP1L, which encodes a ciliary-transition-zone protein, cause autosomal recessive polycystic kidney disease.

    Science.gov (United States)

    Lu, Hao; Galeano, Maria C Rondón; Ott, Elisabeth; Kaeslin, Geraldine; Kausalya, P Jaya; Kramer, Carina; Ortiz-Brüchle, Nadina; Hilger, Nadescha; Metzis, Vicki; Hiersche, Milan; Tay, Shang Yew; Tunningley, Robert; Vij, Shubha; Courtney, Andrew D; Whittle, Belinda; Wühl, Elke; Vester, Udo; Hartleben, Björn; Neuber, Steffen; Frank, Valeska; Little, Melissa H; Epting, Daniel; Papathanasiou, Peter; Perkins, Andrew C; Wright, Graham D; Hunziker, Walter; Gee, Heon Yung; Otto, Edgar A; Zerres, Klaus; Hildebrandt, Friedhelm; Roy, Sudipto; Wicking, Carol; Bergmann, Carsten

    2017-07-01

    Autosomal recessive polycystic kidney disease (ARPKD), usually considered to be a genetically homogeneous disease caused by mutations in PKHD1, has been associated with ciliary dysfunction. Here, we describe mutations in DZIP1L, which encodes DAZ interacting protein 1-like, in patients with ARPKD. We further validated these findings through loss-of-function studies in mice and zebrafish. DZIP1L localizes to centrioles and to the distal ends of basal bodies, and interacts with septin2, a protein implicated in maintenance of the periciliary diffusion barrier at the ciliary transition zone. In agreement with a defect in the diffusion barrier, we found that the ciliary-membrane translocation of the PKD proteins polycystin-1 and polycystin-2 is compromised in DZIP1L-mutant cells. Together, these data provide what is, to our knowledge, the first conclusive evidence that ARPKD is not a homogeneous disorder and further establish DZIP1L as a second gene involved in ARPKD pathogenesis.

  19. Diagnosis of Xeroderma pigmentosum variant in a young patient with two novel mutations in the POLH gene.

    Science.gov (United States)

    De Palma, Armando; Morren, Marie-Anne; Ged, Cécile; Pouvelle, Caroline; Taïeb, Alain; Aoufouchi, Said; Sarasin, Alain

    2017-09-01

    We describe the characterization of Xeroderma Pigmentosum variant (XPV) in a young Caucasian patient with phototype I, who exhibited a high sensitivity to sunburn and multiple cutaneous tumors at the age of 15 years. Two novel mutations in the POLH gene, which encodes the translesion DNA polymerase η, with loss of function due to two independent exon skippings, are reported to be associated as a compound heterozygous state in the patient. Western blot analysis performed on proteins from dermal fibroblasts derived from the patient and analysis of the mutation spectrum on immunoglobulin genes produced during the somatic hypermutation process in his memory B cells, show the total absence of translesion polymerase η activity in the patient. The total lack of Polη activity, necessary to bypass in an error-free manner UVR-induced pyrimidine dimers following sun exposure, explains the early unusual clinical appearance of this patient. © 2017 Wiley Periodicals, Inc.

  20. Identification and functional analysis of a novel mutation in the PAX3 gene associated with Waardenburg syndrome type I.

    Science.gov (United States)

    Niu, Zhijie; Li, Jiada; Tang, Fen; Sun, Jie; Wang, Xueping; Jiang, Lu; Mei, Lingyun; Chen, Hongsheng; Liu, Yalan; Cai, Xinzhang; Feng, Yong; He, Chufeng

    2018-02-05

    Waardenburg syndrome type 1 (WS1) is a rare autosomal dominant genetic disorder of neural crest cells (NCC) characterized by congenital sensorineural hearing loss, dystopia canthorum, and abnormal iris pigmentation. WS1 is due to loss-of-function mutations in paired box gene 3 (PAX3). Here, we identified a novel PAX3 mutation (c.808C>G, p.R270G) in a three-generation Chinese family with WS1, and then analyzed its in vitro activities. The R270G PAX3 retained nuclear distribution and normal DNA-binding ability; however, it failed to activate MITF promoter, suggesting that haploinsufficiency may be the underlying mechanism for the mild WS1 phenotype of the study family. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A Novel FOXE1 Mutation (R73S) in Bamforth–Lazarus Syndrome Causing Increased Thyroidal Gene Expression

    Science.gov (United States)

    Carré, Aurore; Hamza, Rasha T.; Kariyawasam, Dulanjalee; Guillot, Loïc; Teissier, Raphaël; Tron, Elodie; Castanet, Mireille; Dupuy, Corinne; El Kholy, Mohamed; Polak, Michel

    2014-01-01

    Background: Homozygous loss-of-function mutations in the FOXE1 gene have been reported in several patients with partial or complete Bamforth–Lazarus syndrome: congenital hypothyroidism (CH) with thyroid dysgenesis (usually athyreosis), cleft palate, spiky hair, with or without choanal atresia, and bifid epiglottis. Here, our objective was to evaluate potential functional consequences of a FOXE1 mutation in a patient with a similar clinical phenotype. Methods: FOXE1 was sequenced in eight patients with thyroid dysgenesis and cleft palate. Transient transfection was performed in HEK293 cells using the thyroglobulin (TG) and thyroid peroxidase (TPO) promoters in luciferase reporter plasmids to assess the functional impact of the FOXE1 mutations. Primary human thyrocytes transfected with wild type and mutant FOXE1 served to assess the impact of the mutation on endogenous TG and TPO expression. Results: We identified and characterized the function of a new homozygous FOXE1 missense mutation (p.R73S) in a boy with a typical phenotype (athyreosis, cleft palate, and partial choanal atresia). This new mutation located within the forkhead domain was inherited from the heterozygous healthy consanguineous parents. In vitro functional studies in HEK293 cells showed that this mutant gene enhanced the activity of the TG and TPO gene promoters (1.5-fold and 1.7-fold respectively vs. wild type FOXE1; p<0.05), unlike the five mutations previously reported in Bamforth–Lazarus syndrome. The gain-of-function effect of the FOXE1-p.R73S mutant gene was confirmed by an increase in endogenous TG production in primary human thyrocytes. Conclusion: We identified a new homozygous FOXE1 mutation responsible for enhanced expression of the TG and TPO genes in a boy whose phenotype is similar to that reported previously in patients with loss-of-function FOXE1 mutations. This finding further delineates the role for FOXE1 in both thyroid and palate development, and shows that enhanced gene

  2. Mutations in G protein-coupled receptors that impact receptor trafficking and reproductive function.

    Science.gov (United States)

    Ulloa-Aguirre, Alfredo; Zariñán, Teresa; Dias, James A; Conn, P Michael

    2014-01-25

    G protein coupled receptors (GPCRs) are a large superfamily of integral cell surface plasma membrane proteins that play key roles in transducing extracellular signals, including sensory stimuli, hormones, neurotransmitters, or paracrine factors into the intracellular environment through the activation of one or more heterotrimeric G proteins. Structural alterations provoked by mutations or variations in the genes coding for GPCRs may lead to misfolding, altered plasma membrane expression of the receptor protein and frequently to disease. A number of GPCRs regulate reproductive function at different levels; these receptors include the gonadotropin-releasing hormone receptor (GnRHR) and the gonadotropin receptors (follicle-stimulating hormone receptor and luteinizing hormone receptor), which regulate the function of the pituitary-gonadal axis. Loss-of-function mutations in these receptors may lead to hypogonadotropic or hypergonadotropic hypogonadism, which encompass a broad spectrum of clinical phenotypes. In this review we describe mutations that provoke misfolding and failure of these receptors to traffick from the endoplasmic reticulum to the plasma membrane. We also discuss some aspects related to the therapeutic potential of some target-specific drugs that selectively bind to and rescue function of misfolded mutant GnRHR and gonadotropin receptors, and that represent potentially valuable strategies to treat diseases caused by inactivating mutations of these receptors. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Next-Gen Sequencing Exposes Frequent MED12 Mutations and Actionable Therapeutic Targets in Phyllodes Tumors

    Science.gov (United States)

    Cani, Andi K.; Hovelson, Daniel H.; McDaniel, Andrew S.; Sadis, Seth; Haller, Michaela J.; Yadati, Venkata; Amin, Anmol M.; Bratley, Jarred; Bandla, Santhoshi; Williams, Paul D.; Rhodes, Kate; Liu, Chia-Jen; Quist, Michael J.; Rhodes, Daniel R.; Grasso, Catherine S.; Kleer, Celina G.; Tomlins, Scott A.

    2016-01-01

    Phyllodes tumors are rare fibroepithelial tumors with variable clinical behavior accounting for a small subset of all breast neoplasms, yet little is known about the genetic alterations that drive tumor initiation and/or progression. Here targeted next generation sequencing (NGS) was used to identify somatic alterations in formalin fixed paraffin embedded (FFPE) patient specimens from malignant, borderline and benign cases. NGS revealed mutations in mediator complex subunit 12 (MED12) affecting the G44 hotspot residue in the majority (67%) of cases spanning all three histological grades. In addition, loss-of-function mutations in p53 (TP53) as well as deleterious mutations in the tumor suppressors retinoblastoma (RB1) and neurofibromin 1 (NF1) were identified exclusively in malignant tumors. High-level copy number alterations (CNAs) were nearly exclusively confined to malignant tumors, including potentially clinically actionable gene amplifications in IGF1R and EGFR. Taken together, this study defines the genomic landscape underlying phyllodes tumor development, suggests potential molecular correlates to histologic grade, expands the spectrum of human tumors with frequent recurrent MED12 mutations, and identifies IGF1R and EGFR as potential therapeutic targets in malignant cases. PMID:25593300

  4. Homozygous and compound-heterozygous mutations in TGDS cause Catel-Manzke syndrome.

    Science.gov (United States)

    Ehmke, Nadja; Caliebe, Almuth; Koenig, Rainer; Kant, Sarina G; Stark, Zornitza; Cormier-Daire, Valérie; Wieczorek, Dagmar; Gillessen-Kaesbach, Gabriele; Hoff, Kirstin; Kawalia, Amit; Thiele, Holger; Altmüller, Janine; Fischer-Zirnsak, Björn; Knaus, Alexej; Zhu, Na; Heinrich, Verena; Huber, Celine; Harabula, Izabela; Spielmann, Malte; Horn, Denise; Kornak, Uwe; Hecht, Jochen; Krawitz, Peter M; Nürnberg, Peter; Siebert, Reiner; Manzke, Hermann; Mundlos, Stefan

    2014-12-04

    Catel-Manzke syndrome is characterized by Pierre Robin sequence and a unique form of bilateral hyperphalangy causing a clinodactyly of the index finger. We describe the identification of homozygous and compound heterozygous mutations in TGDS in seven unrelated individuals with typical Catel-Manzke syndrome by exome sequencing. Six different TGDS mutations were detected: c.892A>G (p.Asn298Asp), c.270_271del (p.Lys91Asnfs(∗)22), c.298G>T (p.Ala100Ser), c.294T>G (p.Phe98Leu), c.269A>G (p.Glu90Gly), and c.700T>C (p.Tyr234His), all predicted to be disease causing. By using haplotype reconstruction we showed that the mutation c.298G>T is probably a founder mutation. Due to the spectrum of the amino acid changes, we suggest that loss of function in TGDS is the underlying mechanism of Catel-Manzke syndrome. TGDS (dTDP-D-glucose 4,6-dehydrogenase) is a conserved protein belonging to the SDR family and probably plays a role in nucleotide sugar metabolism. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  5. A recurrent de novo mutation in KCNC1 causes progressive myoclonus epilepsy

    DEFF Research Database (Denmark)

    Muona, M.; Berkovic, S. F.; Dibbens, L. M.

    2015-01-01

    Progressive myoclonus epilepsies (PMEs) are a group of rare, inherited disorders manifesting with action myoclonus, tonicclonic seizures and ataxia. We sequenced the exomes of 84 unrelated individuals with PME of unknown cause and molecularly solved 26 cases (31%). Remarkably, a recurrent de novo...... mutation, c. 959G>A (p.Arg320His), in KCNC1 was identified as a new major cause for PME. Eleven unrelated exome-sequenced (13%) and two affected individuals in a secondary cohort (7%) had this mutation. KCNC1 encodes K(V)3.1, a subunit of the K(V)3 voltage-gated potassium ion channels, which are major...... determinants of high-frequency neuronal firing. Functional analysis of the Arg320His mutant channel showed a dominant-negative loss-of-function effect. Ten cases had pathogenic mutations in known PME-associated genes (NEU1, NHLRC1, AFG3L2, EPM2A, CLN6 and SERPINI1). Identification of mutations in PRNP, SACS...

  6. Nine Novel PAX9 Mutations and a Distinct Tooth Agenesis Genotype-Phenotype.

    Science.gov (United States)

    Wong, S-W; Han, D; Zhang, H; Liu, Y; Zhang, X; Miao, M Z; Wang, Y; Zhao, N; Zeng, L; Bai, B; Wang, Y-X; Liu, H; Frazier-Bowers, S A; Feng, H

    2018-02-01

    Tooth agenesis is one of the most common developmental anomalies affecting function and esthetics. The paired-domain transcription factor, Pax9, is critical for patterning and morphogenesis of tooth and taste buds. Mutations of PAX9 have been identified in patients with tooth agenesis. Despite significant progress in the genetics of tooth agenesis, many gaps in knowledge exist in refining the genotype-phenotype correlation between PAX9 and tooth agenesis. In the present study, we complete genetic and phenotypic characterization of multiplex Chinese families with nonsyndromic (NS) tooth agenesis. Direct sequencing of polymerase chain reaction products revealed 9 novel (c.140G>C, c.167T>A, c.332G>C, c.194C>A, c.271A>T, c.146delC, c.185_189dup, c.256_262dup, and c.592delG) and 2 known heterozygous mutations in the PAX9 gene among 120 probands. Subsequently, pedigrees were extended, and we confirmed that the mutations co-segregated with the tooth agenesis phenotype (with exception of families in which DNA analysis was not available). In 1 family ( n = 6), 2 individuals harbored both the PAX9 c.592delG mutation and a heterozygous missense mutation (c.739C>T) in the MSX1 gene. Clinical characterization of families segregating a PAX9 mutation reveal that all affected individuals were missing the mandibular second molar and their maxillary central incisors are most susceptible to microdontia. A significant reduction of bitter taste perception was documented in individuals harboring PAX9 mutations ( n = 3). Functional studies revealed that PAX9 haploinsufficiency or a loss of function of the PAX9 protein underlies tooth agenesis.

  7. Novel mutations in EVC cause aberrant splicing in Ellis-van Creveld syndrome.

    Science.gov (United States)

    Shi, Lisong; Luo, Chunyan; Ahmed, Mairaj K; Attaie, Ali B; Ye, Xiaoqian

    2016-04-01

    Ellis-van Creveld syndrome (EvC) is a rare autosomal recessive disorder characterized by disproportionate chondrodysplasia, postaxial polydactyly, nail dystrophy, dental abnormalities and in a proportion of patients, congenital cardiac malformations. Weyers acrofacial dysostosis (Weyers) is another dominantly inherited disorder allelic to EvC syndrome but with milder phenotypes. Both disorders can result from loss-of-function mutations in either EVC or EVC2 gene, and phenotypes associated with the two gene mutations are clinically indistinguishable. We present here a clinical and molecular analysis of a Chinese family manifested specific features of EvC syndrome. Sequencing of both EVC and EVC2 identified two novel heterozygous splice site mutations c.384+5G>C in intron 3 and c.1465-1G>A in intron 10 in EVC, which were inherited from mother and father, respectively. In vitro minigene expression assay, RT-PCR and sequencing analysis demonstrated that c.384+5G>C mutation abolished normal splice site and created a new cryptic acceptor site within exon 4, whereas c.1465-1G>A mutation affected consensus splice junction site and resulted in full exon 11 skipping. These two aberrant pre-mRNA splicing processes both produced in-frame abnormal transcripts that possibly led to abolishment of important functional domains. To our knowledge, this is the first report of EVC mutations that cause EvC syndrome in Chinese population. Our data revealed that EVC splice site mutations altered splicing pattern and helped elucidate the pathogenesis of EvC syndrome.

  8. Characterization of a de novo SCN8A mutation in a patient with epileptic encephalopathy.

    Science.gov (United States)

    de Kovel, Carolien G F; Meisler, Miriam H; Brilstra, Eva H; van Berkestijn, Frederique M C; van 't Slot, Ruben; van Lieshout, Stef; Nijman, Isaac J; O'Brien, Janelle E; Hammer, Michael F; Estacion, Mark; Waxman, Stephen G; Dib-Hajj, Sulayman D; Koeleman, Bobby P C

    2014-11-01

    Recently, de novo SCN8A missense mutations have been identified as a rare dominant cause of epileptic encephalopathies (EIEE13). Functional studies on the first described case demonstrated gain-of-function effects of the mutation. We describe a novel de novo mutation of SCN8A in a patient with epileptic encephalopathy, and functional characterization of the mutant protein. Whole exome sequencing was used to discover the variant. We generated a mutant cDNA, transfected HEK293 cells, and performed Western blotting to assess protein stability. To study channel functional properties, patch-clamp experiments were carried out in transfected neuronal ND7/23 cells. The proband exhibited seizure onset at 6 months of age, diffuse brain atrophy, and more profound developmental impairment than the original case. The mutation p.Arg233Gly in the voltage sensing transmembrane segment D1S4 was present in the proband and absent in both parents. This mutation results in a temperature-sensitive reduction in protein expression as well as reduced sodium current amplitude and density and a relative increased response to a slow ramp stimulus, though this did not result in an absolute increased current at physiological temperatures. The new de novo SCN8A mutation is clearly deleterious, resulting in an unstable protein with reduced channel activity. This differs from the gain-of-function attributes of the first SCN8A mutation in epileptic encephalopathy, pointing to heterogeneity of mechanisms. Since Nav1.6 is expressed in both excitatory and inhibitory neurons, a differential effect of a loss-of-function of Nav1.6 Arg223Gly on inhibitory interneurons may underlie the epilepsy phenotype in this patient. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Optimized p53 immunohistochemistry is an accurate predictor of TP53 mutation in ovarian carcinoma.

