Exploring Genetic Factors Involved in Huntington Disease Age of Onset: E2F2 as a New Potential Modifier Gene. oleh Leire Valcárcel-Ocete, Gorka Alkorta-Aranburu, Mikel Iriondo, Asier Fullaondo, María García-Barcina, José Manuel Fernández-García, Elena Lezcano-García, José María Losada-Domingo, Javier Ruiz-Ojeda, Amaia Álvarez de Arcaya, José María Pérez-Ramos, Raymund A C Roos, Jørgen E Nielsen, Carsten Saft, REGISTRY investigators of the European Huntington's Disease Network, Ana M Zubiaga, Ana Aguirre