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

The role of double-strand break repair - insights from human genetics

The efficient repair of DNA double-strand breaks is crucial in safeguarding the genomic integrity of organisms. Responses to double-strand breaks include complex signal-transduction, cell-cycle-checkpoint and repair pathways. Defects in these pathways lead to several human disorders with pleiotropic clinical features. Dissection of the molecular basis that underlies the diverse clinical features is enhancing our understanding of the damage-response mechanisms and their role in development, and might ultimately facilitate treatment

Discrepancies in reporting the CAG repeat lengths for Huntington's disease.

Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original results from 121 laboratories across 15 countries. We report on 1326 duplicate results; a discrepancy in reporting the upper allele occurred in 51% of cases, this reduced to 13.3% and 9.7% when we applied acceptable measurement errors proposed by the American College of Medical Genetics and the Draft European Best Practice Guidelines, respectively. Duplicate results were available for 1250 lower alleles; discrepancies occurred in 40% of cases. Clinically significant discrepancies occurred in 4.0% of cases with a potential unexplained misdiagnosis rate of 0.3%. There was considerable variation in the discrepancy rate among 10 of the countries participating in this study. Out of 1326 samples, 348 were re-analysed by an accredited diagnostic laboratory, based in Germany, with concordance rates of 93% and 94% for the upper and lower alleles, respectively. This became 100% if the acceptable measurement errors were applied. The central laboratory correctly reported allele sizes for six standard reference samples, blind to the known result. Our study differs from external quality assessment (EQA) schemes in that these are duplicate results obtained from a large sample of patients across the whole diagnostic range. We strongly recommend that laboratories state an error rate for their measurement on the report, participate in EQA schemes and use reference materials regularly to adjust their own internal standards

Discrepancies in reporting the CAG repeat lengths for Huntington's disease.

Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original results from 121 laboratories across 15 countries. We report on 1326 duplicate results; a discrepancy in reporting the upper allele occurred in 51% of cases, this reduced to 13.3% and 9.7% when we applied acceptable measurement errors proposed by the American College of Medical Genetics and the Draft European Best Practice Guidelines, respectively. Duplicate results were available for 1250 lower alleles; discrepancies occurred in 40% of cases. Clinically significant discrepancies occurred in 4.0% of cases with a potential unexplained misdiagnosis rate of 0.3%. There was considerable variation in the discrepancy rate among 10 of the countries participating in this study. Out of 1326 samples, 348 were re-analysed by an accredited diagnostic laboratory, based in Germany, with concordance rates of 93% and 94% for the upper and lower alleles, respectively. This became 100% if