    Science.gov (United States)

    Köbel, Martin; Piskorz, Anna M; Lee, Sandra; Lui, Shuhong; LePage, Cecile; Marass, Francesco; Rosenfeld, Nitzan; Mes Masson, Anne-Marie; Brenton, James D

    2016-10-01

    TP53 mutations are ubiquitous in high-grade serous ovarian carcinomas (HGSOC), and the presence of TP53 mutation discriminates between high and low-grade serous carcinomas and is now an important biomarker for clinical trials targeting mutant p53. p53 immunohistochemistry (IHC) is widely used as a surrogate for TP53 mutation but its accuracy has not been established. The objective of this study was to test whether improved methods for p53 IHC could reliably predict TP53 mutations independently identified by next generation sequencing (NGS). Four clinical p53 IHC assays and tagged-amplicon NGS for TP53 were performed on 171 HGSOC and 80 endometrioid carcinomas (EC). p53 expression was scored as overexpression (OE), complete absence (CA), cytoplasmic (CY) or wild type (WT). p53 IHC was evaluated as a binary classifier where any abnormal staining predicted deleterious TP53 mutation and as a ternary classifier where OE, CA or WT staining predicted gain-of-function (GOF or nonsynonymous), loss-of-function (LOF including stopgain, indel, splicing) or no detectable TP53 mutations (NDM), respectively. Deleterious TP53 mutations were detected in 169/171 (99%) HGSOC and 7/80 (8.8%) EC. The overall accuracy for the best performing IHC assay for binary and ternary prediction was 0.94 and 0.91 respectively, which improved to 0.97 (sensitivity 0.96, specificity 1.00) and 0.95 after secondary analysis of discordant cases. The sensitivity for predicting LOF mutations was lower at 0.76 because p53 IHC detected mutant p53 protein in 13 HGSOC with LOF mutations. CY staining associated with LOF was seen in 4 (2.3%) of HGSOC. Optimized p53 IHC can approach 100% specificity for the presence of TP53 mutation and its high negative predictive value is clinically useful as it can exclude the possibility of a low-grade serous tumour. 4.1% of HGSOC cases have detectable WT staining while harboring a TP53 LOF mutation, which limits sensitivity for binary prediction of mutation to 96%.

  10. Mutations in CDC45, Encoding an Essential Component of the Pre-initiation Complex, Cause Meier-Gorlin Syndrome and Craniosynostosis.

    Science.gov (United States)

    Fenwick, Aimee L; Kliszczak, Maciej; Cooper, Fay; Murray, Jennie; Sanchez-Pulido, Luis; Twigg, Stephen R F; Goriely, Anne; McGowan, Simon J; Miller, Kerry A; Taylor, Indira B; Logan, Clare; Bozdogan, Sevcan; Danda, Sumita; Dixon, Joanne; Elsayed, Solaf M; Elsobky, Ezzat; Gardham, Alice; Hoffer, Mariette J V; Koopmans, Marije; McDonald-McGinn, Donna M; Santen, Gijs W E; Savarirayan, Ravi; de Silva, Deepthi; Vanakker, Olivier; Wall, Steven A; Wilson, Louise C; Yuregir, Ozge Ozalp; Zackai, Elaine H; Ponting, Chris P; Jackson, Andrew P; Wilkie, Andrew O M; Niedzwiedz, Wojciech; Bicknell, Louise S

    2016-07-07

    DNA replication precisely duplicates the genome to ensure stable inheritance of genetic information. Impaired licensing of origins of replication during the G1 phase of the cell cycle has been implicated in Meier-Gorlin syndrome (MGS), a disorder defined by the triad of short stature, microtia, and a/hypoplastic patellae. Biallelic partial loss-of-function mutations in multiple components of the pre-replication complex (preRC; ORC1, ORC4, ORC6, CDT1, or CDC6) as well as de novo stabilizing mutations in the licensing inhibitor, GMNN, cause MGS. Here we report the identification of mutations in CDC45 in 15 affected individuals from 12 families with MGS and/or craniosynostosis. CDC45 encodes a component of both the pre-initiation (preIC) and CMG helicase complexes, required for initiation of DNA replication origin firing and ongoing DNA synthesis during S-phase itself, respectively, and hence is functionally distinct from previously identified MGS-associated genes. The phenotypes of affected individuals range from syndromic coronal craniosynostosis to severe growth restriction, fulfilling diagnostic criteria for Meier-Gorlin syndrome. All mutations identified were biallelic and included synonymous mutations altering splicing of physiological CDC45 transcripts, as well as amino acid substitutions expected to result in partial loss of function. Functionally, mutations reduce levels of full-length transcripts and protein in subject cells, consistent with partial loss of CDC45 function and a predicted limited rate of DNA replication and cell proliferation. Our findings therefore implicate the preIC as an additional protein complex involved in the etiology of MGS and connect the core cellular machinery of genome replication with growth, chondrogenesis, and cranial suture homeostasis. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  11. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  12. A hERG mutation E1039X produced a synergistic lesion on IKstogether with KCNQ1-R174C mutation in a LQTS family with three compound mutations.

    Science.gov (United States)

    Wu, Jie; Mizusawa, Yuka; Ohno, Seiko; Ding, Wei-Guang; Higaki, Takashi; Wang, Qi; Kohjitani, Hirohiko; Makiyama, Takeru; Itoh, Hideki; Toyoda, Futoshi; James, Andrew F; Hancox, Jules C; Matsuura, Hiroshi; Horie, Minoru

    2018-02-15

    Congenital long QT syndrome (LQTS) caused by compound mutations is usually associated with more severe clinical phenotypes. We identified a LQTS family harboring three compound mutations in different genes (KCNQ1-R174C, hERG-E1039X and SCN5A-E428K). KCNQ1-R174C, hERG-E1039X and SCN5A-E428K mutations and/or relevant wild-type (WT) cDNAs were respectively expressed in mammalian cells. I Ks -like, I Kr -like, I Na -like currents and the functional interaction between KCNQ1-R174C and hERG-E1039X channels were studied using patch-clamp and immunocytochemistry techniques. (1) Expression of KCNQ1-R174C alone showed no I Ks . Co-expression of KCNQ1-WT + KCNQ1-R174C caused a loss-of-function in I Ks and blunted the activation of I Ks in response to isoproterenol. (2) Expression of hERG-E1039X alone and co-expression of hERG-WT + hERG-E1039X negatively shifted inactivation curves and decelerated the recovery time from inactivation. (3) Expression of SCN5A-E428K increased peak I Na , but had no effect on late I Na . (4) I Ks and I Kr interact, and hERG-E1039X caused a loss-of-function in I Ks . (5) Immunocytochemical studies indicated that KCNQ1-R174C is trafficking defective and hERG-E1039X is defective in biosynthesis/degradation, but the abnormities were rescued by co-expression with WT. Thus, KCNQ1-R174C and hERG-E1039X disrupted I Ks and I Kr functions, respectively. The synergistic lesion, caused by KCNQ1-R174C and hERG-E1039X in I Ks , is very likely why patients showed more severe phenotypes in the compound mutation case.

  13. Induced mutation of soy by ionization mutation

    Energy Technology Data Exchange (ETDEWEB)

    Li, C.L.; Hsu, H.L.

    1975-09-01

    This article presents the results of experiments dealing with how 14 different doses of three types of ionization irradiation-roentgen rays, /sup 60/Co gamma rays, and thermal neutrons affect mutation of 14 types of soy beans and their hybrids. It was learned that with an increased dose the coefficient of seed germination decreases, the cotyledon becomes increasingly thicker, shoots develop more and more slowly, various deformities arise in the stalk, and fertility decreases. As far as M/sub 2/ mutation is concerned, a great variety has been discovered with regard to the height of the stem, the leaf formation, the color of the bloom, the color of the edge, the characteristics of the pod, the size of the seed and the color of the cicatrix. At the same time some specific characteristics having an important economic significance are being revealed, as for example, dwarf stems, the ability to withstand lodging, great pod density, increased inflorescence and short sprouts.

  14. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  15. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.

    1995-01-01

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  16. Strong-back safety latch

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  17. Mutations in SLC12A5 in epilepsy of infancy with migrating focal seizures

    Science.gov (United States)

    Stödberg, Tommy; McTague, Amy; Ruiz, Arnaud J.; Hirata, Hiromi; Zhen, Juan; Long, Philip; Farabella, Irene; Meyer, Esther; Kawahara, Atsuo; Vassallo, Grace; Stivaros, Stavros M.; Bjursell, Magnus K.; Stranneheim, Henrik; Tigerschiöld, Stephanie; Persson, Bengt; Bangash, Iftikhar; Das, Krishna; Hughes, Deborah; Lesko, Nicole; Lundeberg, Joakim; Scott, Rod C.; Poduri, Annapurna; Scheffer, Ingrid E.; Smith, Holly; Gissen, Paul; Schorge, Stephanie; Reith, Maarten E. A.; Topf, Maya; Kullmann, Dimitri M.; Harvey, Robert J.; Wedell, Anna; Kurian, Manju A.

    2015-01-01

    The potassium-chloride co-transporter KCC2, encoded by SLC12A5, plays a fundamental role in fast synaptic inhibition by maintaining a hyperpolarizing gradient for chloride ions. KCC2 dysfunction has been implicated in human epilepsy, but to date, no monogenic KCC2-related epilepsy disorders have been described. Here we show recessive loss-of-function SLC12A5 mutations in patients with a severe infantile-onset pharmacoresistant epilepsy syndrome, epilepsy of infancy with migrating focal seizures (EIMFS). Decreased KCC2 surface expression, reduced protein glycosylation and impaired chloride extrusion contribute to loss of KCC2 activity, thereby impairing normal synaptic inhibition and promoting neuronal excitability in this early-onset epileptic encephalopathy. PMID:26333769

  18. GNB5 Mutations Cause an Autosomal-Recessive Multisystem Syndrome with Sinus Bradycardia and Cognitive Disability.

    Science.gov (United States)

    Lodder, Elisabeth M; De Nittis, Pasquelena; Koopman, Charlotte D; Wiszniewski, Wojciech; Moura de Souza, Carolina Fischinger; Lahrouchi, Najim; Guex, Nicolas; Napolioni, Valerio; Tessadori, Federico; Beekman, Leander; Nannenberg, Eline A; Boualla, Lamiae; Blom, Nico A; de Graaff, Wim; Kamermans, Maarten; Cocciadiferro, Dario; Malerba, Natascia; Mandriani, Barbara; Akdemir, Zeynep Hande Coban; Fish, Richard J; Eldomery, Mohammad K; Ratbi, Ilham; Wilde, Arthur A M; de Boer, Teun; Simonds, William F; Neerman-Arbez, Marguerite; Sutton, V Reid; Kok, Fernando; Lupski, James R; Reymond, Alexandre; Bezzina, Connie R; Bakkers, Jeroen; Merla, Giuseppe

    2016-09-01

    GNB5 encodes the G protein β subunit 5 and is involved in inhibitory G protein signaling. Here, we report mutations in GNB5 that are associated with heart-rate disturbance, eye disease, intellectual disability, gastric problems, hypotonia, and seizures in nine individuals from six families. We observed an association between the nature of the variants and clinical severity; individuals with loss-of-function alleles had more severe symptoms, including substantial developmental delay, speech defects, severe hypotonia, pathological gastro-esophageal reflux, retinal disease, and sinus-node dysfunction, whereas related heterozygotes harboring missense variants presented with a clinically milder phenotype. Zebrafish gnb5 knockouts recapitulated the phenotypic spectrum of affected individuals, including cardiac, neurological, and ophthalmological abnormalities, supporting a direct role of GNB5 in the control of heart rate, hypotonia, and vision. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  19. Mutations in GABRB3

    DEFF Research Database (Denmark)

    Møller, Rikke S; Wuttke, Thomas V; Helbig, Ingo

    2017-01-01

    OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing...... of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. RESULTS: We identified 22 patients with heterozygous mutations in GABRB3, including 3...... probands from multiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy with myoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies...

  20. Mutation breeding in peas

    International Nuclear Information System (INIS)

    Jaranowski, J.; Micke, A.

    1985-01-01

    The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

  1. Comprehensive investigation of CASK mutations and other genetic etiologies in 41 patients with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH.

    Directory of Open Access Journals (Sweden)

    Shin Hayashi

    Full Text Available The CASK gene (Xp11.4 is highly expressed in the mammalian nervous system and plays several roles in neural development and synaptic function. Loss-of-function mutations of CASK are associated with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH, especially in females. Here, we present a comprehensive investigation of 41 MICPCH patients, analyzed by mutational search of CASK and screening of candidate genes using an SNP array, targeted resequencing and whole-exome sequencing (WES. In total, we identified causative or candidate genomic aberrations in 37 of the 41 cases (90.2%. CASK aberrations including a rare mosaic mutation in a male patient, were found in 32 cases, and a mutation in ITPR1, another known gene in which mutations are causative for MICPCH, was found in one case. We also found aberrations involving genes other than CASK, such as HDAC2, MARCKS, and possibly HS3ST5, which may be associated with MICPCH. Moreover, the targeted resequencing screening detected heterozygous variants in RELN in two cases, of uncertain pathogenicity, and WES analysis suggested that concurrent mutations of both DYNC1H1 and DCTN1 in one case could lead to MICPCH. Our results not only identified the etiology of MICPCH in nearly all the investigated patients but also suggest that MICPCH is a genetically heterogeneous condition, in which CASK inactivating mutations appear to account for the majority of cases.

  2. The Presenilin-1 ΔE9 Mutation Results in Reduced γ-Secretase Activity, but Not Total Loss of PS1 Function, in Isogenic Human Stem Cells

    Directory of Open Access Journals (Sweden)

    Grace Woodruff

    2013-11-01

    Full Text Available Presenilin 1 (PS1 is the catalytic core of γ-secretase, which cleaves type 1 transmembrane proteins, including the amyloid precursor protein (APP. PS1 also has γ-secretase-independent functions, and dominant PS1 missense mutations are the most common cause of familial Alzheimer’s disease (FAD. Whether PS1 FAD mutations are gain- or loss-of-function remains controversial, primarily because most studies have relied on overexpression in mouse and/or nonneuronal systems. We used isogenic euploid human induced pluripotent stem cell lines to generate and study an allelic series of PS1 mutations, including heterozygous null mutations and homozygous and heterozygous FAD PS1 mutations. Rigorous analysis of this allelic series in differentiated, purified neurons allowed us to resolve this controversy and to conclude that FAD PS1 mutations, expressed at normal levels in the appropriate cell type, impair γ-secretase activity but do not disrupt γ-secretase-independent functions of PS1. Thus, FAD PS1 mutations do not act as simple loss of PS1 function but instead dominantly gain an activity toxic to some, but not all, PS1 functions.

  3. Life history and the male mutation bias.

    Science.gov (United States)

    Bartosch-Härlid, Anna; Berlin, Sofia; Smith, Nick G C; Møller, Anders P; Ellegren, Hans

    2003-10-01

    If DNA replication is a major cause of mutation, then those life-history characters, which are expected to affect the number of male germline cell divisions, should also affect the male to female mutation bias (alpha(m)). We tested this hypothesis by comparing several clades of bird species, which show variation both in suitable life-history characters (generation time as measured by age at first breeding and sexual selection as measured by frequency of extrapair paternity) and in alpha(m), which was estimated by comparing Z-linked and W-linked substitution rates in gametologous introns. Alpha(m) differences between clades were found to positively covary with both generation time and sexual selection, as expected if DNA replication causes mutation. The effects of extrapair paternity frequency on alpha(m) suggests that increased levels of sexual selection cause higher mutation rates, which offers an interesting solution to the paradox of the loss of genetic variance associated with strong directional sexual selection. We also used relative rate tests to examine whether the observed differences in alpha(m) between clades were due to differences in W-linked or Z-linked substitution rates. In one case, a significant difference in alpha(m) between two clades was shown to be due to W-linked rates and not Z-linked rates, a result that suggests that mutation rates are not determined by replication alone.

  4. Broadening of cohesinopathies: exome sequencing identifies mutations in ANKRD11 in two patients with Cornelia de Lange-overlapping phenotype.

    Science.gov (United States)

    Parenti, I; Gervasini, C; Pozojevic, J; Graul-Neumann, L; Azzollini, J; Braunholz, D; Watrin, E; Wendt, K S; Cereda, A; Cittaro, D; Gillessen-Kaesbach, G; Lazarevic, D; Mariani, M; Russo, S; Werner, R; Krawitz, P; Larizza, L; Selicorni, A; Kaiser, F J

    2016-01-01

    Cornelia de Lange syndrome (CdLS) and KBG syndrome are two distinct developmental pathologies sharing common features such as intellectual disability, psychomotor delay, and some craniofacial and limb abnormalities. Mutations in one of the five genes NIPBL, SMC1A, SMC3, HDAC8 or RAD21, were identified in at least 70% of the patients with CdLS. Consequently, additional causative genes, either unknown or responsible of partially merging entities, possibly account for the remaining 30% of the patients. In contrast, KBG has only been associated with mutations in ANKRD11. By exome sequencing we could identify heterozygous loss-of-function mutations in ANKRD11 in two patients with the clinical diagnosis of CdLS. Both patients show features reminiscent of CdLS such as characteristic facies as well as a small head circumference which is not described for KBG syndrome. Patient A, who carries the mutation in a mosaic state, is a 4-year-old girl with features reminiscent of CdLS. Patient B, a 15-year-old boy, shows a complex phenotype which resembled CdLS during infancy, but has developed to a more KBG overlapping phenotype during childhood. These findings point out the importance of screening ANKRD11 in young CdLS patients who were found to be negative for mutations in the five known CdLS genes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Steroid sulfatase and filaggrin mutations in a boy with severe ichthyosis, elevated serum IgE level and moyamoya syndrome.

