Transcriptional dysregulation is believed to be a common attribute of polyQ disorders. However, the precise causes of transcriptional alterations and how they relate to the observed phenotype remain unclear. Transcriptional impairment differs in different diseases, possibly reflecting the specific functions of the disease-causing proteins. Various aberrant interactions between expanded polyglutamine proteins and transcriptional factors and co-factors have been revealed, such as CREB-binding protein, p300/CBP-associated factor, p53, Sp1, TAFII130, PQBP-1, etc.