the acceptable measurement errors were applied. The central laboratory correctly reported allele sizes for six standard reference samples, blind to the known result. Our study differs from external quality assessment (EQA) schemes in that these are duplicate results obtained from a large sample of patients across the whole diagnostic range. We strongly recommend that laboratories state an error rate for their measurement on the report, participate in EQA schemes and use reference materials regularly to adjust their own internal standards

Observing Huntington's disease: the European Huntington's Disease Network's REGISTRY.

none642sinoneOrth M, Handley OJ, Schwenke C, Dunnett S, Wild EJ, Tabrizi SJ, Landwehrmeyer GB, Bachoud-Lévi AC, Bentivoglio AR, Biunno I, Bonelli R, Burgunder JM, Dunnett SB, Ferreira JJ, Giuliano J, Handley OJ, Heiberg A, Illmann T, van Kammen D, Landwehrmeye GB, Levey J, Nielsen JE, Päivärinta M, Roos RA, Sebastián AR, Tabrizi SJ, Vandenberghe W, Verellen-Dumoulin C, Zaremba J, Uhrova T, Wahlström J, Schwenke C, Orth M, Illmann T, Wallner M, Barth K, Guedes LC, Finisterra AM, Garde MB, Bos R, Burg S, Ecker D, Handley OJ, Held C, Koppers K, Laurà M, Descals AM, McLean T, Mestre T, Minster S, Monza D, Townhill J, Orth M, Padieu H, Paterski L, Peppa N, Koivisto SP, Rialland A, Røren N, Sasinková P, Cubillo PT, Tritsch C, van Walsem MR, Witjes-Ané MN, Yudina E, Zielonka D, Zielonka E, Zinzi P, Bonelli RM, Herranhof B, Holl A, Kapfhammer HP, Koppitz M, Magnet M, Otti D, Painold A, Reisinger K, Scheibl M, Hecht K, Lilek S, Müller N, Schöggl H, Ullah J, Brugger F, Hepperger C, Hotter A, Mahlknecht P, Nocker M, Seppi K, Wenning G, Buratti L, Hametner EM, Holas C, Hussl A, Mair K, Poewe W, Wolf E, Zangerl A, Braunwarth EM, Lilek S, Sinadinosa D, Walleczek AM, Bonelli RM, Ladurner G, Staffen W, Ribaï P, Verellen-Dumoulin C, Flamez A, Morez V, de Raedt S, Boogaerts A, Vandenberghe W, van Reijen D, Klempíř J, Kucharík M, Roth J, Šenkárová Z, Hasholt L, Hjermind LE, Jakobsen O, Nørremølle A, Sørensen SA, Stokholm J, Nielsen J, Hiivola H, Martikainen K, Tuuha K, Peippo M, Sipponen M, Ignatius J, Kärppä M, Åman J, Santala M, Allain P, Guérid MA, Gohier B, Olivier A, Prundean A, Scherer-Gagou C, Verny C, Babiloni B, Debruxelles S, Goizet C, Lafoucrière D, De Bruycker C, Carette AS, Decorte E, Delval A, Delliaux M, Dujardin K, Peter M, Plomhouse L, Simonin C, Thibault-Tanchou S, Bellonet M, Duru C, Krystkowiak P, Roussel M, Wannepain S, Azulay JP, Chabot C, Delphini M, Eusebio A, Grosjean H, Mundler L, Nowak M, Rudolf G, Steinmetz G, Tranchant C, Wagner C, Zimmermann MA, Calvas F, Cheriet S, Démonet JF, Galitzky M, Kosinski CM, Milkereit E, Probst D, Sass C, Schiefer J, Schlangen C, Werner CJ, Gelderblom H, Priller J, Prüss H, Spruth EJ, Andrich J, Hoffmann R, Kraus PH, Muth S, Prehn C, Saft C, Salmen S, Stamm C, Steiner T, Strassburger K, Lange H, Friedrich A, Hunger U, Löhle M, Schmidt S, Storch A, Wolz A, Wolz M, Lambeck J, Zucker B, Boelmans K, Ganos C, Hidding U, Lewerenz J, Münchau A, Orth M, Schmalfeld J, Stubbe L, Zittel S, Diercks G, Gorzolla H, Schrader C, Heinicke W, Ribbat M, Longinus B, Bürk K, Möller JC, Rissling I, Peinemann A, Städtler M, Weindl A, Bechtel N, Beckmann