    Science.gov (United States)

    Zhang, Qian; Si, Nuo; Liu, Yaping; Zhang, Dong; Wang, Rong; Zhang, Yan; Wang, Shuo; Liu, Xingju; Deng, Xiaofeng; Ma, Yonggang; Ge, Peicong; Zhao, Jizong; Zhang, Xue

    2017-09-10

    X-linked ichthyosis (XLI) is a relatively common, recessive condition caused by mutations in the steroid sulfatase (STS) gene. Common loss-of-function mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris and predispose individuals to atopic eczema. We report a case of a 6-year-old boy who presented with unusually severe XLI, an increased serum immunoglobulin E level (2120IU/ml) and moyamoya angiopathy. Whole-exome sequencing identified a gross deletion encompassing the STS in Xp22.31 and the p.K4022X FLG mutation. The deletion is at least 1.6Mb in size in the proband, based on real-time quantitative polymerase chain reaction results. No other genetic mutations related to ichthyosis, moyamoya or hyper-immunoglobulin E syndrome were detected. Furthermore, his mother's brothers suffered from mild XLI and only had a deletion encompassing the STS. Additionally, his father and older sister suffered from mild ichthyosis vulgaris and had the p.K4022X FLG mutation. We report the first case of XLI with concurrent moyamoya syndrome. Moreover, an IgE-mediated immune response may have triggered the moyamoya signaling cascade in this patient with ichthyosis. Furthermore, our study strengthens the hypothesis that filaggrin defects can synergize with an STS deficiency to exacerbate the ichthyosis phenotype in an ethnically diverse population. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. An elastin gene mutation producing abnormal tropoelastin and abnormal elastic fibres in a patient with autosomal dominant cutis laxa.

    Science.gov (United States)

    Tassabehji, M; Metcalfe, K; Hurst, J; Ashcroft, G S; Kielty, C; Wilmot, C; Donnai, D; Read, A P; Jones, C J

    1998-06-01

    Elastin is the protein responsible for the characteristic elastic properties of many tissues including the skin, lungs and large blood vessels. Loss-of-function mutations in the elastin gene are known to cause the heart defect supravalvular aortic stenosis (SVAS). We and others have identified deletions, nonsense mutations and splice site mutations in SVAS patients that abolish the function of one elastin gene. We have now identified an elastin mutation in a patient with a completely different phenotype, the rare autosomal dominant condition cutis laxa. A frameshift mutation in exon 32 of the elastin gene is predicted to replace 37 amino acids at the C-terminus of elastin by a novel sequence of 62 amino acids. mRNA and immunoprecipitation studies show that the mutant allele is expressed. Electron microscopy of skin sections shows abnormal branching and fragmentation in the amorphous elastin component, and immunocytochemistry shows reduced elastin deposition in the elastic fibres and fewer microfibrils in the dermis. These findings suggest that the mutant tropoelastin protein is synthesized, secreted and incorporated into the elastic matrix, where it alters the architecture of elastic fibres. Interference with cross-linking would reduce elastic recoil in affected tissues and explain the cutis laxa phenotype.

  7. Atypical femoral fracture in osteoporosis pseudoglioma syndrome associated with two novel compound heterozygous mutations in LRP5.

    Science.gov (United States)

    Alonso, Nerea; Soares, Dinesh C; V McCloskey, Eugene; Summers, Gregory D; Ralston, Stuart H; Gregson, Celia L

    2015-04-01

    Osteoporosis pseudoglioma syndrome (OPPG) is a rare autosomal recessive condition of congenital blindness and severe childhood osteoporosis with skeletal fragility, caused by loss-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. We report the first case of atypical (subtrochanteric) femoral fracture (AFF) in OPPG, occurring in a 38-year-old man within the context of relatively low bone turnover and trabecular osteoporosis on bone histology. We identify two novel LRP5 mutations: R752W is associated with low bone mineral density (BMD), as demonstrated by the heterozygous carriage identified in his 57-year-old mother; however, the combination of this R752W mutation with another novel W79R mutation, causes a severe case of compound heterozygous OPPG. We undertake 3D homology modeling of the four extracellular YWTD β-propeller/EGF-like domains (E1-E4) of LRP5, and show that both novel mutations destabilize the β-propeller domains that are critical for protein and ligand binding to regulate Wnt signaling and osteoblast function. Although AFFs have been reported in other rare bone diseases, this is the first in a genetic condition of primary osteoblast dysfunction. The relatively low bone turnover observed, and knowledge of LRP5 function, implicates impaired bone remodeling in the pathogenesis of AFF. © 2014 American Society for Bone and Mineral Research.

  8. Titanium: light, strong, and white

    Science.gov (United States)

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  9. Mutations in SULT2B1 Cause Autosomal-Recessive Congenital Ichthyosis in Humans.

    Science.gov (United States)

    Heinz, Lisa; Kim, Gwang-Jin; Marrakchi, Slaheddine; Christiansen, Julie; Turki, Hamida; Rauschendorf, Marc-Alexander; Lathrop, Mark; Hausser, Ingrid; Zimmer, Andreas D; Fischer, Judith

    2017-06-01

    Ichthyoses are a clinically and genetically heterogeneous group of genodermatoses associated with abnormal scaling of the skin over the whole body. Mutations in nine genes are known to cause non-syndromic forms of autosomal-recessive congenital ichthyosis (ARCI). However, not all genetic causes for ARCI have been discovered to date. Using whole-exome sequencing (WES) and multigene panel screening, we identified 6 ARCI-affected individuals from three unrelated families with mutations in Sulfotransferase family 2B member 1 (SULT2B1), showing their causative association with ARCI. Cytosolic sulfotransferases form a large family of enzymes that are involved in the synthesis and metabolism of several steroids in humans. We identified four distinct mutations including missense, nonsense, and splice site mutations. We demonstrated the loss of SULT2B1 expression at RNA and protein levels in keratinocytes from individuals with ARCI by functional analyses. Furthermore, we succeeded in reconstructing the morphologic skin alterations in a 3D organotypic tissue culture model with SULT2B1-deficient keratinocytes and fibroblasts. By thin layer chromatography (TLC) of extracts from these organotypic cultures, we could show the absence of cholesterol sulfate, the metabolite of SULT2B1, and an increased level of cholesterol, indicating a disturbed cholesterol metabolism of the skin upon loss-of-function mutation in SULT2B1. In conclusion, our study reveals an essential role for SULT2B1 in the proper development of healthy human skin. Mutation in SULT2B1 leads to an ARCI phenotype via increased proliferation of human keratinocytes, thickening of epithelial layers, and altered epidermal cholesterol metabolism. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  10. Functional Study of Ectodysplasin-A Mutations Causing Non-Syndromic Tooth Agenesis

    Science.gov (United States)

    Liu, Yang; Liu, Haochen; Zhao, Hongshan; Zhang, Guozhong; Snead, Malcolm L.; Han, Dong; Feng, Hailan

    2016-01-01

    Recent studies have demonstrated that ectodysplasin-A (EDA) mutations are associated with non-syndromic tooth agenesis. Indeed, we were the first to report three novel EDA mutations (A259E, R289C and R334H) in sporadic non-syndromic tooth agenesis. We studied the mechanism linking EDA mutations and non-syndromic tooth agenesis in human embryonic kidney 293T cells and mouse ameloblast-derived LS8 cells transfected with mutant isoforms of EDA. The receptor binding capability of the mutant EDA1 protein was impaired in comparison to wild-type EDA1. Although the non-syndromic tooth agenesis-causing EDA1 mutants possessed residual binding capability, the transcriptional activation of the receptor’s downstream target, nuclear factor κB (NF-κB), was compromised. We also analyzed the changes of selected genes in other signaling pathways, such as WNT and BMP, after EDA mutation. We found that non-syndromic tooth agenesis-causing EDA1 mutant proteins upregulate BMP4 (bone morphogenetic protein 4) mRNA expression and downregulate WNT10A and WNT10B (wingless-type MMTV integration site family member 10A and 10B) mRNA expression. Our results indicated that non-syndromic tooth agenesis causing EDA mutations (A259E, R289C and R334H) were loss-of-function, and suggested that EDA may regulate the expression of WNT10A, WNT10B and BMP4 via NF-κB during tooth development. The results from our study may help to understand the molecular mechanism linking specific EDA mutations with non-syndromic tooth agenesis. PMID:27144394

  11. Mitochondrial impairment observed in fibroblasts from South African Parkinson’s disease patients with parkin mutations

    International Nuclear Information System (INIS)

    Merwe, Celia van der; Loos, Ben; Swart, Chrisna; Kinnear, Craig; Henning, Franclo; Merwe, Lize van der; Pillay, Komala; Muller, Nolan; Zaharie, Dan; Engelbrecht, Lize; Carr, Jonathan

    2014-01-01

    Highlights: • Mitochondrial dysfunction observed in patients with parkin-null mutations. • Mitochondrial ATP levels were decreased. • Electron-dense vacuoles were observed in the patients. • Mitochondria from muscle biopsies appeared within normal limits. • One patient did not show these defects possibly due to compensatory mechanisms. - Abstract: Parkinson’s disease (PD), defined as a neurodegenerative disorder, is characterized by the loss of dopaminergic neurons in the substantia nigra in the midbrain. Loss-of-function mutations in the parkin gene are a major cause of autosomal recessive, early-onset PD. Parkin has been implicated in the maintenance of healthy mitochondria, although previous studies show conflicting findings regarding mitochondrial abnormalities in fibroblasts from patients harboring parkin-null mutations. The aim of the present study was to determine whether South African PD patients with parkin mutations exhibit evidence for mitochondrial dysfunction. Fibroblasts were cultured from skin biopsies obtained from three patients with homozygous parkin-null mutations, two heterozygous mutation carriers and two wild-type controls. Muscle biopsies were obtained from two of the patients. The muscle fibers showed subtle abnormalities such as slightly swollen mitochondria in focal areas of the fibers and some folding of the sarcolemma. Although no differences in the degree of mitochondrial network branching were found in the fibroblasts, ultrastructural abnormalities were observed including the presence of electron-dense vacuoles. Moreover, decreased ATP levels which are consistent with mitochondrial dysfunction were observed in the patients’ fibroblasts compared to controls. Remarkably, these defects did not manifest in one patient, which may be due to possible compensatory mechanisms. These results suggest that parkin-null patients exhibit features of mitochondrial dysfunction. Involvement of mitochondria as a key role player in PD

  12. Mitochondrial impairment observed in fibroblasts from South African Parkinson’s disease patients with parkin mutations

    Energy Technology Data Exchange (ETDEWEB)

    Merwe, Celia van der, E-mail: celiavdm@sun.ac.za [Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Loos, Ben [Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch (South Africa); Swart, Chrisna [Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Kinnear, Craig [Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); MRC Centre for Molecular and Cellular Biology and the DST/NRF Centre of Excellence for Biomedical TB Research, Stellenbosch University, Cape Town (South Africa); Henning, Franclo [Division of Neurology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Merwe, Lize van der [Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Department of Statistics, University of the Western Cape, Cape Town (South Africa); Pillay, Komala [National Health Laboratory Services (NHLS) Histopathology Laboratory, Red Cross Children’s Hospital, Cape Town (South Africa); Muller, Nolan [Division of Anatomical Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Zaharie, Dan [Neuropathology Unit, Division of Anatomical Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); Engelbrecht, Lize [Cell Imaging Unit, Central Analytical Facility, Stellenbosch University, Cape Town (South Africa); Carr, Jonathan [Division of Neurology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town (South Africa); and others

    2014-05-02

    Highlights: • Mitochondrial dysfunction observed in patients with parkin-null mutations. • Mitochondrial ATP levels were decreased. • Electron-dense vacuoles were observed in the patients. • Mitochondria from muscle biopsies appeared within normal limits. • One patient did not show these defects possibly due to compensatory mechanisms. - Abstract: Parkinson’s disease (PD), defined as a neurodegenerative disorder, is characterized by the loss of dopaminergic neurons in the substantia nigra in the midbrain. Loss-of-function mutations in the parkin gene are a major cause of autosomal recessive, early-onset PD. Parkin has been implicated in the maintenance of healthy mitochondria, although previous studies show conflicting findings regarding mitochondrial abnormalities in fibroblasts from patients harboring parkin-null mutations. The aim of the present study was to determine whether South African PD patients with parkin mutations exhibit evidence for mitochondrial dysfunction. Fibroblasts were cultured from skin biopsies obtained from three patients with homozygous parkin-null mutations, two heterozygous mutation carriers and two wild-type controls. Muscle biopsies were obtained from two of the patients. The muscle fibers showed subtle abnormalities such as slightly swollen mitochondria in focal areas of the fibers and some folding of the sarcolemma. Although no differences in the degree of mitochondrial network branching were found in the fibroblasts, ultrastructural abnormalities were observed including the presence of electron-dense vacuoles. Moreover, decreased ATP levels which are consistent with mitochondrial dysfunction were observed in the patients’ fibroblasts compared to controls. Remarkably, these defects did not manifest in one patient, which may be due to possible compensatory mechanisms. These results suggest that parkin-null patients exhibit features of mitochondrial dysfunction. Involvement of mitochondria as a key role player in PD

  13. Exome Sequencing Reveals Mutations in AIRE as a Cause of Isolated Hypoparathyroidism.

    Science.gov (United States)

    Li, Dong; Streeten, Elizabeth A; Chan, Alice; Lwin, Wint; Tian, Lifeng; Pellegrino da Silva, Renata; Kim, Cecilia E; Anderson, Mark S; Hakonarson, Hakon; Levine, Michael A

    2017-05-01

    Most cases of autosomal recessive hypoparathyroidism (HYPO) are caused by loss-of-function mutations in GCM2 or PTH. The objective of this study was to identify the underlying genetic basis for isolated HYPO in a kindred in which 3 of 10 siblings were affected. We studied the parents and the three adult affected subjects, each of whom was diagnosed with HYPO in the first decade of life. We collected clinical and biochemical data and performed whole exome sequencing analysis on DNA from the three affected subjects after negative genetic testing for known causes of HYPO. Whole exome sequencing followed by Sanger sequencing revealed that all three affected subjects were compound heterozygous for two previously reported mutations, c.967_979delCTGTCCCCTCCGC:p.(L323SfsX51) and c.995+(3_5)delGAGinsTAT, in AIRE, which encodes the autoimmune regulator protein that is defective in autoimmune polyglandular syndrome type 1 (APS-1). Each parent carries one mutation, and all of the children of the patients are either heterozygous for one mutation or wild type. The affected sister developed premature ovarian failure, but the two affected brothers have no other features of APS-1 despite elevated serum levels of anti-interferon-α antibodies. Our findings indicate that biallelic mutations in AIRE can cause isolated HYPO as well as syndromic APS-1. The presence of antibodies to interferon-α provides a highly sensitive indicator for loss of AIRE function and represents a useful marker for isolated HYPO due to AIRE mutations. Copyright © 2017 Endocrine Society

  14. Germline mutations of TP53 gene in breast cancer.

    Science.gov (United States)

    Damineni, Surekha; Rao, Vadlamudi Raghavendra; Kumar, Satish; Ravuri, Rajasekar Reddy; Kagitha, Sailaja; Dunna, Nageswara Rao; Digumarthi, Raghunadharao; Satti, Vishnupriya

    2014-09-01

    Germline alterations of the TP53 gene encoding the p53 protein have been observed in the majority of families with the Li-Fraumeni syndrome, a rare dominantly inherited disorder with breast cancer. Genomic DNA samples of 182 breast cancer cases and 186 controls were sequenced for TP53 mutations in the exon 5-9 and intervening introns 5, 7-9. Direct sequencing was done using Applied Biosystem 3730 DNA analyzer. In the present study, we observed nine mutations in the sequenced region, of which five were novel. Hardy-Weinberg equilibrium (HWE) was done for all the mutations; C14181T, T14201G, and G13203A have shown deviation from HWE. High linkage disequilibrium (LD) was observed between C14181T (rs129547788) and T14201G (rs12951053) (r (2) = 0.98.3; D' = 1.00), whereas other observed mutations do not show strong LD with any of the other mutations. None of the intronic mutations has shown significant association with the breast cancer, two exonic mutations G13203A (rs28934578) and A14572G are significantly (P = 0.04, P = 0.007) associated with breast cancer. Germline mutations observed in DNA-binding domain of the gene showed significant association with breast cancer. This study reports five novel germline mutations in the TP53 gene out of which one mutation may confer significant risk to the breast cancer. Mutations in DNA-binding domain of TP53 gene may play role in the early onset and prognosis of breast cancer. The population-based studies of germline mutations in DNA-binding domain of TP53 gene helps in identification of individuals and families who are at risk of developing cancers.

