Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

A Randomized, Double-blind, Placebo-Controlled Study of Latrepirdine in Patients With Mild to Moderate Huntington Disease

Experimentele farmacotherapi

CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

Objective: Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. Methods: We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. Results: An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a wellbehaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. Conclusions: Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors. Copyright © 2012 by AAN Enterprises, Inc

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

β-Defensin genomic copy number does not influence the age of onset in Huntington's Disease

none498siHuntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the abnormal expansion of a CAG triplet repeat tract in the huntingtin gene. While the length of this CAG expansion is the major determinant of the age of onset (AO), other genetic factors have also been shown to play a modulatory role. Recent evidence suggests that neuroinflammations is a pivotal factor in the pathogenesis of HD, and that targeting this process may have important therapeutic ramifications. The human β-defensin 2 (hBD2)- encoded by DEFB4- is an antimicrobial peptide that exhibits inducible expression in astrocytes during inflammation and is an important regulator of innate and adaptive immune response. Therefore, DEFB4 may contribute to the neuroinflammatory processes observed in HD.openVittori A, Orth M, Roos RA, Outeiro TF, Giorgini F, Hollox EJ, Bachoud-Levi AC, Bentivoglio AR, Biunno I, Bonelli RM, Burgunder JM, Dunnett SB, Ferreira JJ, Handley OJ, Heiberg A, Illmann T, Landwehrmeyer GB, Levey J, Martinez-Jaurrieta MD, Nielsen JE, Pro Koivisto S, Piiiviirinta M, Roos RA, Sebastian AR, Tabrizi SJ, Vandenberghe W, Verellen-Dumoulin C, Zaremba J, Uhrova T, Wahlstrom J, Barth K, Correia-Guedes L, Finisterra AM, Bascuiiana Garde M, Betz S, Bos R, Ecker D, Handley OJ, Held C, Koppers K, Laura M, Descals AM, Mestre T, Monza D, Townhill J, Padieu H, Paterski L, Peppa N, Rialland A, Røren N, Sasinkova P, Trigo Cubillo P, van Walsem M, Witjes-Ane MN, Yudina E, Zielonka D, Zielonka E, Zinzi P, Bonelli RM, Herranhof B, HOd A, Kapfhammer HP, Koppitz M, Magnet M, Otti D, Painold A, Reisinge K, Scheib M, Hecht K, Lilek S, Muller N, Schoggl H, Ullah J, Ribal P, Verellen-Dumoulin C, Klempff J, Majerova V, Roth J, Hjermind LE, Jakobsen O, Vinthev-Jensen T, Larsen IU, Nielsen JE, Stokholm J, Hiivola H, Martikainen K, Tuuha K, Santala M, Milkereit E, Kosinski CM, Probst D, Reetz K, Sass C, Schiefer J, Schlangen C, Werner CJ, Andrich J, Ellrichmann G, Hoffmann R, Kaminski B, Saft C, Stamm C, Lange H, Lohle M, Schmidt S, Storch A, Wolz