H, Bohlen S, Hölzner E, Lange H, Reilmann R, Rohm S, Rumpf S, Schepers S, Beister A, Dose M, Hammer K, Kieni J, Leythaeuser G, Marquard R, Raab T, Richter S, Selimbegovic-Turkovic A, Schrenk C, Schuierer M, Wiedemann A, Barth K, Buck A, Connemann J, Ecker D, Eschenbach C, Held C, Landwehrmeyer B, Lezius F, Nepper S, Niess A, Orth M, Süssmuth S, Trautmann S, Weydt P, Cormio C, Difruscolo O, Sciruicchio V, Serpino C, de Tommaso M, Capellari S, Cortelli P, Gallassi R, Poda R, Rizzo G, Scaglione C, Bertini E, Ghelli E, Ginestroni A, Massaro F, Mechi C, Paganini M, Piacentini S, Pradella S, Romoli AM, Sorbi S, Abbruzzese G, di Poggio MB, Di Maria E, Ferrandes G, Mandich P, Marchese R, Albanese A, Di Bella D, Di Donato S, Gellera C, Genitrini S, Mariotti C, Monza D, Nanetti L, Paridi D, Soliveri P, Tomasello C, De Michele G, Di Maio L, Rinaldi C, Russo CV, Salvatore E, Tucci T, Cannella M, Codella V, De Gregorio F, De Nicola N, Martino T, Simonelli M, Squitieri F, Bentivoglio AR, Catalli C, Di Giacopo R, Fasano A, Frontali M, Guidubaldi A, Ialongo T, Jacopini G, Loria G, Modoni A, Piano C, Chiara P, Quaranta D, Romano S, Soleti F, Spadaro M, Zinzi P, van Hout MS, van Vugt JP, de Weert AM, Bolwijn JJ, Dekker M, Leenders KL, van Oostrom JC, Bos R, Dumas EM, Jurgens CK, van den Bogaard SJ, Roos RA, 't Hart EP, Witjes-Ané MN, Kremer B, Verstappen CC, Heiberg A, van Walsem MR, Frich J, Wehus R, Aaserud O, Borgerød N, Bjørgo K, Fannemel M, Gørvell P, Pro Koivisto S, Retterstøl L, Overland T, Stokke B, Bjørnevoll I, Sando SB, Blinkenberg EØ, Hauge E, Tyvoll H, Sitek E, Slawek J, Soltan W, Boczarska-Jedynak M, Jasinska-Myga B, Opala G, Kłodowska-Duda G, Banaszkiewicz K, Szczudlik A, Rudzińska M, Wójcik M, Dec M, Krawczyk M, Bryl A, Ciesielska A, Klimberg A, Marcinkowski J, Sempołowicz J, Zielonka D, Samara H, Janik P, Kalbarczyk A, Kwiecinski H, Jamrozik Z, Antczak J, Jachinska K, Rakowicz M, Richter P, Ryglewicz D, Witkowski G, Zdzienicka E, Zaremba J, Sułek A, Krysa W, Júlio F, Januário C, Mestre T, Guedes L, Coelho M, Mendes T, Valadas A, Ferreira JJ, Timóteo Â, Costa C, Vale J, Cavaco S, Damásio J, Magalhães M, Gago M, Garrett C, Guerra MR, Solis P, Herrera CD, Garcia PM, Barrero F, Morales B, Cubo E, Mariscal N, Alonso-Frech F, Perez MR, Fenollar M, García RG, Quiroga PP, Rivera SV, Villanueva C, Bascuñana M, Ventura MF, Ribas GG, de Yébenes JG, Moreno JL, Cubillo PT, Ruíz PJ, Martínez-Descals A, Artiga MJ, Sánchez V, Perea MF, Lorenza F, Torres MM, Reinante G, Moreau LV, Barbera MA, Guia DB, Hernanz LC, Catena JL, Sebastián AR, Ferrer PQ, Carruesco GT, Bas J, Busquets N, Calopa M, Buongiorno MT, Muñoz E, Elorza MD, López CD, Terol SD, Robert MF, Ruíz BG, Casado AG, Martínez IH, Viladrich CM, Pons i Càrdenas R, Roca E, Llesoy JR, Idiago JM, Vergara MR, García SS, Villa Riballo A, González SG, Guisasola LM, Salvador C, San Martín ES, Gorospe A, Legarda I, Arques PN, Rodríguez MJ, Vives B, Gaston I, Ramos-Arroyo MA, Moreno JM, Peña JC, Avarvarei LD, Bastida AM, Recio MF, Vergé LR, Sánchez VS, Carrillo F, Cáceres MT, Mir P, Suarez MJ, Bosca M, Burguera JA, Garcia AC, Martínez LM, del Val JL, Loutfi G, Olofsson C, Stattin EL, Westman L, Wikström B, Höglund A, Pålhagen SE, Paucar M, Sandström B, Soltani