  15. TERT promoter mutations are frequent and show association with MED12 mutations in phyllodes tumors of the breast

    Science.gov (United States)

    Yoshida, Masayuki; Ogawa, Reiko; Yoshida, Hiroshi; Maeshima, Akiko; Kanai, Yae; Kinoshita, Takayuki; Hiraoka, Nobuyoshi; Sekine, Shigeki

    2015-01-01

    Background: Phyllodes tumors are rare fibroepithelial neoplasms of the breast, which carry the potential risk of local recurrence and metastasis. Phyllodes tumors share several histological features with fibroadenomas, and no widely accepted markers for distinguishing these lesions have been identified. Methods: We analyzed molecular abnormalities related to telomere elongation in tumors, including TERT promoter mutations, as well as loss of expression of ATRX and DAXX, in a total of 104 phyllodes tumors and fibroadenomas. Results: Sequencing analyses showed that TERT promoter mutations were frequent in phyllodes tumors (30/46, 65%), but rare in fibroadenomas (4/58, 7%). Among phyllodes tumors, the mutations were more frequent in borderline tumors (13/15, 87%), but were also common in benign (9/18, 50%) and malignant tumors (8/13, 62%). Remarkably, all but one TERT promoter-mutated tumor also contained MED12 mutations, indicating that these mutations are strongly associated (P=8.4 × 10−6). Expression of ATRX and DAXX, as evaluated by immunohistochemistry, was retained in all tumors. Conclusions: Our observations suggest a critical role of TERT promoter mutations, in cooperation with MED12 mutations, in the development of phyllodes tumors. Because TERT promoter mutations are rare among fibroadenomas, their detection may be of potential use in discriminating between phyllodes tumors and fibroadenomas. PMID:26355235

  16. Mutational spectrum drives the rise of mutator bacteria.

    Science.gov (United States)

    Couce, Alejandro; Guelfo, Javier R; Blázquez, Jesús

    2013-01-01

    Understanding how mutator strains emerge in bacterial populations is relevant both to evolutionary theory and to reduce the threat they pose in clinical settings. The rise of mutator alleles is understood as a result of their hitchhiking with linked beneficial mutations, although the factors that govern this process remain unclear. A prominent but underappreciated fact is that each mutator allele increases only a specific spectrum of mutational changes. This spectrum has been speculated to alter the distribution of fitness effects of beneficial mutations, potentially affecting hitchhiking. To study this possibility, we analyzed the fitness distribution of beneficial mutations generated from different mutator and wild-type Escherichia coli strains. Using antibiotic resistance as a model system, we show that mutational spectra can alter these distributions substantially, ultimately determining the competitive ability of each strain across environments. Computer simulation showed that the effect of mutational spectrum on hitchhiking dynamics follows a non-linear function, implying that even slight spectrum-dependent fitness differences are sufficient to alter mutator success frequency by several orders of magnitude. These results indicate an unanticipated central role for the mutational spectrum in the evolution of bacterial mutation rates. At a practical level, this study indicates that knowledge of the molecular details of resistance determinants is crucial for minimizing mutator evolution during antibiotic therapy.

  17. Mutational spectrum drives the rise of mutator bacteria.

    Directory of Open Access Journals (Sweden)

    Alejandro Couce

    Full Text Available Understanding how mutator strains emerge in bacterial populations is relevant both to evolutionary theory and to reduce the threat they pose in clinical settings. The rise of mutator alleles is understood as a result of their hitchhiking with linked beneficial mutations, although the factors that govern this process remain unclear. A prominent but underappreciated fact is that each mutator allele increases only a specific spectrum of mutational changes. This spectrum has been speculated to alter the distribution of fitness effects of beneficial mutations, potentially affecting hitchhiking. To study this possibility, we analyzed the fitness distribution of beneficial mutations generated from different mutator and wild-type Escherichia coli strains. Using antibiotic resistance as a model system, we show that mutational spectra can alter these distributions substantially, ultimately determining the competitive ability of each strain across environments. Computer simulation showed that the effect of mutational spectrum on hitchhiking dynamics follows a non-linear function, implying that even slight spectrum-dependent fitness differences are sufficient to alter mutator success frequency by several orders of magnitude. These results indicate an unanticipated central role for the mutational spectrum in the evolution of bacterial mutation rates. At a practical level, this study indicates that knowledge of the molecular details of resistance determinants is crucial for minimizing mutator evolution during antibiotic therapy.

  18. Mutations in connexin 32: the molecular and biophysical bases for the X-linked form of Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Abrams, C K; Oh, S; Ri, Y; Bargiello, T A

    2000-04-01

    The connexins are a family of homologous integral membrane proteins that form channels that provide a low resistance pathway for the transmission of electrical signals and the diffusion of small ions and non-electrolytes between coupled cells. Individuals carrying mutations in the gene encoding connexin 32 (Cx32), a gap junction protein expressed in the paranodal loops and Schmidt-Lantermann incisures of myelinating Schwann cells, develop a peripheral neuropathy - the X-linked form of Charcot-Marie-Tooth disease (CMTX). Over 160 different mutations in Cx32 associated with CMTX have been identified. Some mutations will lead to complete loss of function with no possibility of expression of functional channels. Some mutations in Cx32 lead to the abnormal accumulation of Cx32 proteins in the cytoplasm, particularly in the Golgi apparatus; CMTX may arise due to incorrect trafficking of Cx32 or to interference with trafficking of other proteins. On the other hand, many mutant forms of Cx32 can form functional channels. Some functional mutants have conductance voltage relationships that are disrupted to a degree which would lead to a substantial reduction in the available gap junction mediated communication pathway. Others have essentially normal steady-state g-V relations. In one of these cases (Ser26Leu), the only change introduced by the mutation is a reduction in the pore diameter from 7 A for the wild-type channel to less than 3 A for Ser26Leu. This reduction in pore diameter may restrict the passage of important signaling molecules. These findings suggest that in some, if not all cases of CMTX, loss of function of normal Cx32 is sufficient to cause CMTX.

  19. Deletions and de novo mutations of SOX11 are associated with a neurodevelopmental disorder with features of Coffin-Siris syndrome.

    Science.gov (United States)

    Hempel, Annmarie; Pagnamenta, Alistair T; Blyth, Moira; Mansour, Sahar; McConnell, Vivienne; Kou, Ikuyo; Ikegawa, Shiro; Tsurusaki, Yoshinori; Matsumoto, Naomichi; Lo-Castro, Adriana; Plessis, Ghislaine; Albrecht, Beate; Battaglia, Agatino; Taylor, Jenny C; Howard, Malcolm F; Keays, David; Sohal, Aman Singh; Kühl, Susanne J; Kini, Usha; McNeill, Alisdair

    2016-03-01

    SOX11 is a transcription factor proposed to play a role in brain development. The relevance of SOX11 to human developmental disorders was suggested by a recent report of SOX11 mutations in two patients with Coffin-Siris syndrome. Here we further investigate the role of SOX11 variants in neurodevelopmental disorders. We used array based comparative genomic hybridisation and trio exome sequencing to identify children with intellectual disability who have deletions or de novo point mutations disrupting SOX11. The pathogenicity of the SOX11 mutations was assessed using an in vitro gene expression reporter system. Loss-of-function experiments were performed in xenopus by knockdown of Sox11 expression. We identified seven individuals with chromosome 2p25 deletions involving SOX11. Trio exome sequencing identified three de novo SOX11 variants, two missense (p.K50N; p.P120H) and one nonsense (p.C29*). The biological consequences of the missense mutations were assessed using an in vitro gene expression system. These individuals had microcephaly, developmental delay and shared dysmorphic features compatible with mild Coffin-Siris syndrome. To further investigate the function of SOX11, we knocked down the orthologous gene in xenopus. Morphants had significant reduction in head size compared with controls. This suggests that SOX11 loss of function can be associated with microcephaly. We thus propose that SOX11 deletion or mutation can present with a Coffin-Siris phenotype. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Protein Structure-Function Relationship at Work: Learning from Myopathy Mutations of the Slow Skeletal Muscle Isoform of Troponin T.

    Science.gov (United States)

    Mondal, Anupom; Jin, J-P

    2016-01-01

    Troponin T (TnT) is the sarcomeric thin filament anchoring subunit of the troponin complex in striated muscles. A nonsense mutation in exon 11 of the slow skeletal muscle isoform of TnT (ssTnT) gene ( TNNT1 ) was found in the Amish populations in Pennsylvania and Ohio. This single nucleotide substitution causes a truncation of the ssTnT protein at Glu 180 and the loss of the C-terminal tropomyosin (Tm)-binding site 2. As a consequence, it abolishes the myofilament integration of ssTnT and the loss of function causes an autosomal recessive nemaline myopathy (NM). More TNNT1 mutations have recently been reported in non-Amish ethnic groups with similar recessive NM phenotypes. A nonsense mutation in exon 9 truncates ssTnT at Ser 108 , deleting Tm-binding site 2 and a part of the middle region Tm-binding site 1. Two splicing site mutations result in truncation of ssTnT at Leu 203 or deletion of the exon 14-encoded C-terminal end segment. Another splicing mutation causes an internal deletion of the 39 amino acids encoded by exon 8, partially damaging Tm-binding site 1. The three splicing mutations of TNNT1 all preserve the high affinity Tm-binding site 2 but still present recessive NM phenotypes. The molecular mechanisms for these mutations to cause myopathy provide interesting models to study and understand the structure-function relationship of TnT. This focused review summarizes the current knowledge of TnT isoform regulation, structure-function relationship of TnT and how various ssTnT mutations cause recessive NM, in order to promote in depth studies for further understanding the pathogenesis and pathophysiology of TNNT1 myopathies toward the development of effective treatments.

  1. Detecting clusters of mutations.

    Directory of Open Access Journals (Sweden)

    Tong Zhou

    Full Text Available Positive selection for protein function can lead to multiple mutations within a small stretch of DNA, i.e., to a cluster of mutations. Recently, Wagner proposed a method to detect such mutation clusters. His method, however, did not take into account that residues with high solvent accessibility are inherently more variable than residues with low solvent accessibility. Here, we propose a new algorithm to detect clustered evolution. Our algorithm controls for different substitution probabilities at buried and exposed sites in the tertiary protein structure, and uses random permutations to calculate accurate P values for inferred clusters. We apply the algorithm to genomes of bacteria, fly, and mammals, and find several clusters of mutations in functionally important regions of proteins. Surprisingly, clustered evolution is a relatively rare phenomenon. Only between 2% and 10% of the genes we analyze contain a statistically significant mutation cluster. We also find that not controlling for solvent accessibility leads to an excess of clusters in terminal and solvent-exposed regions of proteins. Our algorithm provides a novel method to identify functionally relevant divergence between groups of species. Moreover, it could also be useful to detect artifacts in automatically assembled genomes.

  2. Mutations in MDH2, Encoding a Krebs Cycle Enzyme, Cause Early-Onset Severe Encephalopathy.

    Science.gov (United States)

    Ait-El-Mkadem, Samira; Dayem-Quere, Manal; Gusic, Mirjana; Chaussenot, Annabelle; Bannwarth, Sylvie; François, Bérengère; Genin, Emmanuelle C; Fragaki, Konstantina; Volker-Touw, Catharina L M; Vasnier, Christelle; Serre, Valérie; van Gassen, Koen L I; Lespinasse, Françoise; Richter, Susan; Eisenhofer, Graeme; Rouzier, Cécile; Mochel, Fanny; De Saint-Martin, Anne; Abi Warde, Marie-Thérèse; de Sain-van der Velde, Monique G M; Jans, Judith J M; Amiel, Jeanne; Avsec, Ziga; Mertes, Christian; Haack, Tobias B; Strom, Tim; Meitinger, Thomas; Bonnen, Penelope E; Taylor, Robert W; Gagneur, Julien; van Hasselt, Peter M; Rötig, Agnès; Delahodde, Agnès; Prokisch, Holger; Fuchs, Sabine A; Paquis-Flucklinger, Véronique

    2017-01-05

    MDH2 encodes mitochondrial malate dehydrogenase (MDH), which is essential for the conversion of malate to oxaloacetate as part of the proper functioning of the Krebs cycle. We report bi-allelic pathogenic mutations in MDH2 in three unrelated subjects presenting with early-onset generalized hypotonia, psychomotor delay, refractory epilepsy, and elevated lactate in the blood and cerebrospinal fluid. Functional studies in fibroblasts from affected subjects showed both an apparently complete loss of MDH2 levels and MDH2 enzymatic activity close to null. Metabolomics analyses demonstrated a significant concomitant accumulation of the MDH substrate, malate, and fumarate, its immediate precursor in the Krebs cycle, in affected subjects' fibroblasts. Lentiviral complementation with wild-type MDH2 cDNA restored MDH2 levels and mitochondrial MDH activity. Additionally, introduction of the three missense mutations from the affected subjects into Saccharomyces cerevisiae provided functional evidence to support their pathogenicity. Disruption of the Krebs cycle is a hallmark of cancer, and MDH2 has been recently identified as a novel pheochromocytoma and paraganglioma susceptibility gene. We show that loss-of-function mutations in MDH2 are also associated with severe neurological clinical presentations in children. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Nonsense Mutation Inside Anthocyanidin Synthase Gene Controls Pigmentation in Yellow Raspberry (Rubus idaeus L.).

    Science.gov (United States)

    Rafique, Muhammad Z; Carvalho, Elisabete; Stracke, Ralf; Palmieri, Luisa; Herrera, Lorena; Feller, Antje; Malnoy, Mickael; Martens, Stefan

    2016-01-01

    Yellow raspberry fruits have reduced anthocyanin contents and offer unique possibility to study the genetics of pigment biosynthesis in this important soft fruit. Anthocyanidin synthase ( Ans ) catalyzes the conversion of leucoanthocyanidin to anthocyanidin, a key committed step in biosynthesis of anthocyanins. Molecular analysis of the Ans gene enabled to identify an inactive ans allele in a yellow fruit raspberry ("Anne"). A 5 bp insertion in the coding region was identified and designated as ans +5 . The insertion creates a premature stop codon resulting in a truncated protein of 264 amino acids, compared to 414 amino acids wild-type ANS protein. This mutation leads to loss of function of the encoded protein that might also result in transcriptional downregulation of Ans gene as a secondary effect, i.e., nonsense-mediated mRNA decay. Further, this mutation results in loss of visible and detectable anthocyanin pigments. Functional characterization of raspberry Ans / ans alleles via complementation experiments in the Arabidopsis thaliana ldox mutant supports the inactivity of encoded protein through ans +5 and explains the proposed block in the anthocyanin biosynthetic pathway in raspberry. Taken together, our data shows that the mutation inside Ans gene in raspberry is responsible for yellow fruit phenotypes.

  4. Nonsense mutation inside anthocyanidin synthase gene controls pigmentation in yellow raspberry (Rubus idaeus L..

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Rafique

    2016-12-01

    Full Text Available Yellow raspberry fruits have reduced anthocyanin contents and offer unique possibility to study the genetics of pigment biosynthesis in this important soft fruit. Anthocyanidin synthase catalyzes the conversion of leucoanthocyanidin to anthocyanidin, a key committed step in biosynthesis of anthocyanins. Molecular analysis of the Ans gene enabled to identify an inactive ans allele in a yellow fruit raspberry (Anne. A 5-bp insertion in the coding region was identified and designated as ans+5. The insertion creates a premature stop codon resulting in a truncated protein of 264 amino acids, compared to 414 amino acids wild type ANS protein. This mutation leads to loss of function of the encoded protein that might also result in transcriptional downregulation of Ans gene as a secondary effect i.e. nonsense-mRNA mediated decay. Further, this mutation results in loss of visible and detectable anthocyanin pigments. Functional characterization of raspberry Ans/ans alleles via complementation experiments in the Arabidopsis thaliana ldox mutant supports the inactivity of encoded protein through ans+5 and explains the proposed block in the anthocyanin biosynthetic pathway in raspberry. Taken together, our data shows that the mutation inside Ans gene in raspberry is responsible for yellow fruit phenotypes.

  5. Characterization of N-terminally mutated cardiac Na+ channels associated with long QT syndrome 3 and Brugada syndrome

    Directory of Open Access Journals (Sweden)

    Christian eGütter

    2013-06-01

    Full Text Available Mutations in SCN5A, the gene encoding the cardiac voltage-gated Na+ channel hNav1.5, can result in life-threatening arrhythmias including long QT syndrome 3 (LQT3 and Brugada syndrome (BrS. Numerous mutant hNav1.5 channels have been characterized upon heterologous expression and patch-clamp recordings during the last decade. These studies revealed functionally important regions in hNav1.5 and provided insight into gain-of-function or loss-of-function channel defects underlying LQT3 or BrS, respectively. The N-terminal region of hNav1.5, however, has not yet been investigated in detail, although several mutations were reported in the literature. In the present study we investigated three mutant channels, previously associated with LQT3 (G9V, R18W, V125L, and six mutant channels, associated with BrS (R18Q, R27H, G35S, V95I, R104Q, K126E. We applied both the two-microelectrode voltage clamp technique, using cRNA-injected Xenopus oocytes, and the whole-cell patch clamp technique using transfected HEK293 cells. Surprisingly, four out of the nine mutations did not affect channel properties. Gain-of-function, as typically observed in LQT3 mutant channels, was observed only in R18W and V125L, whereas loss-of-function, frequently found in BrS mutants, was found only in R27H, R104Q, and K126E. Our results indicate that the hNav1.5 N-terminus plays an important role for channel kinetics and stability. At the same time, we suggest that additional mechanisms, as e.g. disturbed interactions of the Na+ channel N-terminus with other proteins, contribute to severe clinical phenotypes.

  6. Brittle cornea syndrome ZNF469 mutation carrier phenotype and segregation analysis of rare ZNF469 variants in familial keratoconus.

    Science.gov (United States)

    Davidson, Alice E; Borasio, Edmondo; Liskova, Petra; Khan, Arif O; Hassan, Hala; Cheetham, Michael E; Plagnol, Vincent; Alkuraya, Fowzan S; Tuft, Stephen J; Hardcastle, Alison J

    2015-01-06

    Brittle cornea syndrome 1 (BCS1) is a rare recessive condition characterized by extreme thinning of the cornea and sclera, caused by mutations in ZNF469. Keratoconus is a relatively common disease characterized by progressive thinning and ectasia of the cornea. The etiology of keratoconus is complex and not yet understood, but rare ZNF469 variants have recently been associated with disease. We investigated the phenotype of BCS1 carriers with known pathogenic ZNF469 mutations, and recruited families in which aggregation of keratoconus was observed to establish if rare variants in ZNF469 segregated with disease. Patients and family members were recruited and underwent comprehensive anterior segment examination, including corneal topography. Blood samples were donated and genomic DNA was extracted. The coding sequence and splice sites of ZNF469 were PCR amplified and Sanger sequenced. Four carriers of three BCS1-associated ZNF469 loss-of-function mutations (p.[Glu1392Ter], p.[Gln1930Argfs*6], p.[Gln1930fs*133]) were examined and none had keratoconus. One carrier had partially penetrant features of BCS1, including joint hypermobility. ZNF469 sequencing in 11 keratoconus families identified 9 rare (minor allele frequency [MAF] ≤ 0.025) variants predicted to be potentially damaging. However, in each instance the rare variant(s) identified, including two previously reported as potentially keratoconus-associated, did not segregate with the disease. The presence of heterozygous loss-of-function alleles in the ZNF469 gene did not cause keratoconus in the individuals examined. None of the rare nonsynonymous ZNF469 variants identified in the familial cohort conferred a high risk of keratoconus; therefore, genetic variants contributing to disease pathogenesis in these 11 families remain to be identified. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  7. The SNAP Strong Lens Survey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, P.

