Sophie Tezenas du Montcel, Alexandra Durr, Peter Bauer, Karla P Figueroa, Yaeko Ichikawa, Alessandro Brussino, Sylvie Forlani, Maria Rakowicz, Ludger Schöls, Caterina Mariotti, Bart P C van de Warrenburg, Laura Orsi, Paola Giunti, Alessandro Filla, Sandra Szymanski, Thomas Klockgether, José Berciano, Massimo Pandolfo, Sylvia Boesch, Bela Melegh, Dagmar Timmann, Paola Mandich, Agnès Camuzat, Jun Goto, Tetsuo Ashizawa, Cécile Cazeneuve, Shoji Tsuji, Stefan-M Pulst, Alfredo Brusco, Olaf Riess, Alexis Brice, Giovanni Stevanin
Polyglutamine-coding (CAG)n repeat expansions in seven different genes cause spinocerebellar ataxias. Although the size of the expansion is negatively correlated with age at onset, it accounts for only 50-70% of its variability. To find other factors involved in this variability, we performed a regression analysis in 1255 affected individuals with identified expansions (spinocerebellar ataxia types 1, 2, 3, 6 and 7), recruited through the European Consortium on Spinocerebellar Ataxias, to determine whether age at onset is influenced by the size of the normal allele in eight causal (CAG)n-containing genes (ATXN1-3, 6-7, 17, ATN1 and HTT)...
September 2014: Brain