R, Svenningsson P, Reza-Soltani TW, Constantinescu R, Fredlund G, Høsterey-Ugander U, Neleborn-Lingefjärd L, Wahlström J, Esmaeilzadeh M, Tedroff J, Winnberg E, Björn Y, Ekwall C, Gøller ML, Johansson A, Wiklund L, Petersen Å, Reimer J, Widner H, Burgunder JM, Burgunder Y, Stebler Y, Kaelin A, Romero I, Schüpbach M, Zaugg SW, Jack R, Matheson K, Miedzybrodzka Z, Rae D, Simpson S, Summers F, Ure A, Crooks J, Curtis A, de Souza Keylock J, Rickards H, Wright J, Hayward B, Sieradzan K, Wright A, Barker RA, Di Pietro A, Fisher K, Goodman A, Hill S, Kershaw A, Mason S, Paterson N, Raymond L, Bisson J, Busse M, Clenaghan C, Ellison-Rose L, Handley O, Hunt S, Townhill J, Price K, Rosser A, Edwards M, Hughes T, McGill M, Pearson P, Porteous M, Smith P, Zeman A, Causley A, Harrower T, Howcroft D, Lambord N, Rankin J, Brockie P, Foster J, Johns N, McKenzie S, Rothery J, Thomas G, Yates S, Miller J, Ritchie S, Burrows L, Fletcher A, Harding A, Laver F, Silva M, Thomson A, Burns P, Chu C, Evans C, Hamer S, Markova I, Miller J, Raman A, Barnes K, Chu C, Hobson E, Jamieson S, Markova I, Thomson J, Toscano J, Wild S, Yardumian P, Bourne C, Clayton C, Dipple H, Clapton J, Grant D, Hallam C, Middleton J, Murch A, Patino D, Bate L, Pate L, Andrews T, Dougherty A, Kavalier F, Golding C, Lashwood A, Robertson D, Ruddy D, Whaite A, Patton M, Peterson M, Rose S, Andrews T, Bruno S, Chu E, Doherty K, Golding, Fillingham K, Foustanos I, O'Donovan K, Peppa N, Tidswell K, Quarrell O.Orth, M; Handley, Oj; Schwenke, C; Dunnett, S; Wild, Ej; Tabrizi, Sj; Landwehrmeyer, Gb; Bachoud-Lévi, Ac; Bentivoglio, Ar; Biunno, I; Bonelli, R; Burgunder, Jm; Dunnett, Sb; Ferreira, Jj; Giuliano, J; Handley, Oj; Heiberg, A; Illmann, T; van Kammen, D; Landwehrmeye, Gb; Levey, J; Nielsen, Je; Päivärinta, M; Roos, Ra; Sebastián, Ar; Tabrizi, Sj; Vandenberghe, W; Verellen-Dumoulin, C; Zaremba, J; Uhrova, T; Wahlström, J; Schwenke, C; Orth, M; Illmann, T; Wallner, M; Barth, K; Guedes, Lc; Finisterra, Am; Garde, Mb; Bos, R; Burg, S; Ecker, D; Handley, Oj; Held, C; Koppers, K; Laurà, M; Descals, Am; Mclean, T; Mestre, T; Minster, S; Monza, D; Townhill, J; Orth, M; Padieu, H; Paterski, L; Peppa, N; Koivisto, Sp; Rialland, A; Røren, N; Sasinková, P; Cubillo, Pt; Tritsch, C; van Walsem, Mr; Witjes-Ané, Mn; Yudina, E; Zielonka, D; Zielonka, E; Zinzi, P; Bonelli, Rm; Herranhof, B; Holl, A; Kapfhammer, Hp; Koppitz, M; Magnet, M; Otti, D; Painold, A; Reisinger, K; Scheibl, M; Hecht, K; Lilek, S; Müller, N; Schöggl, H; Ullah, J; Brugger, F; Hepperger, C; Hotter, A; Mahlknecht, P; Nocker, M; Seppi, K; Wenning, G; Buratti, L; Hametner, Em; Holas, C; Hussl, A; Mair, K; Poewe, W; Wolf, E; Zangerl, A; Braunwarth, Em; Lilek, S; Sinadinosa, D; Walleczek, Am; Bonelli, Rm; Ladurner, G; Staffen, W; Ribaï, P; Verellen-Dumoulin, C; Flamez, A; Morez, V; de Raedt, S; Boogaerts, A; Vandenberghe, W; van Reijen, D; Klempíř, J; Kucharík, M; Roth, J; Šenkárová, Z; Hasholt, L; Hjermind, Le; Jakobsen, O; Nørremølle, A; Sørensen, Sa; Stokholm, J; Nielsen, J; Hiivola, H; Martikainen, K; Tuuha, K; Peippo, M; Sipponen, M; Ignatius, J; Kärppä, M; Åman, J; Santala, M; Allain, P; Guérid, Ma; Gohier, B; Olivier, A; Prundean, A; Scherer-Gagou, C; Verny, C; Babiloni, B; Debruxelles, S; Goizet, C; Lafoucrière, D; De