    2005-01-03

    Basic considerations of lens detection and identification indicate that a wide field survey of the types planned for weak lensing and Type Ia SNe with SNAP are close to optimal for the optical detection of strong lenses. Such a ''piggy-back'' survey might be expected even pessimistically to provide a catalogue of a few thousand new strong lenses, with the numbers dominated by systems of faint blue galaxies lensed by foreground ellipticals. After sketching out our strategy for detecting and measuring these galaxy lenses using the SNAP images, we discuss some of the scientific applications of such a large sample of gravitational lenses: in particular we comment on the partition of information between lens structure, the source population properties and cosmology. Understanding this partitioning is key to assessing strong lens cosmography's value as a cosmological probe.

  8. Strong coupling phase in QED

    International Nuclear Information System (INIS)

    Aoki, Ken-ichi

    1988-01-01

    Existence of a strong coupling phase in QED has been suggested in solutions of the Schwinger-Dyson equation and in Monte Carlo simulation of lattice QED. In this article we recapitulate the previous arguments, and formulate the problem in the modern framework of the renormalization theory, Wilsonian renormalization. This scheme of renormalization gives the best understanding of the basic structure of a field theory especially when it has a multi-phase structure. We resolve some misleading arguments in the previous literature. Then we set up a strategy to attack the strong phase, if any. We describe a trial; a coupled Schwinger-Dyson equation. Possible picture of the strong coupling phase QED is presented. (author)

  9. Are There Mutator Polymerases?

    Directory of Open Access Journals (Sweden)

    Miguel Garcia-Diaz

    2003-01-01

    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  10. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder. The ...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  11. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.

    2007-01-01

    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...

  12. Strong interaction at finite temperature

    Indian Academy of Sciences (India)

    Abstract. We review two methods discussed in the literature to determine the effective parameters of strongly interacting particles as they move through a heat bath. The first one is the general method of chiral perturbation theory, which may be readily applied to this problem. The other is the method of thermal QCD sum rules ...

  13. Strong-strong beam-beam simulation on parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Ji

    2004-08-02

    The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders.

  14. Strong-strong beam-beam simulation on parallel computer

    International Nuclear Information System (INIS)

    Qiang, Ji

    2004-01-01

    The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders

  15. Gain-of-function mutations in the ALS8 causative gene VAPB have detrimental effects on neurons and muscles

    Directory of Open Access Journals (Sweden)

    Mario Sanhueza

    2013-12-01

    Amyotrophic Lateral Sclerosis (ALS is a motor neuron degenerative disease characterized by a progressive, and ultimately fatal, muscle paralysis. The human VAMP-Associated Protein B (hVAPB is the causative gene of ALS type 8. Previous studies have shown that a loss-of-function mechanism is responsible for VAPB-induced ALS. Recently, a novel mutation in hVAPB (V234I has been identified but its pathogenic potential has not been assessed. We found that neuronal expression of the V234I mutant allele in Drosophila (DVAP-V260I induces defects in synaptic structure and microtubule architecture that are opposite to those associated with DVAP mutants and transgenic expression of other ALS-linked alleles. Expression of DVAP-V260I also induces aggregate formation, reduced viability, wing postural defects, abnormal locomotion behavior, nuclear abnormalities, neurodegeneration and upregulation of the heat-shock-mediated stress response. Similar, albeit milder, phenotypes are associated with the overexpression of the wild-type protein. These data show that overexpressing the wild-type DVAP is sufficient to induce the disease and that DVAP-V260I is a pathogenic allele with increased wild-type activity. We propose that a combination of gain- and loss-of-function mechanisms is responsible for VAPB-induced ALS.

  16. Gain-of-function mutations in the ALS8 causative gene VAPB have detrimental effects on neurons and muscles.

    Science.gov (United States)

    Sanhueza, Mario; Zechini, Luigi; Gillespie, Trudy; Pennetta, Giuseppa

    2014-01-15

    Amyotrophic Lateral Sclerosis (ALS) is a motor neuron degenerative disease characterized by a progressive, and ultimately fatal, muscle paralysis. The human VAMP-Associated Protein B (hVAPB) is the causative gene of ALS type 8. Previous studies have shown that a loss-of-function mechanism is responsible for VAPB-induced ALS. Recently, a novel mutation in hVAPB (V234I) has been identified but its pathogenic potential has not been assessed. We found that neuronal expression of the V234I mutant allele in Drosophila (DVAP-V260I) induces defects in synaptic structure and microtubule architecture that are opposite to those associated with DVAP mutants and transgenic expression of other ALS-linked alleles. Expression of DVAP-V260I also induces aggregate formation, reduced viability, wing postural defects, abnormal locomotion behavior, nuclear abnormalities, neurodegeneration and upregulation of the heat-shock-mediated stress response. Similar, albeit milder, phenotypes are associated with the overexpression of the wild-type protein. These data show that overexpressing the wild-type DVAP is sufficient to induce the disease and that DVAP-V260I is a pathogenic allele with increased wild-type activity. We propose that a combination of gain- and loss-of-function mechanisms is responsible for VAPB-induced ALS.

  17. Neurofibromin Loss of Function Drives Excessive Grooming in Drosophila

    Directory of Open Access Journals (Sweden)

    Lanikea B. King

    2016-04-01

    Full Text Available Neurofibromatosis I is a common genetic disorder that results in tumor formation, and predisposes individuals to a range of cognitive/behavioral symptoms, including deficits in attention, visuospatial skills, learning, language development, and sleep, and autism spectrum disorder-like traits. The nf1-encoded neurofibromin protein (Nf1 exhibits high conservation, from the common fruit fly, Drosophila melanogaster, to humans. Drosophila provides a powerful platform to investigate the signaling cascades upstream and downstream of Nf1, and the fly model exhibits similar behavioral phenotypes to mammalian models. In order to understand how loss of Nf1 affects motor behavior in flies, we combined traditional activity monitoring with video analysis of grooming behavior. In nf1 mutants, spontaneous grooming was increased up to 7x. This increase in activity was distinct from previously described dopamine-dependent hyperactivity, as dopamine transporter mutants exhibited slightly decreased grooming. Finally, we found that relative grooming frequencies can be compared in standard activity monitors that measure infrared beam breaks, enabling the use of activity monitors as an automated method to screen for grooming phenotypes. Overall, these data suggest that loss of nf1 produces excessive activity that is manifested as increased grooming, providing a platform to dissect the molecular genetics of neurofibromin signaling across neuronal circuits.

  18. Neurofibromin Loss of Function Drives Excessive Grooming in Drosophila.

    Science.gov (United States)

    King, Lanikea B; Koch, Marta; Murphy, Keith R; Velazquez, Yoheilly; Ja, William W; Tomchik, Seth M

    2016-04-07

    Neurofibromatosis I is a common genetic disorder that results in tumor formation, and predisposes individuals to a range of cognitive/behavioral symptoms, including deficits in attention, visuospatial skills, learning, language development, and sleep, and autism spectrum disorder-like traits. The nf1-encoded neurofibromin protein (Nf1) exhibits high conservation, from the common fruit fly, Drosophila melanogaster, to humans. Drosophila provides a powerful platform to investigate the signaling cascades upstream and downstream of Nf1, and the fly model exhibits similar behavioral phenotypes to mammalian models. In order to understand how loss of Nf1 affects motor behavior in flies, we combined traditional activity monitoring with video analysis of grooming behavior. In nf1 mutants, spontaneous grooming was increased up to 7x. This increase in activity was distinct from previously described dopamine-dependent hyperactivity, as dopamine transporter mutants exhibited slightly decreased grooming. Finally, we found that relative grooming frequencies can be compared in standard activity monitors that measure infrared beam breaks, enabling the use of activity monitors as an automated method to screen for grooming phenotypes. Overall, these data suggest that loss of nf1 produces excessive activity that is manifested as increased grooming, providing a platform to dissect the molecular genetics of neurofibromin signaling across neuronal circuits. Copyright © 2016 King et al.

  19. Mutation, somatic mutation and diseases of man

    International Nuclear Information System (INIS)

    Burnet, F.M.

    1976-01-01

    The relevance of the intrinsic mutagenesis for the evolution process, genetic diseases and the process of aging is exemplified. The fundamental reaction is the function of the DNA and the DNA-enzymes like the DNA-polymerases in replication, repair, and transcription. These defects are responsible for the mutation frequency and the genetic drift in the evolution process. They cause genetic diseases like Xeroderma pigmentosum which is described here in detail. The accumulation of structural and functional mistakes leads to diseases of old age, for example to autoimmune diseases and immune suppression. There is a proportionality between the duration of life and the frequency of mistakes in the enzymatic repair system. No possibility of prophylaxis or therapy is seen. Methods for prognosis could be developed. (AJ) [de

  20. A GDF5 point mutation strikes twice--causing BDA1 and SYNS2.

    Directory of Open Access Journals (Sweden)

    Elisa Degenkolbe

    Full Text Available Growth and Differentiation Factor 5 (GDF5 is a secreted growth factor that belongs to the Bone Morphogenetic Protein (BMP family and plays a pivotal role during limb development. GDF5 is a susceptibility gene for osteoarthritis (OA and mutations in GDF5 are associated with a wide variety of skeletal malformations ranging from complex syndromes such as acromesomelic chondrodysplasias to isolated forms of brachydactylies or multiple synostoses syndrome 2 (SYNS2. Here, we report on a family with an autosomal dominant inherited combination of SYNS2 and additional brachydactyly type A1 (BDA1 caused by a single point mutation in GDF5 (p.W414R. Functional studies, including chondrogenesis assays with primary mesenchymal cells, luciferase reporter gene assays and Surface Plasmon Resonance analysis, of the GDF5(W414R variant in comparison to other GDF5 mutations associated with isolated BDA1 (p.R399C or SYNS2 (p.E491K revealed a dual pathomechanism characterized by a gain- and loss-of-function at the same time. On the one hand insensitivity to the main GDF5 antagonist NOGGIN (NOG leads to a GDF5 gain of function and subsequent SYNS2 phenotype. Whereas on the other hand, a reduced signaling activity, specifically via the BMP receptor type IA (BMPR1A, is likely responsible for the BDA1 phenotype. These results demonstrate that one mutation in the overlapping interface of antagonist and receptor binding site in GDF5 can lead to a GDF5 variant with pathophysiological relevance for both, BDA1 and SYNS2 development. Consequently, our study assembles another part of the molecular puzzle of how loss and gain of function mutations in GDF5 affect bone development in hands and feet resulting in specific types of brachydactyly and SYNS2. These novel insights into the biology of GDF5 might also provide further clues on the pathophysiology of OA.

  1. Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer.

    Science.gov (United States)

    Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Ansari Pour, Naser; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M; Yang, Tsun-Po; Adlard, Julian W; Barwell, Julian; Berg, Jonathan; Brady, Angela F; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J; Paterson, Joan; Porteous, Mary; Rogers, Mark T; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A; Caufield, Mark J; Deloukas, Panagiotis; McCarthy, Mark I; Todd, John A; Turnbull, Clare; Reis-Filho, Jorge S; Ashworth, Alan; Antoniou, Antonis C; Lord, Christopher J; Donnelly, Peter; Rahman, Nazneen

    2013-01-17

    Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12 × 10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42 × 10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10 × 10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification.

  2. CNNM2 mutations cause impaired brain development and seizures in patients with hypomagnesemia.

    Directory of Open Access Journals (Sweden)

    Francisco J Arjona

    2014-04-01

    Full Text Available Intellectual disability and seizures are frequently associated with hypomagnesemia and have an important genetic component. However, to find the genetic origin of intellectual disability and seizures often remains challenging because of considerable genetic heterogeneity and clinical variability. In this study, we have identified new mutations in CNNM2 in five families suffering from mental retardation, seizures, and hypomagnesemia. For the first time, a recessive mode of inheritance of CNNM2 mutations was observed. Importantly, patients with recessive CNNM2 mutations suffer from brain malformations and severe intellectual disability. Additionally, three patients with moderate mental disability were shown to carry de novo heterozygous missense mutations in the CNNM2 gene. To elucidate the physiological role of CNNM2 and explain the pathomechanisms of disease, we studied CNNM2 function combining in vitro activity assays and the zebrafish knockdown model system. Using stable Mg(2+ isotopes, we demonstrated that CNNM2 increases cellular Mg2+ uptake in HEK293 cells and that this process occurs through regulation of the Mg(2+-permeable cation channel TRPM7. In contrast, cells expressing mutated CNNM2 proteins did not show increased Mg(2+ uptake. Knockdown of cnnm2 isoforms in zebrafish resulted in disturbed brain development including neurodevelopmental impairments such as increased embryonic spontaneous contractions and weak touch-evoked escape behaviour, and reduced body Mg content, indicative of impaired renal Mg(2+ absorption. These phenotypes were rescued by injection of mammalian wild-type Cnnm2 cRNA, whereas mammalian mutant Cnnm2 cRNA did not improve the zebrafish knockdown phenotypes. We therefore concluded that CNNM2 is fundamental for brain development, neurological functioning and Mg(2+ homeostasis. By establishing the loss-of-function zebrafish model for CNNM2 genetic disease, we provide a unique system for testing therapeutic drugs

  3. Novel IL1RAPL1 mutations associated with intellectual disability impair synaptogenesis

    Science.gov (United States)

    Ramos-Brossier, Mariana; Montani, Caterina; Lebrun, Nicolas; Gritti, Laura; Martin, Christelle; Seminatore-Nole, Christine; Toussaint, Aurelie; Moreno, Sarah; Poirier, Karine; Dorseuil, Olivier; Chelly, Jamel; Hackett, Anna; Gecz, Jozef; Bieth, Eric; Faudet, Anne; Heron, Delphine; Kooy, Frank; Loeys, Bart; Humeau, Yann; Sala, Carlo; Billuart, Pierre

    2015-01-01

    Mutations in interleukin-1 receptor accessory protein like 1 (IL1RAPL1) gene have been associated with non-syndromic intellectual disability and autism spectrum disorder. This protein interacts with synaptic partners like PSD-95 and PTPδ, regulating the formation and function of excitatory synapses. The aim of this work is to characterize the synaptic consequences of three IL1RAPL1 mutations, two novel causing the deletion of exon 6 (Δex6) and one point mutation (C31R), identified in patients with intellectual disability. Using immunofluorescence and electrophysiological recordings we examined the effects of IL1RAPL1 mutants over-expression on synapse formation and function in cultured rodent hippocampal neurons. Δex6 but not C31R mutation leads to IL1RAPL1 protein instability and mislocalization within dendrites. Analysis of different markers of excitatory synapses and sEPSC recording revealed that both mutants fail to induce pre- and post-synaptic differentiation, contrary to WT IL1RAPL1 protein. Cell aggregation and immunoprecipitation assays in HEK293 cells showed a reduction of the interaction between IL1RAPL1 mutants and PTPδ that could explain the observed synaptogenic defect in neurons. However, these mutants do not affect all cellular signaling since their over-expression still activates JNK pathway. We conclude that both mutations described in this study lead to a partial loss of function of the IL1RAPL1 protein through different mechanisms. Our work highlights the important function of the trans-synaptic PTPδ/ IL1RAPL1 interaction in synaptogenesis and as such, in intellectual disability in the patients. PMID:25305082

  4. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  5. Biological and clinical evidence for somatic mutations in BRCA1 and BRCA2 as predictive markers for olaparib response in high-grade serous ovarian cancers in the maintenance setting.

    Science.gov (United States)

    Dougherty, Brian A; Lai, Zhongwu; Hodgson, Darren R; Orr, Maria C M; Hawryluk, Matthew; Sun, James; Yelensky, Roman; Spencer, Stuart K; Robertson, Jane D; Ho, Tony W; Fielding, Anitra; Ledermann, Jonathan A; Barrett, J Carl

    2017-07-04

    To gain a better understanding of the role of somatic mutations in olaparib response, next-generation sequencing (NGS) of BRCA1 and BRCA2 was performed as part of a planned retrospective analysis of tumors from a randomized, double-blind, Phase II trial (Study 19; D0810C00019; NCT00753545) in 265 patients with platinum-sensitive high-grade serous ovarian cancer. BRCA1/2 loss-of-function mutations were found in 55% (114/209) of tumors, were mutually exclusive, and demonstrated high concordance with Sanger-sequenced germline mutations in matched blood samples, confirming the accuracy (97%) of tumor BRCA1/2 NGS testing. Additionally, NGS identified somatic mutations absent from germline testing in 10% (20/209) of the patients. Somatic mutations had >80% biallelic inactivation frequency and were predominantly clonal, suggesting that BRCA1/2 loss occurs early in the development of these cancers. Clinical outcomes between placebo- and olaparib-treated patients with somatic BRCA1/2 mutations were similar to those with germline BRCA1/2 mutations, indicating that patients with somatic BRCA1/2 mutations benefit from treatment with olaparib.

  6. Tc-99m MDP Bone SPECT/CT Findings of a Patient Detected with a New Mutation in LEMD3 Gene: A Case of Osteopoikilosis.

    Science.gov (United States)

    Silov, Güler; Erdoğan, Zeynep; Erdoğan, Murat; Özdal, Ayşegül; Gençer, Hümeyra; Akalın, Tayfun; Karaçavuş, Seyhan

    2018-02-01

    Osteopoikilosis is an inherited condition with autosomal dominant trait resulting in sclerotic foci throughout the skeleton. It has been suggested that loss-of-function mutations of LEMD3 gene located on 12q14.3 result in osetopoikilosis. A bp heterozygote deletion was detected in our patient at the cytosine nucleotide at position 1105 with molecular genetic analysis. Although this mutation has not been previously described, it was considered to be the most likely cause of the disease in our patient due to frame shift and premature stop codon formation. As in our case, three phase bone scintigraphy and whole body imaging did not reflect the true extent of lesion sites and lesion activity. SPECT/CT images could reflect lesion location and activity more accurately, and could be a good alternative for differential diagnosis of unexplained bone pain and sclerotic lesions in one examination.