A, Wolz M, Capetian P, Lambeck J, Zucker B, Boelmans K, Ganos C, Hidding U, Lewerenz J, Miinchau A, Orth M, Schmalfeld J, Stubbe L, Zittel S, Heinicke W, Ribbat M, Longinus B, Miihlau M, Peinemann A, Stiidtler M, Weindl A, Winkelmann J, Ziegler C, Bechtel N, Beckmann H, Bohlen S, Holzner E, Lange H, Reilmann R, Rohm S, Rumpf S, Schepers S, Dose M, Leythaeuser G, Marquard R, Raab T, Schrenk C, Schuierer M, Barth K, Buck A, Ecker D, Eschenbach C, Held C, Landwehrmeyer B, Lezius F, Nepper S, Niess A, Orth M, Schwenk D, Siissmuth S, Trautmann S, Weydt P, Cormio C, de Tommaso M, Sciruicchio V, Serpino C, Ghelli E, Ginestroni A, Bertini E, Massaro F, Mechi C, Paganini M, Piacentini S, Pradella S, Romoli AM, Sorbi S, Abbruzzese G, Ferrandes MB, Di Maria E, Ferrandes G, Mandich P, Marchese R, Di Donato S, Gellera C, Genitrini S, Mariotti C, Nanetti L, Monza D, Soliveri P, Tomasello C, De Michele G, DiMaio L, Massarelli M, Rinaldi C, Roca A, Rossi F, Russo CV, Salvatore E, Sorrentino P, Tucci T, De Nicola A, Elifani F, Petrollini M, Martino T, Lovo F, Squitieri F, Bentivoglio AR, Catalli C, Di Giacopo R, Fasano A, Frontali M, Guidubaldi A, Ialongo T, Jacopini G, Loria G, Piano C, Piccininni C, Quaranta D, Romano S, Soleti F, Spadaro M, Zinzi P, van Hout MS, van Vugt JP, de Weert A, Bolwijn JJ, Neurologie P, Dekker M, Neurologie P, Leenders KL, van Oostrom JC, Bos R, Dumas EM, Jurgens CK, van den Bogaard SJ, Roos RA, 't Hart EP, Kremer B, Verstappen CC, Heiberg A, van Walsem MR, Frich J, Aaserud O, Wehus R, Bjørgo K, Fannemel M, Gørvell P, Lorentzen E, Koivisto SP, Retterstøl L, Stokke B, Bjørnevoll I, Sando SB, Dziadkiewicz A, Nowak M, Robowski P, Sitek E, Slawek J, Soltan W, Szinwelski M, Blaszczyk M, Boczarska-Jedynak M, Ciach-Wysocka E, Gorzkowska A, Jasinska-Myga B, Opala G, Klodowska G, Stompel D, Ciach-Wysocka E, Banaszkiewicz K, Boewiriska D, Bojakowska-Jaremek K, Neurologii A, Dec M, Krawczyk M, Rudziriska M, Szczudlik A, Szczygiel E, Wasielewska A, Wojcik M, Wojcik M, Bryl A, Ciesielska A, Klimberg A, Marcinkowski J, Samara H, Sempolowicz J, Zielonka D, Janik P, Kalbarczyk A, Kwiecinski H, Jamrozik Z, Antczak J, Jachinska K, Krysa W, Rakowicz M, Richter P, Rola R, Ryglewicz D, Sienkiewicz-Jarosz H, Sulek A, Witkowski G, Zdzienicka E, Zaremba J, Zieora-Jakutowicz K, Coelho M, Correia-Guedes L, Ferreira JJ, Mestre T, Mendes T, Valadas A, Andrade C, Joao PS, Gago M, Garrett C, Joao PS, Guerra MR, Joao PS, Solis P, Herrera CD, Garcia PM, Cubo E, Mariscal N, Sanchez J, Barrero FJ, Alonso-Frech F, Perez MR, Fenollar M, Garda R, Rivera SV, Villanueva C, Alegre J, Bascuiiana M, Ventura MF, Ribas GG, Moreno JL, Cubillo PT, Rufz PJ, Frech FA, Dfaz J, Guerrero R, Dfaz J, Artiga MJ, Dfaz J, Sanchez V, Alcaraz LF, de Ia Arrixaca V, Manzanares S, de Ia Arrixaca V, Perea