Bruycker, C; Carette, As; Decorte, E; Delval, A; Delliaux, M; Dujardin, K; Peter, M; Plomhouse, L; Simonin, C; Thibault-Tanchou, S; Bellonet, M; Duru, C; Krystkowiak, P; Roussel, M; Wannepain, S; Azulay, Jp; Chabot, C; Delphini, M; Eusebio, A; Grosjean, H; Mundler, L; Nowak, M; Rudolf, G; Steinmetz, G; Tranchant, C; Wagner, C; Zimmermann, Ma; Calvas, F; Cheriet, S; Démonet, Jf; Galitzky, M; Kosinski, Cm; Milkereit, E; Probst, D; Sass, C; Schiefer, J; Schlangen, C; Werner, Cj; Gelderblom, H; Priller, J; Prüss, H; Spruth, Ej; Andrich, J; Hoffmann, R; Kraus, Ph; Muth, S; Prehn, C; Saft, C; Salmen, S; Stamm, C; Steiner, T; Strassburger, K; Lange, H; Friedrich, A; Hunger, U; Löhle, M; Schmidt, S; Storch, A; Wolz, A; Wolz, M; Lambeck, J; Zucker, B; Boelmans, K; Ganos, C; Hidding, U; Lewerenz, J; Münchau, A; Orth, M; Schmalfeld, J; Stubbe, L; Zittel, S; Diercks, G; Gorzolla, H; Schrader, C; Heinicke, W; Ribbat, M; Longinus, B; Bürk, K; Möller, Jc; Rissling, I; Peinemann, A; Städtler, M; Weindl, A; Bechtel, N; Beckmann, H; Bohlen, S; Hölzner, E; Lange, H; Reilmann, R; Rohm, S; Rumpf, S; Schepers, S; Beister, A; Dose, M; Hammer, K; Kieni, J; Leythaeuser, G; Marquard, R; Raab, T; Richter, S; Selimbegovic-Turkovic, A; Schrenk, C; Schuierer, M; Wiedemann, A; Barth, K; Buck, A; Connemann, J; Ecker, D; Eschenbach, C; Held, C; Landwehrmeyer, B; Lezius, F; Nepper, S; Niess, A; Orth, M; Süssmuth, S; Trautmann, S; Weydt, P; Cormio, C; Difruscolo, O; Sciruicchio, V; Serpino, C; de Tommaso, M; Capellari, S; Cortelli, P; Gallassi, R; Poda, R; Rizzo, G; Scaglione, C; Bertini, E; Ghelli, E; Ginestroni, A; Massaro, F; Mechi, C; Paganini, M; Piacentini, S; Pradella, S; Romoli, Am; Sorbi, S; Abbruzzese, G; di Poggio, Mb; Di Maria, E; Ferrandes, G; Mandich, P; Marchese, R; Albanese, A; Di Bella, D; Di Donato, S; Gellera, C; Genitrini, S; Mariotti, C; Monza, D; Nanetti, L; Paridi, D; Soliveri, P; Tomasello, C; De Michele, G; Di Maio, L; Rinaldi, C; Russo, Cv; Salvatore, E; Tucci, T; Cannella, M; Codella, V; De Gregorio, F; De Nicola, N; Martino, T; Simonelli, M; Squitieri, F; Bentivoglio, Ar; Catalli, C; Di Giacopo, R; Fasano, A; Frontali, M; Guidubaldi, A; Ialongo, T; Jacopini, G; Loria, G; Modoni, A; Piano, C; Chiara, P; Quaranta, D; Romano, S; Soleti, F; Spadaro, M; Zinzi, P; van Hout, Ms; van Vugt, Jp; de Weert, Am; Bolwijn, Jj; Dekker, M; Leenders, Kl; van Oostrom, Jc; Bos, R; Dumas, Em; Jurgens, Ck; van den Bogaard, Sj; Roos, Ra; 't Hart, Ep; Witjes-Ané, Mn; Kremer, B; Verstappen, Cc; Heiberg, A; van Walsem, Mr; Frich, J; Wehus, R; Aaserud, O; Borgerød, N; Bjørgo, K; Fannemel, M; Gørvell, P; Pro Koivisto, S; Retterstøl, L; Overland, T; Stokke, B; Bjørnevoll, I; Sando, Sb; Blinkenberg, Eø; Hauge, E; Tyvoll, H; Sitek, E; Slawek, J; Soltan, W; Boczarska-Jedynak, M; Jasinska-Myga, B; Opala, G; Kłodowska-Duda, G; Banaszkiewicz, K; Szczudlik, A; Rudzińska, M; Wójcik, M; Dec, M; Krawczyk, M; Bryl, A; Ciesielska, A; Klimberg, A; Marcinkowski, J; Sempołowicz, J; Zielonka, D; Samara, H; Janik, P; Kalbarczyk, A; Kwiecinski, H; Jamrozik, Z; Antczak, J; Jachinska, K; Rakowicz, M; Richter, P; Ryglewicz, D; Witkowski, G; Zdzienicka, E; Zaremba, J; Sułek, A; Krysa, W; Júlio, F; Januário, C; Mestre, T; Guedes, L; Coelho, M; Mendes, T; Valadas, A; Ferreira, Jj; Timóteo, Â; Costa, C; Vale, J; Cavaco, S; Damásio, J; Magalhães, M; Gago, M; Garrett, C; Guerra, Mr; Solis, P; Herrera, Cd; Garcia, Pm; Barrero, F; Morales, B; Cubo, E; Mariscal, N; Alonso-Frech, F; Perez, Mr; Fenollar, M; García, Rg; Quiroga, Pp; Rivera, Sv; Villanueva, C; Bascuñana, M; Ventura, Mf; Ribas, Gg; de