  7. Mutation breeding newsletter. No. 33

    International Nuclear Information System (INIS)

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects

  8. Mutation breeding newsletter. No. 45

    International Nuclear Information System (INIS)

    2001-07-01

    This issue of the Mutation Breeding newsletter contains 39 articles dealing with radiation induced mutations and chemical mutagenesis techniques in plant breeding programs with the aims of improving crop productivity and disease resistance as well as exploring genetic variabilities

  9. Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect

    Directory of Open Access Journals (Sweden)

    Wakako Jo

    2010-01-01

    Full Text Available Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD. Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although 123I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

  10. GnRH receptor gene mutations in adolescents and young adults presenting with signs of partial gonadotropin deficiency.

    Directory of Open Access Journals (Sweden)

    Johanna Hietamäki

    Full Text Available Biallelic, partial loss-of-function mutations in GNRHR cause a wide spectrum of reproductive phenotypes from constitutional delay of growth and puberty to complete congenital hypogonadotropic hypogonadism. We studied the frequency of GNRHR, FGFR1, TAC3, and TACR3 mutations in nine adolescent and young adult females with clinical cues consistent with partial gonadotropin deficiency (stalled puberty, unexplained secondary amenorrhea, and describe phenotypic features and molecular genetic findings of monozygotic twin brothers with stalled puberty. Two girls out of nine (22%, 95%CI 6-55% carried biallelic mutations in GNRHR. The girl with compound heterozygous c.317A>G p.(Gln106Arg and c.924_926delCTT p.(Phe309del GNRHR mutations displayed incomplete puberty and clinical signs of hypoestrogenism. The patient carrying a homozygous c.785G>A p.(Arg262Gln mutation presented with signs of hypoestrogenism and unexplained secondary amenorrhea. None of the patients exhibited mutations in FGFR1, TAC3, or TACR3. The twin brothers, compound heterozygous for GNRHR mutations c.317A>G p.(Gln106Arg and c.785G>A p.(Arg262Gln, presented with stalled puberty and were discordant for weight, and the heavier of them had lower testosterone levels. These results suggest that genetic testing of the GNRHR gene should be offered to adolescent females with low-normal gonadotropins and unexplained stalled puberty or menstrual dysfunction. In male patients with partial gonadotropin deficiency, excess adipose tissue may suppress hypothalamic-pituitary-gonadal axis.

  11. Measurement of plasma, serum, and platelet serotonin in individuals with high bone mass and mutations in LRP5.

    Science.gov (United States)

    Lee, Grace S; Simpson, Christine; Sun, Ben-Hua; Yao, Chen; Foer, Dinah; Sullivan, Becky; Matthes, Susann; Alenina, Natalia; Belsky, Joseph; Bader, Michael; Insogna, Karl L

    2014-04-01

    It has recently been suggested that the low-density lipoprotein receptor-related protein 5 (LRP5) regulates bone mass by suppressing secretion of serotonin from duodenal enterochromaffin cells. In mice with targeted expression of a high bone mass-causing (HBM-causing) LRP5 mutation and in humans with HBM LRP5 mutations, circulating serotonin levels have been reported to be lower than in controls whereas individuals with loss-of-function mutations in LRP5 have high blood serotonin. In contrast, others have reported that conditionally activating a knock-in allele of an HBM-causing LRP5 mutation in several tissues, or genetic deletion of LRP5 in mice has no effect on serum serotonin levels. To further explore the possible association between HBM-causing LRP5 mutations and circulating serotonin, levels of the hormone were measured in the platelet poor plasma (PPP), serum, and platelet pellet (PP) of 16 affected individuals from 2 kindreds with HBM-causing LRP5 mutations (G171V and N198S) and 16 age-matched controls. When analyzed by HPLC, there were no differences in levels of serotonin in PPP and PP between affected individuals and age-matched controls. Similarly, when analyzed by ELISA, there were no differences in PPP or PP between these two groups. By ELISA, serum levels of serotonin were higher in the affected individuals when compared to age-matched controls. A subgroup analysis of only the G171V subjects (n=14) demonstrated that there were no differences in PPP and PP serotonin between affected individuals and controls when analyzed by HPLC. PP serotonin was lower in the affected individuals when measured by ELISA but serum serotonin levels were not different. We conclude that there is no change in PPP serotonin in individuals with HBM-causing mutations in LRP5. © 2014 American Society for Bone and Mineral Research.

  12. Strongly correlated systems experimental techniques

    CERN Document Server

    Mancini, Ferdinando

    2015-01-01

    The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

  13. Strongly Correlated Systems Theoretical Methods

    CERN Document Server

    Avella, Adolfo

    2012-01-01

    The volume presents, for the very first time, an exhaustive collection of those modern theoretical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciates consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as po...

  14. Strongly correlated systems numerical methods

    CERN Document Server

    Mancini, Ferdinando

    2013-01-01

    This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possi...

  15. Strongly nonlinear oscillators analytical solutions

    CERN Document Server

    Cveticanin, Livija

    2014-01-01

    This book provides the presentation of the motion of pure nonlinear oscillatory systems and various solution procedures which give the approximate solutions of the strong nonlinear oscillator equations. The book presents the original author’s method for the analytical solution procedure of the pure nonlinear oscillator system. After an introduction, the physical explanation of the pure nonlinearity and of the pure nonlinear oscillator is given. The analytical solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter is considered. Special attention is given to the one and two mass oscillatory systems with two-degrees-of-freedom. The criteria for the deterministic chaos in ideal and non-ideal pure nonlinear oscillators are derived analytically. The method for suppressing chaos is developed. Important problems are discussed in didactic exercises. The book is self-consistent and suitable as a textbook for students and also for profess...

  16. Flavour Democracy in Strong Unification

    CERN Document Server

    Abel, S A; Abel, Steven; King, Steven

    1998-01-01

    We show that the fermion mass spectrum may naturally be understood in terms of flavour democratic fixed points in supersymmetric theories which have a large domain of attraction in the presence of "strong unification". Our approach provides an alternative to the approximate Yukawa texture zeroes of the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken gauged $SU(3)_L\\times SU(3)_R$ family symmetry which illustrates our approach.

  17. Mutations in RAB39B Cause X-Linked Intellectual Disability and Early-Onset Parkinson Disease with α-Synuclein Pathology

    Science.gov (United States)

    Wilson, Gabrielle R.; Sim, Joe C.H.; McLean, Catriona; Giannandrea, Maila; Galea, Charles A.; Riseley, Jessica R.; Stephenson, Sarah E.M.; Fitzpatrick, Elizabeth; Haas, Stefan A.; Pope, Kate; Hogan, Kirk J.; Gregg, Ronald G.; Bromhead, Catherine J.; Wargowski, David S.; Lawrence, Christopher H.; James, Paul A.; Churchyard, Andrew; Gao, Yujing; Phelan, Dean G.; Gillies, Greta; Salce, Nicholas; Stanford, Lynn; Marsh, Ashley P.L.; Mignogna, Maria L.; Hayflick, Susan J.; Leventer, Richard J.; Delatycki, Martin B.; Mellick, George D.; Kalscheuer, Vera M.; D’Adamo, Patrizia; Bahlo, Melanie; Amor, David J.; Lockhart, Paul J.

    2014-01-01

    Advances in understanding the etiology of Parkinson disease have been driven by the identification of causative mutations in families. Genetic analysis of an Australian family with three males displaying clinical features of early-onset parkinsonism and intellectual disability identified a ∼45 kb deletion resulting in the complete loss of RAB39B. We subsequently identified a missense mutation (c.503C>A [p.Thr168Lys]) in RAB39B in an unrelated Wisconsin kindred affected by a similar clinical phenotype. In silico and in vitro studies demonstrated that the mutation destabilized the protein, consistent with loss of function. In vitro small-hairpin-RNA-mediated knockdown of Rab39b resulted in a reduction in the density of α-synuclein immunoreactive puncta in dendritic processes of cultured neurons. In addition, in multiple cell models, we demonstrated that knockdown of Rab39b was associated with reduced steady-state levels of α-synuclein. Post mortem studies demonstrated that loss of RAB39B resulted in pathologically confirmed Parkinson disease. There was extensive dopaminergic neuron loss in the substantia nigra and widespread classic Lewy body pathology. Additional pathological features included cortical Lewy bodies, brain iron accumulation, tau immunoreactivity, and axonal spheroids. Overall, we have shown that loss-of-function mutations in RAB39B cause intellectual disability and pathologically confirmed early-onset Parkinson disease. The loss of RAB39B results in dysregulation of α-synuclein homeostasis and a spectrum of neuropathological features that implicate RAB39B in the pathogenesis of Parkinson disease and potentially other neurodegenerative disorders. PMID:25434005

  18. Direct estimation of the mitochondrial DNA mutation rate in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Cathy Haag-Liautard

    2008-08-01

    Full Text Available Mitochondrial DNA (mtDNA variants are widely used in evolutionary genetics as markers for population history and to estimate divergence times among taxa. Inferences of species history are generally based on phylogenetic comparisons, which assume that molecular evolution is clock-like. Between-species comparisons have also been used to estimate the mutation rate, using sites that are thought to evolve neutrally. We directly estimated the mtDNA mutation rate by scanning the mitochondrial genome of Drosophila melanogaster lines that had undergone approximately 200 generations of spontaneous mutation accumulation (MA. We detected a total of 28 point mutations and eight insertion-deletion (indel mutations, yielding an estimate for the single-nucleotide mutation rate of 6.2 x 10(-8 per site per fly generation. Most mutations were heteroplasmic within a line, and their frequency distribution suggests that the effective number of mitochondrial genomes transmitted per female per generation is about 30. We observed repeated occurrences of some indel mutations, suggesting that indel mutational hotspots are common. Among the point mutations, there is a large excess of G-->A mutations on the major strand (the sense strand for the majority of mitochondrial genes. These mutations tend to occur at nonsynonymous sites of protein-coding genes, and they are expected to be deleterious, so do not become fixed between species. The overall mtDNA mutation rate per base pair per fly generation in Drosophila is estimated to be about 10x higher than the nuclear mutation rate, but the mitochondrial major strand G-->A mutation rate is about 70x higher than the nuclear rate. Silent sites are substantially more strongly biased towards A and T than nonsynonymous sites, consistent with the extreme mutation bias towards A+T. Strand-asymmetric mutation bias, coupled with selection to maintain specific nonsynonymous bases, therefore provides an explanation for the extreme base

  19. Nucleotide selectivity defect and mutator phenotype conferred by a colon cancer-associated DNA polymerase δ mutation in human cells.

    Science.gov (United States)

    Mertz, T M; Baranovskiy, A G; Wang, J; Tahirov, T H; Shcherbakova, P V

    2017-08-01

    Mutations in the POLD1 and POLE genes encoding DNA polymerases δ (Polδ) and ɛ (Polɛ) cause hereditary colorectal cancer (CRC) and have been found in many sporadic colorectal and endometrial tumors. Much attention has been focused on POLE exonuclease domain mutations, which occur frequently in hypermutated DNA mismatch repair (MMR)-proficient tumors and appear to be responsible for the bulk of genomic instability in these tumors. In contrast, somatic POLD1 mutations are seen less frequently and typically occur in MMR-deficient tumors. Their functional significance is often unclear. Here we demonstrate that expression of the cancer-associated POLD1-R689W allele is strongly mutagenic in human cells. The mutation rate increased synergistically when the POLD1-R689W expression was combined with a MMR defect, indicating that the mutator effect of POLD1-R689W results from a high rate of replication errors. Purified human Polδ-R689W has normal exonuclease activity, but the nucleotide selectivity of the enzyme is severely impaired, providing a mechanistic explanation for the increased mutation rate in the POLD1-R689W-expressing cells. The vast majority of mutations induced by the POLD1-R689W are GC→︀TA transversions and GC→︀AT transitions, with transversions showing a strong strand bias and a remarkable preference for polypurine/polypyrimidine sequences. The mutational specificity of the Polδ variant matches that of the hypermutated CRC cell line, HCT15, in which this variant was first identified. The results provide compelling evidence for the pathogenic role of the POLD1-R689W mutation in the development of the human tumor and emphasize the need to experimentally determine the significance of Polδ variants present in sporadic tumors.

  20. Atoms in strong laser fields

    International Nuclear Information System (INIS)

    L'Huillier, A.

    2002-01-01

    When a high-power laser focuses into a gas of atoms, the electromagnetic field becomes of the same magnitude as the Coulomb field which binds a 1s electron in a hydrogen atom. 3 highly non-linear phenomena can happen: 1) ATI (above threshold ionization): electrons initially in the ground state absorb a large number of photons, many more than the minimum number required for ionization; 2) multiple ionization: many electrons can be emitted one at a time, in a sequential process, or simultaneously in a mechanism called direct or non-sequential; and 3) high order harmonic generation (HHG): efficient photon emission in the extreme ultraviolet range, in the form of high-order harmonics of the fundamental laser field can occur. The theoretical problem consists in solving the time dependent Schroedinger equation (TDSE) that describes the interaction of a many-electron atom with a laser field. A number of methods have been proposed to solve this problem in the case of a hydrogen atom or a single-active electron atom in a strong laser field. A large effort is presently being devoted to go beyond the single-active approximation. The understanding of the physics of the interaction between atoms and strong laser fields has been provided by a very simple model called ''simple man's theory''. A unified view of HHG, ATI, and non-sequential ionization, originating from the simple man's model and the strong field approximation, expressed in terms of electrons trajectories or quantum paths is slowly emerging. (A.C.)

  1. Strongly Interacting Light Dark Matter

    Directory of Open Access Journals (Sweden)

    Sebastian Bruggisser, Francesco Riva, Alfredo Urbano

    2017-09-01

    Full Text Available In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM can appear weakly coupled at small energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo Nambu-Goldstone Bosons and Goldstini are interesting targets for LHC missing-energy searches.

  2. Strongly interacting light dark matter

    International Nuclear Information System (INIS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-07-01

    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

  3. Rydberg atoms in strong fields

    International Nuclear Information System (INIS)

    Kleppner, D.; Tsimmerman, M.

    1985-01-01

    Experimental and theoretical achievements in studying Rydberg atoms in external fields are considered. Only static (or quasistatic) fields and ''one-electron'' atoms, i.e. atoms that are well described by one-electron states, are discussed. Mainly behaviour of alkali metal atoms in electric field is considered. The state of theoretical investigations for hydrogen atom in magnetic field is described, but experimental data for atoms of alkali metals are presented as an illustration. Results of the latest experimental and theoretical investigations into the structure of Rydberg atoms in strong fields are presented

  4. Scalar strong interaction hadron theory

    CERN Document Server

    Hoh, Fang Chao

    2015-01-01

    The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.

  5. Strong Plate, Weak Slab Dichotomy

    Science.gov (United States)

    Petersen, R. I.; Stegman, D. R.; Tackley, P.

    2015-12-01

    Models of mantle convection on Earth produce styles of convection that are not observed on Earth.Moreover non-Earth-like modes, such as two-sided downwellings, are the de facto mode of convection in such models.To recreate Earth style subduction, i.e. one-sided asymmetric recycling of the lithosphere, proper treatment of the plates and plate interface are required. Previous work has identified several model features that promote subduction. A free surface or pseudo-free surface and a layer of material with a relatively low strength material (weak crust) allow downgoing plates to bend and slide past overriding without creating undue stress at the plate interface. (Crameri, et al. 2012, GRL)A low viscosity mantle wedge, possibly a result of slab dehydration, decouples the plates in the system. (Gerya et al. 2007, Geo)Plates must be composed of material which, in the case of the overriding plate, are is strong enough to resist bending stresses imposed by the subducting plate and yet, as in the case of the subducting plate, be weak enough to bend and subduct when pulled by the already subducted slab. (Petersen et al. 2015, PEPI) Though strong surface plates are required for subduction such plates may present a problem when they encounter the lower mantle.As the subducting slab approaches the higher viscosity, lower mantle stresses are imposed on the tip.Strong slabs transmit this stress to the surface.There the stress field at the plate interface is modified and potentially modifies the style of convection. In addition to modifying the stress at the plate interface, the strength of the slab affects the morphology of the slab at the base of the upper mantle. (Stegman, et al 2010, Tectonophysics)Slabs that maintain a sufficient portion of their strength after being bent require high stresses to unbend or otherwise change their shape.On the other hand slabs that are weakened though the bending process are more amenable to changes in morphology. We present the results of

  6. Mutation breeding in pepper

    International Nuclear Information System (INIS)

    Daskalov, S.

    1986-01-01

    Pepper (Capsicum sp.) is an important vegetable and spice crop widely grown in tropical as well as in temperate regions. Until recently the improvement programmes were based mainly on using natural sources of germ plasma, crossbreeding and exploiting the heterosis of F 1 hybrids. However, interest in using induced mutations is growing. A great number of agronomically useful mutants as well as mutants valuable for genetic, cytological and physiological studies have been induced and described. In this review information is presented about suitable mutagen treatment procedures with radiation as well as chemicals, M 1 effects, handling the treated material in M 1 , M 2 and subsequent generations, and mutant screening procedures. This is supplemented by a description of reported useful mutants and released cultivars. Finally, general advice is given on when and how to incorporate mutation induction in Capsicum improvement programmes. (author)

  7. Mutations causative of familial hypercholesterolaemia

    DEFF Research Database (Denmark)

    Benn, Marianne; Watts, Gerald F; Tybjærg-Hansen, Anne

    2016-01-01

    causing mutations in 98 098 participants from the general population, the Copenhagen General Population Study. METHODS AND RESULTS: We genotyped for LDLR[W23X;W66G;W556S] and APOB[R3500Q] accounting for 38.7% of pathogenic FH mutations in Copenhagen. Clinical FH assessment excluded mutation information......-cholesterol concentration to discriminate between mutation carriers and non-carriers was 4.4 mmol/L. CONCLUSION: Familial hypercholesterolaemia-causing mutations are estimated to occur in 1:217 in the general population and are best identified by a definite or probable phenotypic diagnosis of FH based on the DLCN criteria...

