DNA methylation profiling across brain regions in Huntington’s disease.

Huntington’s disease (HD) is an autosomal dominant condition that occurs due to the expansion of a CAG trinucleotide repeat in the Huntingtin (HTT) gene. The translated HTT protein has an expanded polyglutamine sequence thought to cause deleterious effects. These effects cause severe neurodegeneration in the striatum. In HD there is also clear atrophy in the cerebellum and a reduction in cortical thickness, including in the entorhinal cortex (EC). Epigenome wide association studies (EWAS) of DNA methylation differences in HD have thus far been limited to the cerebral cortex and use older technologies such as the Illumina 450K array. In this study, we performed an EWAS of HD in the striatum, EC and cerebellum, using the Illumina EPIC methylation array to profile 850, 000 sites across the genome.