MF, Reinante G, Arrixaca Ia, Torres MM, Moreau LV, de Ia Arrixaca V, Barbera MA, Guia DB, Hernanz LC, Catena JL, Sebastian R, Ferrer PQ, Carruesco GT, Bas J, Busquets N, Calopa M, Buongiorno MT, Munoz E, Elorza MD, Lopez CD, Terol DS, Robert MF, Rufz BG, Casado AG, Martinez IH, Viladrich CM, Pons R, Roca E, Llesoy JR, Idiago JM, Vergara MR, Garcia SS, Riballo AV, Hoglund A, Palhagen SE, Paucar M, Sandstrom B, Svenningsson P, Reza-Soltani TW, Burgunder JM, Kaelin A, Romero I, Schupbach M, Stebler Y, Zaugg SW, Akhtar S, Crooks J, Curtis A, de Souza J, Rickards H, Wright J, Barker RA, Di Pietro A, Fisher K, Goodman AO, Hill S, Kershaw A, Mason S, O'Keefe D, Swain R, Guzman NV, Busse M, Butcher C, Clenaghan C, Dunnett S, Fullam R, Jones L, Jones U, Khalil H, Minster S, Owen M, Hunt S, Price K, Rosser A, Townhill J, Edwards M, Ho C, McGill M, Pearson P, Porteous M, Brockie P, Foster J, Johns N, McKenzie S, Rothery J, Thomas G, Yates S, Burrows L, Chu C, Fletcher A, Gallantrae D, Harding A, Hamer S, Kraus A, Laver F, Longthorpe M, Markova I, Raman A, Silva M, Thomson A, Wild S, Yardumian P, Hobson E, Jamieson S, Musgrave H, Rowett L, Toscano J, Wild S, Yardumian P, Clayton C, Dipple H, Middleton J, Patino D, Andrews T, Dougherty A, Kavalier F, Golding C, Laing H, Lashwood A, Robertson D, Ruddy D, Whaite A, Santhouse A, Andrews T, Bruno S, Doherty K, Lahiri N, Novak M, Patel A, Rosser E, Tabrizi S, Taylor R, Warner T, Wild E, Arran N, Bek J, Callaghan J, Craufurd D, Fullam R, Howard L, Hare M, Huson S, Johnson L, Jones M, Murphy H, Oughton E, Partington-Janes L, Rogers D, Snowden J, Sollom A, Stopford C, Thompson J, Trender-Gerhard I.Vittori, A; Orth, M; Roos, Ra; Outeiro, Tf; Giorgini, F; Hollox, Ej; Bachoud-Levi, Ac; Bentivoglio, Ar; Biunno, I; Bonelli, Rm; Burgunder, Jm; Dunnett, Sb; Ferreira, Jj; Handley, Oj; Heiberg, A; Illmann, T; Landwehrmeyer, Gb; Levey, J; Martinez-Jaurrieta, Md; Nielsen, Je; Pro Koivisto, S; Piiiviirinta, M; Roos, Ra; Sebastian, Ar; Tabrizi, Sj; Vandenberghe, W; Verellen-Dumoulin, C; Zaremba, J; Uhrova, T; Wahlstrom, J; Barth, K; Correia-Guedes, L; Finisterra, Am; Bascuiiana Garde, M; Betz, S; Bos, R; Ecker, D; Handley, Oj; Held, C; Koppers, K; Laura, M; Descals, Am; Mestre, T; Monza, D; Townhill, J; Padieu, H; Paterski, L; Peppa, N; Rialland, A; Røren, N; Sasinkova, P; Trigo Cubillo, P; van Walsem, M; Witjes-Ane, Mn; Yudina, E; Zielonka, D; Zielonka, E; Zinzi, P; Bonelli, Rm; Herranhof, B; Hod, A; Kapfhammer, Hp; Koppitz, M; Magnet, M; Otti, D; Painold, A; Reisinge, K; Scheib, M; Hecht, K; Lilek, S; Muller, N; Schoggl, H; Ullah, J; Ribal, P; Verellen-Dumoulin, C; Klempff, J; Majerova, V; Roth, J; Hjermind, Le; Jakobsen, O; Vinthev-Jensen, T; Larsen, Iu; Nielsen, Je; Stokholm, J; Hiivola, H; Martikainen, K; Tuuha, K; Santala, M; Milkereit, E; Kosinski