  8. Mutation selection of strawberries

    International Nuclear Information System (INIS)

    Repka, F.; Tsaganova, I.

    1986-01-01

    A brief account is given of the preliminary results of selection work carried out with the aim of deriving a variety of strawberry suitable for mechanized picking. Mutation selection based on irradiation by gamma rays, fast neutrons and a laser beam has been used. The irradiation was performed on strawberry seedlings grown under field conditions and on in vitro cultures at different stages of development. The studies are continuing. (author)

  9. Novel FGFR1 mutations in Kallmann syndrome and normosmic idiopathic hypogonadotropic hypogonadism: evidence for the involvement of an alternatively spliced isoform.

    Science.gov (United States)

    Gonçalves, Catarina; Bastos, Margarida; Pignatelli, Duarte; Borges, Teresa; Aragüés, José M; Fonseca, Fernando; Pereira, Bernardo D; Socorro, Sílvia; Lemos, Manuel C

    2015-11-01

    To determine the prevalence of fibroblast growth factor receptor 1 (FGFR1) mutations and their predicted functional consequences in patients with idiopathic hypogonadotropic hypogonadism (IHH). Cross-sectional study. Multicentric. Fifty unrelated patients with IHH (21 with Kallmann syndrome and 29 with normosmic IHH). None. Patients were screened for mutations in FGFR1. The functional consequences of mutations were predicted by in silico structural and conservation analysis. Heterozygous FGFR1 mutations were identified in six (12%) kindreds. These consisted of frameshift mutations (p.Pro33-Alafs*17 and p.Tyr654*) and missense mutations in the signal peptide (p.Trp4Cys), in the D1 extracellular domain (p.Ser96Cys) and in the cytoplasmic tyrosine kinase domain (p.Met719Val). A missense mutation was identified in the alternatively spliced exon 8A (p.Ala353Thr) that exclusively affects the D3 extracellular domain of FGFR1 isoform IIIb. Structure-based and sequence-based prediction methods and the absence of these variants in 200 normal controls were all consistent with a critical role for the mutations in the activity of the receptor. Oligogenic inheritance (FGFR1/CHD7/PROKR2) was found in one patient. Two FGFR1 isoforms, IIIb and IIIc, result from alternative splicing of exons 8A and 8B, respectively. Loss-of-function of isoform IIIc is a cause of IHH, whereas isoform IIIb is thought to be redundant. Ours is the first report of normosmic IHH associated with a mutation in the alternatively spliced exon 8A and suggests that this disorder can be caused by defects in either of the two alternatively spliced FGFR1 isoforms. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  10. Septin mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Elias T Spiliotis

    2016-11-01

    Full Text Available Septins are GTP-binding proteins that are evolutionarily and structurally related to the RAS oncogenes. Septin expression levels are altered in many cancers and new advances point to how abnormal septin expression may contribute to the progression of cancer. In contrast to the RAS GTPases, which are frequently mutated and actively promote tumorigenesis, little is known about the occurrence and role of septin mutations in human cancers. Here, we review septin missense mutations that are currently in the Catalog of Somatic Mutations in Cancer (COSMIC database. The majority of septin mutations occur in tumors of the large intestine, skin, endometrium and stomach. Over 25% of the annotated mutations in SEPT2, SEPT4 and SEPT9 belong to large intestine tumors. From all septins, SEPT9 and SEPT14 exhibit the highest mutation frequencies in skin, stomach and large intestine cancers. While septin mutations occur with frequencies lower than 3%, recurring mutations in several invariant and highly conserved amino acids are found across different septin paralogs and tumor types. Interestingly, a significant number of these mutations occur in the GTP-binding pocket and septin dimerization interfaces. Future studies may determine how these somatic mutations affect septin structure and function, whether they contribute to the progression of specific cancers and if they could serve as tumor-specific biomarkers.

  11. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  12. Biallelic mutations in the 3' exonuclease TOE1 cause pontocerebellar hypoplasia and uncover a role in snRNA processing

    DEFF Research Database (Denmark)

    Lardelli, Rea M.; Schaffer, Ashleigh E.; Eggens, Veerle R C

    2017-01-01

    , modeling PCH-like structural defects in vivo. Surprisingly, we found that TOE1 associated with small nuclear RNAs (snRNAs) incompletely processed spliceosomal. These pre-snRNAs contained 3' genome-encoded tails often followed by post-transcriptionally added adenosines. Human cells with reduced levels......Deadenylases are best known for degrading the poly(A) tail during mRNA decay. The deadenylase family has expanded throughout evolution and, in mammals, consists of 12 Mg 2+ -dependent 3'-end RNases with substrate specificity that is mostly unknown. Pontocerebellar hypoplasia type 7 (PCH7......) is a unique recessive syndrome characterized by neurodegeneration and ambiguous genitalia. We studied 12 human families with PCH7, uncovering biallelic, loss-of-function mutations in TOE1, which encodes an unconventional deadenylase. toe1-morphant zebrafish displayed midbrain and hindbrain degeneration...

  13. A Mutator Phenotype Promoting the Emergence of Spontaneous Oxidative Stress-Resistant Mutants in Campylobacter jejuni.

    Science.gov (United States)

    Dai, Lei; Sahin, Orhan; Tang, Yizhi; Zhang, Qijing

    2017-12-15

    Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. As a microaerophilic organism, C. jejuni must be able to defend against oxidative stress encountered both in the host and in the environment. How Campylobacter utilizes a mutation-based mechanism for adaptation to oxidative stress is still unknown. Here we present a previously undescribed phenotypic and genetic mechanism that promotes the emergence of oxidative stress-resistant mutants. Specifically, we showed that a naturally occurring mutator phenotype, resulting from a loss of function mutation in the DNA repair enzyme MutY, increased oxidative stress resistance (OX R ) in C. jejuni We further demonstrated that MutY malfunction did not directly contribute to the OX R phenotype but increased the spontaneous mutation rate in the peroxide regulator gene perR , which functions as a repressor for multiple genes involved in oxidative stress resistance. Mutations in PerR resulted in loss of its DNA binding function and derepression of PerR-controlled oxidative stress defense genes, thereby conferring an OX R phenotype and facilitating Campylobacter survival under oxidative stress. These findings reveal a new mechanism that promotes the emergence of spontaneous OX R mutants in bacterial organisms. IMPORTANCE Although a mutator phenotype has been shown to promote antibiotic resistance in many bacterial species, little is known about its contribution to the emergence of OX R mutants. This work describes the link between a mutator phenotype and the enhanced emergence of OX R mutants as well as its underlying mechanism involving DNA repair and mutations in PerR. Since DNA repair systems and PerR are well conserved in many bacterial species, especially in Gram positives, the same mechanism may operate in multiple bacterial species. Additionally, we developed a novel method that allows for rapid quantification of spontaneous OX R mutants in a bacterial population. This method represents a technical

  14. Mutation induction in spores of Bacillus subtilis by accelerated very heavy ions

    International Nuclear Information System (INIS)

    Baltschukat, K.; Horneck, G.; Buecker, H.; Facius, R.; Schaefer, M.

    1986-01-01

    Mutation induction (resistance to sodium azide) in spores of Bacillus subtilis was investigated after irradiation with heavy ions from Neon to Uranium with specific particle energies between 0.17 and 18.6 MeV/u. A strong dependence of the mutation induction cross section on particle charge and energy was observed. From the results it was concluded that mutation induction in bacterial spores by very heavy ions is mainly caused by secondary electrons. (orig.)

  15. Physics of Strongly Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kraeft, Wolf-Dietrich [Universitat Rostock (Germany)

    2007-07-15

    Strongly coupled plasmas (or non-ideal plasmas) are multi-component charged many-particle systems, in which the mean value of the potential energy of the system is of the same order as or even higher than the mean value of the kinetic energy. The constituents are electrons, ions, atoms and molecules. Dusty (or complex) plasmas contain still mesoscopic (multiply charged) particles. In such systems, the effects of strong coupling (non-ideality) lead to considerable deviations of physical properties from the corresponding properties of ideal plasmas, i.e., of plasmas in which the mean kinetic energy is essentially larger than the mean potential energy. For instance, bound state energies become density dependent and vanish at higher densities (Mott effect) due to the interaction of the pair with the surrounding particles. Non-ideal plasmas are of interest both for general scientific reasons (including, for example, astrophysical questions), and for technical applications such as inertially confined fusion. In spite of great efforts both experimentally and theoretically, satisfactory information on the physical properties of strongly coupled plasmas is not at hand for any temperature and density. For example, the theoretical description of non-ideal plasmas is possible only at low densities/high temperatures and at extremely high densities (high degeneracy). For intermediate degeneracy, however, numerical experiments have to fill the gap. Experiments are difficult in the region of 'warm dense matter'. The monograph tries to present the state of the art concerning both theoretical and experimental attempts. It mainly includes results of the work performed in famous Russian laboratories in recent decades. After outlining basic concepts (chapter 1), the generation of plasmas is considered (chapter 2, chapter 3). Questions of partial (chapter 4) and full ionization (chapter 5) are discussed including Mott transition and Wigner crystallization. Electrical and

  16. Efficient purging of deleterious mutations in plants with haploid selfing

    Energy Technology Data Exchange (ETDEWEB)

    Szovenyi, Peter [Univ. of Zurich (Switzerland); Shaw, Jon [Duke Univ., Durham, NC (United States); Yang, Xiaohan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Devos, Nicolas [Duke Univ., Durham, NC (United States)

    2014-05-30

    In diploid organisms, selfing reduces the efficiency of selection in removing deleterious mutations from a population. This need not be the case for all organisms. Some plants, for example, undergo an extreme form of selfing known as intragametophytic selfing, which immediately exposes all recessive deleterious mutations in a parental genome to selective purging. Here we ask how effectively deleterious mutations are removed from such plants. Specifically, we study the extent to which deleterious mutations accumulate in a predominantly selfing and a predominantly outcrossing pair of moss species, using genome-wide transcriptome data. We find that the selfing species purge significantly more non-synonymous mutations, as well as a greater proportion of radical amino acid changes which alter physicochemical properties of amino acids. Moreover, their purging of deleterious mutation is especially strong in conserved regions of protein-coding genes. Our observations show that selfing need not impede but can even accelerate the removal of deleterious mutations, and do so on a genome-wide scale.

  17. Strongly coupled dust coulomb clusters

    International Nuclear Information System (INIS)

    Juan Wentau; Lai Yingju; Chen Mingheng; I Lin

    1999-01-01

    The structures and motions of quasi-2-dimensional strongly coupled dust Coulomb clusters with particle number N from few to hundreds in a cylindrical rf plasma trap are studied and compared with the results from the molecular dynamic simulation using more ideal models. Shell structures with periodic packing in different shells and intershell rotational motion dominated excitations are observed at small N. As N increases, the boundary has less effect, the system recovers to the triangular lattice with isotropic vortex type cooperative excitations similar to an infinite N system except the outer shell region. The above generic behaviors are mainly determined by the system symmetry and agree with the simulation results. The detailed interaction form causes minor effect such as the fine structure of packing

  18. Probability densities in strong turbulence

    Science.gov (United States)

    Yakhot, Victor

    2006-03-01

    In this work we, using Mellin’s transform combined with the Gaussian large-scale boundary condition, calculate probability densities (PDFs) of velocity increments P(δu,r), velocity derivatives P(u,r) and the PDF of the fluctuating dissipation scales Q(η,Re), where Re is the large-scale Reynolds number. The resulting expressions strongly deviate from the Log-normal PDF P(δu,r) often quoted in the literature. It is shown that the probability density of the small-scale velocity fluctuations includes information about the large (integral) scale dynamics which is responsible for the deviation of P(δu,r) from P(δu,r). An expression for the function D(h) of the multifractal theory, free from spurious logarithms recently discussed in [U. Frisch, M. Martins Afonso, A. Mazzino, V. Yakhot, J. Fluid Mech. 542 (2005) 97] is also obtained.

  19. Homozygous Mutations in WEE2 Cause Fertilization Failure and Female Infertility.

    Science.gov (United States)

    Sang, Qing; Li, Bin; Kuang, Yanping; Wang, Xueqian; Zhang, Zhihua; Chen, Biaobang; Wu, Ling; Lyu, Qifeng; Fu, Yonglun; Yan, Zheng; Mao, Xiaoyan; Xu, Yao; Mu, Jian; Li, Qiaoli; Jin, Li; He, Lin; Wang, Lei

    2018-04-05

    Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when deleted in vivo. In clinical practice, some infertility case subjects suffer from recurrent failure of in vitro fertilization and intracytoplasmic sperm injection attempts due to fertilization failure, but the genetic basis of fertilization failure in humans remains largely unknown. Wee2 is a key oocyte-specific kinase involved in the control of meiotic arrest in mice, but WEE2 has not been associated with any diseases in humans. In this study, we identified homozygous mutations in WEE2 that are responsible for fertilization failure in humans. All four independent affected individuals had homozygous loss-of-function missense mutations or homozygous frameshift protein-truncating mutations, and the phenotype of fertilization failure was shown to follow a Mendelian recessive inheritance pattern. All four mutations significantly decreased the amount of WEE2 protein in vitro and in affected individuals' oocytes in vivo, and they all led to abnormal serine phosphorylation of WEE2 and reduced tyrosine 15 phosphorylation of Cdc2 in vitro. In addition, injection of WEE2 cRNA into affected individuals' oocytes rescued the fertilization failure phenotype and led to the formation of blastocysts in vitro. This work presents a novel gene responsible for human fertilization failure and has implications for future therapeutic treatments for infertility cases. Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  20. TARDBP mutations in amyotrophic lateral sclerosis with TDP-43 neuropathology: a genetic and histopathological analysis.

    Science.gov (United States)

    Van Deerlin, Vivianna M; Leverenz, James B; Bekris, Lynn M; Bird, Thomas D; Yuan, Wuxing; Elman, Lauren B; Clay, Dana; Wood, Elisabeth McCarty; Chen-Plotkin, Alice S; Martinez-Lage, Maria; Steinbart, Ellen; McCluskey, Leo; Grossman, Murray; Neumann, Manuela; Wu, I-Lin; Yang, Wei-Shiung; Kalb, Robert; Galasko, Douglas R; Montine, Thomas J; Trojanowski, John Q; Lee, Virginia M-Y; Schellenberg, Gerard D; Yu, Chang-En

    2008-05-01

    TDP-43 is a major component of the ubiquitinated inclusions that characterise amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitin inclusions (FTLD-U). TDP-43 is an RNA-binding and DNA-binding protein that has many functions and is encoded by the TAR DNA-binding protein gene (TARDBP) on chromosome 1. Our aim was to investigate whether TARDBP is a candidate disease gene for familial ALS that is not associated with mutations in superoxide dismutase 1 (SOD1). TARDBP was sequenced in 259 patients with ALS, FTLD, or both. We used TaqMan-based SNP genotyping to screen for the identified variants in control groups matched to two kindreds of patients for age and ethnic origin. Additional clinical, genetic, and pathological assessments were made in these two families. We identified two variants in TARDBP, which would encode Gly290Ala and Gly298Ser forms of TDP-43, in two kindreds with familial ALS. The variants seem to be pathogenic because they co-segregated with disease in both families, were absent in controls, and were associated with TDP-43 neuropathology in both members of one of these families for whom CNS tissue was available. The Gly290Ala and Gly298Ser mutations are located in the glycine-rich domain of TDP-43, which regulates gene expression and mediates protein-protein interactions such as those with heterogeneous ribonucleoproteins. Owing to the varied and important cellular functions of TDP-43, these mutations might cause neurodegeneration through both gains and losses of function. The finding of pathogenic mutations in TARDBP implicates TDP-43 as an active mediator of neurodegeneration in TDP-43 proteinopathies, a class of disorder that includes ALS and FTLD-U. National Institutes of Health (AG10124, AG17586, AG005136-22, PO1 AG14382), Department of Veterans Affairs, Friedrich-Baur Stiftung (0017/2007), US Public Health Service, ALS Association, and Fundació 'la Caixa'.

  1. Identification of a pathogenic FTO mutation by next-generation sequencing in a newborn with growth retardation and developmental delay.

    Science.gov (United States)

    Daoud, Hussein; Zhang, Dong; McMurray, Fiona; Yu, Andrea; Luco, Stephanie M; Vanstone, Jason; Jarinova, Olga; Carson, Nancy; Wickens, James; Shishodia, Shifali; Choi, Hwanho; McDonough, Michael A; Schofield, Christopher J; Harper, Mary-Ellen; Dyment, David A; Armour, Christine M

    2016-03-01

    A homozygous loss-of-function mutation p.(Arg316Gln) in the fat mass and obesity-associated (FTO) gene, which encodes for an iron and 2-oxoglutarate-dependent oxygenase, was previously identified in a large family in which nine affected individuals present with a lethal syndrome characterised by growth retardation and multiple malformations. To date, no other pathogenic mutation in FTO has been identified as a cause of multiple congenital malformations. We investigated a 21-month-old girl who presented distinctive facial features, failure to thrive, global developmental delay, left ventricular cardiac hypertrophy, reduced vision and bilateral hearing loss. We performed targeted next-generation sequencing of 4813 clinically relevant genes in the patient and her parents. We identified a novel FTO homozygous missense mutation (c.956C>T; p.(Ser319Phe)) in the affected individual. This mutation affects a highly conserved residue located in the same functional domain as the previously characterised mutation p.(Arg316Gln). Biochemical studies reveal that p.(Ser319Phe) FTO has reduced 2-oxoglutarate turnover and N-methyl-nucleoside demethylase activity. Our findings are consistent with previous reports that homozygous mutations in FTO can lead to rare growth retardation and developmental delay syndrome, and further support the proposal that FTO plays an important role in early development of human central nervous and cardiovascular systems. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Hand eczema, atopic dermatitis and filaggrin mutations in adult Danes: a registry-based study assessing risk of disability pension.

