Background Enroll-HD is a clinical research platform that includes at its core an observational, prospective study of HD. The objectives of Enroll-HD are: 1) enhance the design and expedite the conduct of clinical trials; 2) improve the understanding of the phenotypic spectrum and disease mechanisms; 3) foster good clinical care.

Over 17,200 participants (15,466 currently active) have been recruited from 17 countries and 161 study sites. The data collected from these participants is monitored using a rigorous risk-based process. Recoded data and biosamples are made available to researchers. Enroll-HD also serves as a registry that can be used to facilitate recruitment, by identifying potentially eligible participants who can be invited by investigators to participate in clinical trials. Selection criteria (e.g. local CAG, UHDRS TMS) can be queried to generate listings of participants potentially eligible for a given clinical trial. To improve support for future clinical trials, the study will now start to prioritize the recruitment of premanifest and early-stage participants. Platform studies are clinical studies that utilize at least one or more Enroll-HD platform services. These services include site feasibility, study guidance documents and templates, potentially eligible participant listings, study set-up support, monitoring and data management.

The Enroll-HD Clinical Training Portal is an online resource launched in January 2017 where HD research personnel can complete and maintain study-relevant training, presently UHDRS Motor Certification (all users) and GCP (Enroll-HD Study users only). There are currently more than 1300 registered users, and it enables faster, more cost-effective start-up of clinical trials and studies, standardizes the quality of training, and reduces workload at sites.