, Cm; Probst, D; Reetz, K; Sass, C; Schiefer, J; Schlangen, C; Werner, Cj; Andrich, J; Ellrichmann, G; Hoffmann, R; Kaminski, B; Saft, C; Stamm, C; Lange, H; Lohle, M; Schmidt, S; Storch, A; Wolz, A; Wolz, M; Capetian, P; Lambeck, J; Zucker, B; Boelmans, K; Ganos, C; Hidding, U; Lewerenz, J; Miinchau, A; Orth, M; Schmalfeld, J; Stubbe, L; Zittel, S; Heinicke, W; Ribbat, M; Longinus, B; Miihlau, M; Peinemann, A; Stiidtler, M; Weindl, A; Winkelmann, J; Ziegler, C; Bechtel, N; Beckmann, H; Bohlen, S; Holzner, E; Lange, H; Reilmann, R; Rohm, S; Rumpf, S; Schepers, S; Dose, M; Leythaeuser, G; Marquard, R; Raab, T; Schrenk, C; Schuierer, M; Barth, K; Buck, A; Ecker, D; Eschenbach, C; Held, C; Landwehrmeyer, B; Lezius, F; Nepper, S; Niess, A; Orth, M; Schwenk, D; Siissmuth, S; Trautmann, S; Weydt, P; Cormio, C; de Tommaso, M; Sciruicchio, V; Serpino, C; Ghelli, E; Ginestroni, A; Bertini, E; Massaro, F; Mechi, C; Paganini, M; Piacentini, S; Pradella, S; Romoli, Am; Sorbi, S; Abbruzzese, G; Ferrandes, Mb; Di Maria, E; Ferrandes, G; Mandich, P; Marchese, R; Di Donato, S; Gellera, C; Genitrini, S; Mariotti, C; Nanetti, L; Monza, D; Soliveri, P; Tomasello, C; De Michele, G; Dimaio, L; Massarelli, M; Rinaldi, C; Roca, A; Rossi, F; Russo, Cv; Salvatore, E; Sorrentino, P; Tucci, T; De Nicola, A; Elifani, F; Petrollini, M; Martino, T; Lovo, F; Squitieri, F; Bentivoglio, Ar; Catalli, C; Di Giacopo, R; Fasano, A; Frontali, M; Guidubaldi, A; Ialongo, T; Jacopini, G; Loria, G; Piano, C; Piccininni, C; Quaranta, D; Romano, S; Soleti, F; Spadaro, M; Zinzi, P; van Hout, Ms; van Vugt, Jp; de Weert, A; Bolwijn, Jj; Neurologie, P; Dekker, M; Neurologie, P; Leenders, Kl; van Oostrom, Jc; Bos, R; Dumas, Em; Jurgens, Ck; van den Bogaard, Sj; Roos, Ra; 't Hart, Ep; Kremer, B; Verstappen, Cc; Heiberg, A; van Walsem, Mr; Frich, J; Aaserud, O; Wehus, R; Bjørgo, K; Fannemel, M; Gørvell, P; Lorentzen, E; Koivisto, Sp; Retterstøl, L; Stokke, B; Bjørnevoll, I; Sando, Sb; Dziadkiewicz, A; Nowak, M; Robowski, P; Sitek, E; Slawek, J; Soltan, W; Szinwelski, M; Blaszczyk, M; Boczarska-Jedynak, M; Ciach-Wysocka, E; Gorzkowska, A; Jasinska-Myga, B; Opala, G; Klodowska, G; Stompel, D; Ciach-Wysocka, E; Banaszkiewicz, K; Boewiriska, D; Bojakowska-Jaremek, K; Neurologii, A; Dec, M; Krawczyk, M; Rudziriska, M; Szczudlik, A; Szczygiel, E; Wasielewska, A; Wojcik, M; Wojcik, M; Bryl, A; Ciesielska, A; Klimberg, A; Marcinkowski, J; Samara, H; Sempolowicz, J; Zielonka, D; Janik, P; Kalbarczyk, A; Kwiecinski, H; Jamrozik, Z; Antczak, J; Jachinska, K; Krysa, W; Rakowicz, M; Richter, P; Rola, R; Ryglewicz, D; Sienkiewicz-Jarosz, H; Sulek, A; Witkowski, G; Zdzienicka, E; Zaremba, J; Zieora-Jakutowicz, K; Coelho, M; Correia-Guedes, L; Ferreira, Jj; Mestre, T; Mendes, T; Valadas, A; Andrade, C; Joao, Ps; Gago, M; Garrett, C; Joao, Ps; Guerra, Mr; Joao, Ps; Solis, P; Herrera, Cd; Garcia, Pm; Cubo, E; Mariscal, N; Sanchez, J; Barrero, Fj; Alonso-Frech, F; Perez, Mr; Fenollar, M; Garda, R; Rivera, Sv; Villanueva, C; Alegre, J; Bascuiiana, M; Ventura, Mf; Ribas, Gg; Moreno, Jl; Cubillo, Pt; Rufz, Pj; Frech, Fa; Dfaz, J; Guerrero, R; Dfaz, J; Artiga, Mj; Dfaz, J; Sanchez, V; Alcaraz, Lf; de