    Science.gov (United States)

    Heede, Nina G; Thuesen, Betina H; Thyssen, Jacob P; Linneberg, Allan; Szecsi, Pal B; Stender, Steen; Menné, Torkil; Johansen, Jeanne D

    2017-08-01

    Atopic dermatitis and hand eczema often impair the ability of people to work. Only a few studies have investigated whether individuals with loss-of-function filaggrin gene (FLG) mutations, who often have severe and early onset of dermatitis, experience occupational consequences. To investigate the personal consequences of having atopic dermatitis and/or hand eczema and FLG mutations. Adult Danes from the general population (n = 3247) and patients with atopic dermatitis and/or hand eczema (n = 496) were genotyped for common FLG mutations, and completed a questionnaire about skin symptoms and hand eczema. Socioeconomic variables, including disability pension, and information on work in risk occupations were retrieved from national registries. The reasons for granting disability pension were unknown. Disability pension was associated with hand eczema in the general population, especially among individuals with a history of atopic dermatitis. Moreover, self-reported hand eczema and atopic dermatitis were associated with particularly high risk of disability pension among FLG mutation carriers [odds ratio (OR) 4.02 and 95% confidence interval (CI): 1.15-14.11; and OR 6.01 and 95%CI: 2.37-15.34, respectively]. Furthermore, 60% of the FLG mutation carriers with atopic dermatitis who developed hand eczema had experienced symptoms before adulthood. In the general population, self-reported hand eczema and atopic dermatitis, particularly in individuals with a genetically impaired skin barrier, were associated with disability pension, suggesting that FLG mutations carriers with a history of atopic dermatitis and hand eczema could benefit from early attention with respect to choice of occupation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Mutations in the gene encoding epsilon-sarcoglycan cause myoclonus-dystonia syndrome.

    Science.gov (United States)

    Zimprich, A; Grabowski, M; Asmus, F; Naumann, M; Berg, D; Bertram, M; Scheidtmann, K; Kern, P; Winkelmann, J; Müller-Myhsok, B; Riedel, L; Bauer, M; Müller, T; Castro, M; Meitinger, T; Strom, T M; Gasser, T

    2001-09-01

    The dystonias are a common clinically and genetically heterogeneous group of movement disorders. More than ten loci for inherited forms of dystonia have been mapped, but only three mutated genes have been identified so far. These are DYT1, encoding torsin A and mutant in the early-onset generalized form, GCH1 (formerly known as DYT5), encoding GTP-cyclohydrolase I and mutant in dominant dopa-responsive dystonia, and TH, encoding tyrosine hydroxylase and mutant in the recessive form of the disease. Myoclonus-dystonia syndrome (MDS; DYT11) is an autosomal dominant disorder characterized by bilateral, alcohol-sensitive myoclonic jerks involving mainly the arms and axial muscles. Dystonia, usually torticollis and/or writer's cramp, occurs in most but not all affected patients and may occasionally be the only symptom of the disease. In addition, patients often show prominent psychiatric abnormalities, including panic attacks and obsessive-compulsive behavior. In most MDS families, the disease is linked to a locus on chromosome 7q21 (refs. 11-13). Using a positional cloning approach, we have identified five different heterozygous loss-of-function mutations in the gene for epsilon-sarcoglycan (SGCE), which we mapped to a refined critical region of about 3.2 Mb. SGCE is expressed in all brain regions examined. Pedigree analysis shows a marked difference in penetrance depending on the parental origin of the disease allele. This is indicative of a maternal imprinting mechanism, which has been demonstrated in the mouse epsilon-sarcoglycan gene.

  4. Expanding the clinical and mutational spectrum of the Ehlers-Danlos syndrome, dermatosparaxis type.

    Science.gov (United States)

    Van Damme, Tim; Colige, Alain; Syx, Delfien; Giunta, Cecilia; Lindert, Uschi; Rohrbach, Marianne; Aryani, Omid; Alanay, Yasemin; Simsek-Kiper, Pelin Özlem; Kroes, Hester Y; Devriendt, Koen; Thiry, Marc; Symoens, Sofie; De Paepe, Anne; Malfait, Fransiska

    2016-09-01

    The Ehlers-Danlos syndrome (EDS), dermatosparaxis type, is a recessively inherited connective tissue disorder caused by deficient activity of ADAMTS-2, an enzyme that cleaves the aminoterminal propeptide domain of types I, II, and III procollagen. Only 10 EDS dermatosparaxis patients have been reported, all presenting a recognizable phenotype with characteristic facial gestalt, extreme skin fragility and laxity, excessive bruising, and sometimes major complications due to visceral and vascular fragility. We report on five new EDS dermatosparaxis patients and provide a comprehensive overview of the current knowledge of the natural history of this condition. We identified three novel homozygous loss-of-function mutations (c.2927_2928delCT, p.(Pro976Argfs*42); c.669_670dupG, p.(Pro224Argfs*24); and c.2751-2A>T) and one compound heterozygous mutation (c.2T>C, p.? and c.884_887delTGAA, p.(Met295Thrfs26*)) in ADAMTS2 in five patients from four unrelated families. Three of these displayed a phenotype that was strikingly milder than that of previously reported patients. This study expands the clinical and molecular spectrum of the dermatosparaxis type of EDS to include a milder phenotypic variant and stresses the importance of good clinical criteria. To address this, we propose an updated set of criteria that accurately captures the multisystemic nature of the dermatosparaxis type of EDS.Genet Med 18 9, 882-891.

  5. PRKAR1A mutation causing pituitary-dependent Cushing disease in a patient with Carney complex.

    Science.gov (United States)

    Kiefer, Florian W; Winhofer, Yvonne; Iacovazzo, Donato; Korbonits, Márta; Wolfsberger, Stefan; Knosp, Engelbert; Trautinger, Franz; Höftberger, Romana; Krebs, Michael; Luger, Anton; Gessl, Alois

    2017-08-01

    Carney complex (CNC) is an autosomal dominant condition caused, in most cases, by an inactivating mutation of the PRKAR1A gene, which encodes for the type 1 alpha regulatory subunit of protein kinase A. CNC is characterized by the occurrence of endocrine overactivity, myxomas and typical skin manifestations. Cushing syndrome due to primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine disease observed in CNC. Here, we describe the first case of a patient with CNC and adrenocorticotropic hormone (ACTH)-dependent Cushing disease due to a pituitary corticotroph adenoma. Loss-of-heterozygosity analysis of the pituitary tumour revealed loss of the wild-type copy of PRKAR1A , suggesting a role of this gene in the pituitary adenoma development. PRKAR1A loss-of-function mutations can rarely lead to ACTH-secreting pituitary adenomas in CNC patients. Pituitary-dependent disease should be considered in the differential diagnosis of Cushing syndrome in CNC patients. © 2017 European Society of Endocrinology.

  6. Dysferlinopathy in the Jews of the Caucasus: a frequent mutation in the dysferlin gene.

    Science.gov (United States)

    Leshinsky-Silver, E; Argov, Z; Rozenboim, L; Cohen, S; Tzofi, Z; Cohen, Y; Wirguin, Y; Dabby, R; Lev, D; Sadeh, M

    2007-12-01

    Dysferlin encoding gene (DYS) is mutated in the autosomal recessive disorders Miyoshi myopathy, Limb Girdle Muscular Dystrophy type 2B (LGMD2B) and distal anterior compartment myopathy, causing dysferlin deficiency in muscle biopsy. Three ethnic clusters have previously been described in Dysferlinopathy: the Libyan Jewish population originating in the area of Tripoli, Italian and Spanish populations. We report another cluster of this muscular dystrophy in Israel among Jews of the Caucasus region. A genomic analysis of the dysferlin coding sequence performed in patients from this ethnic group, who demonstrated an absence of dysferlin expression in muscle biopsy, revealed a homozygous frameshift mutation of G deletion at codon 927 (2779delG) predicting a truncated protein and a complete loss of functional protein. The possible existence of a founder effect is strengthened by our finding of a 4% carrier frequency in this community. These findings are important for genetic counseling and also enable a molecular diagnosis of LGMD2B in Jews of the Caucasus region.

  7. ARCN1 Mutations Cause a Recognizable Craniofacial Syndrome Due to COPI-Mediated Transport Defects.

    Science.gov (United States)

    Izumi, Kosuke; Brett, Maggie; Nishi, Eriko; Drunat, Séverine; Tan, Ee-Shien; Fujiki, Katsunori; Lebon, Sophie; Cham, Breana; Masuda, Koji; Arakawa, Michiko; Jacquinet, Adeline; Yamazumi, Yusuke; Chen, Shu-Ting; Verloes, Alain; Okada, Yuki; Katou, Yuki; Nakamura, Tomohiko; Akiyama, Tetsu; Gressens, Pierre; Foo, Roger; Passemard, Sandrine; Tan, Ene-Choo; El Ghouzzi, Vincent; Shirahige, Katsuhiko

    2016-08-04

    Cellular homeostasis is maintained by the highly organized cooperation of intracellular trafficking systems, including COPI, COPII, and clathrin complexes. COPI is a coatomer protein complex responsible for intracellular protein transport between the endoplasmic reticulum and the Golgi apparatus. The importance of such intracellular transport mechanisms is underscored by the various disorders, including skeletal disorders such as cranio-lenticulo-sutural dysplasia and osteogenesis imperfect, caused by mutations in the COPII coatomer complex. In this article, we report a clinically recognizable craniofacial disorder characterized by facial dysmorphisms, severe micrognathia, rhizomelic shortening, microcephalic dwarfism, and mild developmental delay due to loss-of-function heterozygous mutations in ARCN1, which encodes the coatomer subunit delta of COPI. ARCN1 mutant cell lines were revealed to have endoplasmic reticulum stress, suggesting the involvement of ER stress response in the pathogenesis of this disorder. Given that ARCN1 deficiency causes defective type I collagen transport, reduction of collagen secretion represents the likely mechanism underlying the skeletal phenotype that characterizes this condition. Our findings demonstrate the importance of COPI-mediated transport in human development, including skeletogenesis and brain growth. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  8. Charcot-Marie-Tooth disease due to a de novo mutation of the RAB7 gene

    NARCIS (Netherlands)

    Meggouh, F.; Bienfait, H. M. E.; Weterman, M. A. J.; de Visser, M.; Baas, F.

    2006-01-01

    We report a 32-year-old patient with Charcot-Marie-Tooth (CMT2B) including foot ulcerations. Genetic analysis identified a de novo mutation in the small GTP-ase late endosomal RAB7 gene, consisting of a c.471G>C, p.Lys157Asn missense mutation. This observation strongly supports the hypothesis that

  9. Mutation breeding in chickpea

    International Nuclear Information System (INIS)

    2009-01-01

    Chickpea is an important food legume in Turkey. Turkey is one of the most important gene centers in the world for legumes. The most widely known characteristic of chickpea is that it is an important vegetable protein source used in human and animal nutrition. However, the dry grains of chickpea, has 2-3 times more protein than our traditional food of wheat. In addition, cheakpea is also energy source because of its high carbohydrate content. It is very rich in some vitamin and mineral basis. In the plant breeding, mutation induction has become an effective way of supplementing existing germplasm and improving cultivars. Many successful examples of mutation induction have proved that mutation breeding is an effective and important approach to food legume improvement. The induced mutation technique in chickpea has proved successful and good results have been attained. Realizing the potential of induced mutations, a mutation breeding programme was initiated at the Nuclear Agriculture Section of the Saraykoey Nuclear Research and Training Center in 1994. The purpose of the study was to obtain high yielding chickpea mutants with large seeds, good cooking quality and high protein content. Beside this some characters such as higher adaptation ability, tolerant to cold and drought, increased machinery harvest type, higher yield, resistant to diseases especially to antracnose and pest were investigated too. Parents varieties were ILC-482, AK-7114 and AKCIN-91 (9 % seed moisture content and germination percentage 98 %) in these experiments. The irradiation doses were 0 (control), 50, 100, 150, 200, 250, 300, 350, 400, 500 ve 600 Gy for greenhouse experiments and 0 (control), 50, 100, 150, 200, 250, 300, 350 ve 400 Gy for field experiments, respectively. One thousand seeds for per treatment were sown in the field for the M 1 . At maturity, 3500 single plants were harvested and 20 seeds were taken from each M 1 plant and planted in the following season. During plant growth

  10. Amplification-refractory mutation system (ARMS) analysis of point mutations.

    Science.gov (United States)

    Little, S

    2001-05-01

    The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base changes or small deletions. ARMS is based on the use of sequence-specific PCR primers that allow amplification of test DNA only when the target allele is contained within the sample. Following an ARMS reaction the presence or absence of a PCR product is diagnostic for the presence or absence of the target allele. The protocols detailed here outline methods that can be used to analyze human genomic DNA for one or more mutations. The Basic Protocol describes the development and application of an ARMS test for a single mutation; the Alternate Protocol extends this to multiplex ARMS for the analysis of two or more mutations. The Support Protocol describes a rapid DNA extraction method from blood or mouthwash samples that yields DNA compatible with the type of tests described. The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base change The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base change.

  11. Adaptive evolution by recombination is not associated with increased mutation rates in Maize streak virus.

    Science.gov (United States)

    Monjane, Adérito L; Pande, Daniel; Lakay, Francisco; Shepherd, Dionne N; van der Walt, Eric; Lefeuvre, Pierre; Lett, Jean-Michel; Varsani, Arvind; Rybicki, Edward P; Martin, Darren P

    2012-12-27

    observed similar strand specific mutation biases arising predominantly from imbalances in the complementary mutations G → T: C → A. While our results suggest that recombination does not strongly influence mutation rates in MSV, they indicate that high geminivirus mutation rates are at least partially attributable to increased susceptibility of all geminivirus genomes to oxidative damage while in a single stranded state.

  12. Adaptive evolution by recombination is not associated with increased mutation rates in Maize streak virus

    Directory of Open Access Journals (Sweden)

    Monjane Adérito L

    2012-12-01

    the mutation spectra of MSV and TYLCV we observed similar strand specific mutation biases arising predominantly from imbalances in the complementary mutations G → T: C → A. Conclusions While our results suggest that recombination does not strongly influence mutation rates in MSV, they indicate that high geminivirus mutation rates are at least partially attributable to increased susceptibility of all geminivirus genomes to oxidative damage while in a single stranded state.

  13. Strong Ideal Convergence in Probabilistic Metric Spaces

    Indian Academy of Sciences (India)

    In the present paper we introduce the concepts of strongly ideal convergent sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and establish some basic facts. Next, we define the strong ideal limit points and the strong ideal cluster points of a sequence in this ...

  14. Strong ideal convergence in probabilistic metric spaces

    Indian Academy of Sciences (India)

    In the present paper we introduce the concepts of strongly ideal convergent sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and establish some basic facts. Next, we define the strong ideal limit points and the strong ideal cluster points of a sequence in this ...

  15. Induced mutations in citrus

    International Nuclear Information System (INIS)

    Spiegel-Roy, P.; Vardi, Aliza

    1990-01-01

    Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

  16. Remnants of strong tidal interactions

    International Nuclear Information System (INIS)

    Mcglynn, T.A.

    1990-01-01

    This paper examines the properties of stellar systems that have recently undergone a strong tidal shock, i.e., a shock which removes a significant fraction of the particles in the system, and where the shocked system has a much smaller mass than the producer of the tidal field. N-body calculations of King models shocked in a variety of ways are performed, and the consequences of the shocks are investigated. The results confirm the prediction of Jaffe for shocked systems. Several models are also run where the tidal forces on the system are constant, simulating a circular orbit around a primary, and the development of tidal radii under these static conditions appears to be a mild process which does not dramatically affect material that is not stripped. The tidal radii are about twice as large as classical formulas would predict. Remnant density profiles are compared with a sample of elliptical galaxies, and the implications of the results for the development of stellar populations and galaxies are considered. 38 refs

  17. John Strong - 1941-2006

    CERN Document Server

    2006-01-01

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on 31 July, a few days before his 65th birthday. John started his career and obtained his PhD in a group from Westfield College, initially working on experiments at Rutherford Appleton Laboratory (RAL). From the early 1970s onwards, however, his research was focused on experiments in CERN, with several particularly notable contributions. The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras (a type of television camera) to record the sparks in the spark chambers. This highly automated system allowed Omega to be used in a similar way to bubble chambers. He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems. In these experiments the Westfield group joined forces with Italian colleagues to measure the form factors of the pion and the kaon, and the lifetime of some of the newly discovered charm particles. Such h...

  18. Strong seismic ground motion propagation

    International Nuclear Information System (INIS)

    Seale, S.; Archuleta, R.; Pecker, A.; Bouchon, M.; Mohammadioun, G.; Murphy, A.; Mohammadioun, B.

    1988-10-01

    At the McGee Creek, California, site, 3-component strong-motion accelerometers are located at depths of 166 m, 35 m and 0 m. The surface material is glacial moraine, to a depth of 30.5 m, overlying homfels. Accelerations were recorded from two California earthquakes: Round Valley, M L 5.8, November 23, 1984, 18:08 UTC and Chalfant Valley, M L 6.4, July 21, 1986, 14:42 UTC. By separating out the SH components of acceleration, we were able to determine the orientations of the downhole instruments. By separating out the SV component of acceleration, we were able to determine the approximate angle of incidence of the signal at 166 m. A constant phase velocity Haskell-Thomson model was applied to generate synthetic SH seismograms at the surface using the accelerations recorded at 166 m. In the frequency band 0.0 - 10.0 Hz, we compared the filtered synthetic records to the filtered surface data. The onset of the SH pulse is clearly seen, as are the reflections from the interface at 30.5 m. The synthetic record closely matches the data in amplitude and phase. The fit between the synthetic accelerogram and the data shows that the seismic amplification at the surface is a result of the contrast of the impedances (shear stiffnesses) of the near surface materials

  19. Mutation Breeding Newsletter. No. 39

    International Nuclear Information System (INIS)

    1992-01-01

    This n