Yébenes, Jg; Moreno, Jl; Cubillo, Pt; Ruíz, Pj; Martínez-Descals, A; Artiga, Mj; Sánchez, V; Perea, Mf; Lorenza, F; Torres, Mm; Reinante, G; Moreau, Lv; Barbera, Ma; Guia, Db; Hernanz, Lc; Catena, Jl; Sebastián, Ar; Ferrer, Pq; Carruesco, Gt; Bas, J; Busquets, N; Calopa, M; Buongiorno, Mt; Muñoz, E; Elorza, Md; López, Cd; Terol, Sd; Robert, Mf; Ruíz, Bg; Casado, Ag; Martínez, Ih; Viladrich, Cm; Pons, i Càrdenas R; Roca, E; Llesoy, Jr; Idiago, Jm; Vergara, Mr; García, Ss; Villa Riballo, A; González, Sg; Guisasola, Lm; Salvador, C; San Martín, Es; Gorospe, A; Legarda, I; Arques, Pn; Rodríguez, Mj; Vives, B; Gaston, I; Ramos-Arroyo, Ma; Moreno, Jm; Peña, Jc; Avarvarei, Ld; Bastida, Am; Recio, Mf; Vergé, Lr; Sánchez, Vs; Carrillo, F; Cáceres, Mt; Mir, P; Suarez, Mj; Bosca, M; Burguera, Ja; Garcia, Ac; Martínez, Lm; del Val, Jl; Loutfi, G; Olofsson, C; Stattin, El; Westman, L; Wikström, B; Höglund, A; Pålhagen, Se; Paucar, M; Sandström, B; Soltani, R; Svenningsson, P; Reza-Soltani, Tw; Constantinescu, R; Fredlund, G; Høsterey-Ugander, U; Neleborn-Lingefjärd, L; Wahlström, J; Esmaeilzadeh, M; Tedroff, J; Winnberg, E; Björn, Y; Ekwall, C; Gøller, Ml; Johansson, A; Wiklund, L; Petersen, Å; Reimer, J; Widner, H; Burgunder, Jm; Burgunder, Y; Stebler, Y; Kaelin, A; Romero, I; Schüpbach, M; Zaugg, Sw; Jack, R; Matheson, K; Miedzybrodzka, Z; Rae, D; Simpson, S; Summers, F; Ure, A; Crooks, J; Curtis, A; de Souza Keylock, J; Rickards, H; Wright, J; Hayward, B; Sieradzan, K; Wright, A; Barker, Ra; Di Pietro, A; Fisher, K; Goodman, A; Hill, S; Kershaw, A; Mason, S; Paterson, N; Raymond, L; Bisson, J; Busse, M; Clenaghan, C; Ellison-Rose, L; Handley, O; Hunt, S; Townhill, J; Price, K; Rosser, A; Edwards, M; Hughes, T; Mcgill, M; Pearson, P; Porteous, M; Smith, P; Zeman, A; Causley, A; Harrower, T; Howcroft, D; Lambord, N; Rankin, J; Brockie, P; Foster, J; Johns, N; Mckenzie, S; Rothery, J; Thomas, G; Yates, S; Miller, J; Ritchie, S; Burrows, L; Fletcher, A; Harding, A; Laver, F; Silva, M; Thomson, A; Burns, P; Chu, C; Evans, C; Hamer, S; Markova, I; Miller, J; Raman, A; Barnes, K; Chu, C; Hobson, E; Jamieson, S; Markova, I; Thomson, J; Toscano, J; Wild, S; Yardumian, P; Bourne, C; Clayton, 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Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (&gt;59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30\u201350 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of 6435 or a UHDRS motor score of 645 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P &lt;.001). Overall motor and cognitive performance (P &lt;.001) were worse, however only disease motor progression was slower (coefficient, 120.58; SE 0.16; P &lt;.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P &lt;.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P &lt;.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589