Tissue-dependent regulation of RNAP II dynamics: the missing link between transcription and trinucleotide repeat instability in diseases?

More than 15 human genetic diseases, including Huntington's disease, result from the expansion of a trinucleotide repeat. The expansions are unstable in specific somatic tissues, which can lead to disease acceleration. Here we discuss the role of transcription elongation in tissue-selective trinucleotide repeat instability.