Clinical improvement of DM1 patients reflected by reversal of disease-induced gene expression in blood

Abstract

Myotonic dystrophy type 1 (DM1) is an incurable multisystem disease caused by a CTG-repeat expansion in the DM1 protein kinase (DMPK) gene. The OPTIMISTIC clinical trial demonstrated positive and heterogenous effects of cognitive behavioral therapy (CBT) on the capacity for activity and social participations in DM1 patients. Here, we performed mRNA sequencing of full blood for 27 patients of the OPTIMISTIC cohort before and after the CBT intervention. We identified 608 genes for which their expression was significantly associated with the disease causing CTG-repeat expansion, as well as 1176 genes significantly associated with the average clinical response towards the intervention. Remarkably, all 97 genes significantly associated with both returned to more normal levels in patients who benefited most from CBT. This trend was consistent with the difference observed between DM1 patients and controls in an earlier study of blood mRNA expression levels, singling these genes out as candidate biomarkers for therapy response. Together these results highlight the ability to find disease relevant information in full blood of DM1 patients, opening new avenues to monitor therapy effects.