Ia Arrixaca, V; Manzanares, S; de Ia Arrixaca, V; Perea, Mf; Reinante, G; Arrixaca, Ia; Torres, Mm; Moreau, Lv; de Ia Arrixaca, V; Barbera, Ma; Guia, Db; Hernanz, Lc; Catena, Jl; Sebastian, R; Ferrer, Pq; Carruesco, Gt; Bas, J; Busquets, N; Calopa, M; Buongiorno, Mt; Munoz, E; Elorza, Md; Lopez, Cd; Terol, Ds; Robert, Mf; Rufz, Bg; Casado, Ag; Martinez, Ih; Viladrich, Cm; Pons, R; Roca, E; Llesoy, Jr; Idiago, Jm; Vergara, Mr; Garcia, Ss; Riballo, Av; Hoglund, A; Palhagen, Se; Paucar, M; Sandstrom, B; Svenningsson, P; Reza-Soltani, Tw; Burgunder, Jm; Kaelin, A; Romero, I; Schupbach, M; Stebler, Y; Zaugg, Sw; Akhtar, S; Crooks, J; Curtis, A; de Souza, J; Rickards, H; Wright, J; Barker, Ra; Di Pietro, A; Fisher, K; Goodman, Ao; Hill, S; Kershaw, A; Mason, S; O'Keefe, D; Swain, R; Guzman, Nv; Busse, M; Butcher, C; Clenaghan, C; Dunnett, S; Fullam, R; Jones, L; Jones, U; Khalil, H; Minster, S; Owen, M; Hunt, S; Price, K; Rosser, A; Townhill, J; Edwards, M; Ho, C; Mcgill, M; Pearson, P; Porteous, M; Brockie, P; Foster, J; Johns, N; Mckenzie, S; Rothery, J; Thomas, G; Yates, S; Burrows, L; Chu, C; Fletcher, A; Gallantrae, D; Harding, A; Hamer, S; Kraus, A; Laver, F; Longthorpe, M; Markova, I; Raman, A; Silva, M; Thomson, A; Wild, S; Yardumian, P; Hobson, E; Jamieson, S; Musgrave, H; Rowett, L; Toscano, J; Wild, S; Yardumian, P; Clayton, C; Dipple, H; Middleton, J; Patino, D; Andrews, T; Dougherty, A; Kavalier, F; Golding, C; Laing, H; Lashwood, A; Robertson, D; Ruddy, D; Whaite, A; Santhouse, A; Andrews, T; Bruno, S; Doherty, K; Lahiri, N; Novak, M; Patel, A; Rosser, E; Tabrizi, S; Taylor, R; Warner, T; Wild, E; Arran, N; Bek, J; Callaghan, J; Craufurd, D; Fullam, R; Howard, L; Hare, M; Huson, S; Johnson, L; Jones, M; Murphy, H; Oughton, E; Partington-Janes, L; Rogers, D; Snowden, J; Sollom, A; Stopford, C; Thompson, J; Trender-Gerhard, I

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure

Optimization of adsorptive removal of α-toluic acid by CaO2 nanoparticles using response surface methodology

The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO2) nanoparticles using response surface methodology (RSM). CaO2 nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO2 nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO2 nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO2 adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R2) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction